Log list: tighter rows, badges no longer set the line height

Rows drop from ~29px to ~24px (normal density, medium font) and from
~18.6px to ~18px in compact; long messages still wrap.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

.env.example

@@ -1,6 +1,6 @@
 # Copy this file to .env and adjust it.
-SYSLOG_PORT=514
-HTTP_PORT=8080
+SYSLOG_PORT=5514
+HTTP_PORT=8989
 TZ=Europe/Paris
 # How long logs are kept (e.g. 7d, 30d, 12w, 1y)
 RETENTION=30d
@@ -9,9 +9,17 @@ AUTH_MODE=local
 # local mode: user and password (empty = no authentication)
 AUTH_USER=
 AUTH_PASS=
+# local mode: optional read-only account (can search and export, cannot change tags, sources or purge)
+AUTH_VIEWER_USER=
+AUTH_VIEWER_PASS=
 # local mode: PNG logo shown on the login page, path inside the container (empty = no logo).
 # Mount the file in docker-compose.yml, e.g. ./logo.png:/config/logo.png:ro, then LOGIN_LOGO=/config/logo.png
 LOGIN_LOGO=
+
+# Ready-made color tags offered in Settings > Filters (see docs/presets.md).
+# Empty: /data/presets.json if present, else the built-in list. To use your own file,
+# mount it in docker-compose.yml, e.g. ./presets.json:/config/presets.json:ro
+PRESETS_FILE=
 # Session lifetime, both modes (e.g. 8h, 24h)
 SESSION_TTL=12h
 # oidc mode: issuer URL exactly as the provider announces it
@@ -23,12 +31,16 @@ OIDC_CLIENT_SECRET=
 OIDC_REDIRECT_URL=https://logs.example.org/auth/callback
 # Requested scopes (openid is always added)
 OIDC_SCOPES=openid profile email
+# oidc mode: only members of this group are admins, the others are read-only (empty = everyone is admin).
+# The groups come from the ID token claim OIDC_GROUPS_CLAIM (default groups)
+OIDC_ADMIN_GROUP=
+OIDC_GROUPS_CLAIM=groups
 # Reverse DNS: show host names instead of IP addresses (on/off)
 RDNS=on
 # DNS server used for reverse lookups (e.g. your router: 192.168.1.1). Empty = system resolver
 DNS_SERVER=
 # Allow "Delete all logs" in Settings (true/false)
-ALLOW_PURGE=true
+ALLOW_PURGE=false
 # Maximum number of rows in a CSV export
 EXPORT_MAX=100000
 # Collect the logs of the Docker containers of this machine (on/off)
@@ -41,3 +53,21 @@ DOCKER_BACKFILL=1h
 HOST_LOGS_GID=4
 # History read when the source is turned on (e.g. 30m, 1h, 24h; 0 = only new entries)
 HOST_LOGS_BACKFILL=1h
+# Kernel messages of the host (dmesg, enable them in Settings > Sources). The container needs
+# /dev/kmsg: uncomment "devices" in docker-compose.yml. When the host has
+# kernel.dmesg_restrict=1 (default on Debian/Ubuntu), either run on the host
+#   sysctl -w kernel.dmesg_restrict=0   (persist it in /etc/sysctl.d/)
+# or run the container as root with the SYSLOG capability ("user" and "cap_add" in docker-compose.yml).
+# History read when the source is turned on (e.g. 30m, 1h, 24h; 0 = only new messages)
+DMESG_BACKFILL=1h
+# Linux audit log of the host (auditd, enable it in Settings > Sources). Uncomment the
+# /var/log/audit volume in docker-compose.yml and let the container read the file:
+# log_group = adm in /etc/audit/auditd.conf, and chgrp adm + chmod 750 on /var/log/audit.
+# History read when the source is turned on (e.g. 30m, 1h, 24h; 0 = only new events)
+AUDIT_BACKFILL=1h
+# Host name of the audit events (empty: node= of the records, else /host/etc/hostname, else localhost)
+AUDIT_HOST=
+# Log files of other programs (Traefik, nginx, applications…), declared in Settings > Log sources >
+# Log files: mount their directory read-only in docker-compose.yml (e.g. /var/log/traefik:/logs/traefik:ro).
+# History read when a file is turned on (e.g. 30m, 1h, 24h; 0 = only new lines)
+FILES_BACKFILL=1h

Dockerfile

@@ -4,7 +4,7 @@
 FROM golang:1.27.1-alpine3.24 AS build
 WORKDIR /src
 COPY go.mod ./
-COPY *.go ./
+COPY *.go presets.json ./
 COPY web ./web
 RUN CGO_ENABLED=0 go build -trimpath -ldflags="-s -w" -o /out/logstream .
 

README.fr.md

@@ -18,8 +18,10 @@ devices ──514 udp/tcp──▶ logstream (Go) ──HTTP batches──▶ Vi
 ![Schéma logique de Logstream](docs/architecture.png)
 
 - **Ingestion** : les messages syslog (UDP/TCP) et les logs des conteneurs Docker passent tous
-  par `sink()` (résolution DNS inverse des hôtes donnés par leur IP), puis par la file du
-  `Store`, qui les envoie par lots à VictoriaLogs.
+  par `sink()` (résolution DNS inverse des hôtes donnés par leur IP, sans bloquer la
+  réception), puis par la file du `Store`, qui les envoie par lots à VictoriaLogs. Quand
+  VictoriaLogs est injoignable, les lots sont gardés sur disque (`/data/spool`, jusqu'à
+  `SPOOL_MAX_MB`) et renvoyés, les plus anciens d'abord, dès son retour.
 - **Direct** : `sink()` publie aussi chaque message dans le `Hub`, qui le diffuse aux
   navigateurs en SSE.
 - **Recherche** : l'API HTTP traduit les filtres de l'interface en requêtes LogsQL envoyées à
@@ -53,7 +55,7 @@ Ouvrez ensuite <http://localhost:8080>.
 - **Test manuel** : `logger -n 127.0.0.1 -P 514 -d "hello error"` (util-linux) ou
   `echo "<14>test ok" | nc -u -w1 127.0.0.1 514`.
 
-**Paramètres > Sources > Syslog** active ou désactive la réception syslog et choisit les
+**Paramètres > Sources de logs > Syslog** active ou désactive la réception syslog et choisit les
 protocoles (UDP, TCP) sans redémarrage ; le choix est enregistré dans `/data/syslog.json`. Cet
 onglet affiche aussi l'état d'écoute (et l'erreur si le port est déjà utilisé). Le port
 lui-même est publié par docker-compose : modifiez `SYSLOG_PORT` dans `.env`, puis lancez
@@ -90,16 +92,30 @@ une base propre.
 Les badges de sévérité `err`/`crit` et `warning` reprennent les couleurs des tags `error` et
 `warning`.
 
+Chaque ligne commence par un badge de largeur fixe qui indique sa source, avec une couleur par
+source : **SYSLOG**, **DOCKER**, **KERNEL** (dmesg), **HOST** (fichiers de `/var/log`), **AUDIT**,
+**FILE** et **LS** (logs de LogStream lui-même).
+
 Raccourcis : `/` place le curseur dans la recherche, `Esc` la vide. Un clic sur une ligne
 affiche tous ses champs.
 
 Les en-têtes de colonnes restent visibles pendant le défilement. Faites glisser le bord d'un
 en-tête (réception, heure message, sévérité, hôte, app) pour redimensionner la colonne, et
 double-cliquez dessus pour revenir à la largeur automatique ; le message occupe l'espace
-restant. Les largeurs sont mémorisées par le navigateur (**Paramètres > Interface >
+restant. Les largeurs sont mémorisées par le navigateur (**Paramètres > Affichage >
 Réinitialiser les colonnes** les rétablit toutes). Sur téléphone, la liste garde sa
 présentation sur deux lignes, sans colonnes.
 
+## Modes Flux et Période
+
+Le premier contrôle de la barre de filtres bascule entre deux modes d'affichage :
+
+- **Flux** : les derniers logs sur une durée glissante (5 min à 30 jours, ou tout), avec le direct.
+- **Période** : les logs entre une date de début et une date de fin, saisies dans le fuseau choisi
+  dans les Paramètres. ◀ et ▶ passent à la période précédente ou suivante de même durée, la loupe
+  la double autour de son milieu. Le direct se met en pause ; le mode et la période sont conservés
+  au rechargement.
+
 ## Frise
 
 La frise au-dessus de la liste montre le volume de logs par intervalle, compté selon l'**heure
@@ -107,15 +123,14 @@ de réception** sur l'horloge du serveur (elle correspond donc aux heures affich
 lignes).
 
 - Au survol d'un intervalle : ses bornes, son total et le détail par sévérité.
-- Un clic sur une barre zoome sur cet intervalle ; un glisser sur plusieurs barres zoome sur la
-  sélection. La plage de temps affiche alors la période zoomée (« × Annuler le zoom » ou le
-  choix d'une autre plage en sort) ; la liste, les compteurs et l'export CSV suivent le zoom,
-  et le direct se met en pause.
+- Un clic sur une barre affiche cet intervalle en mode Période ; un glisser sur plusieurs barres
+  affiche la sélection. « × Revenir au flux » repasse en mode Flux. La liste, les compteurs et
+  l'export CSV suivent la période.
 - En direct, le dernier intervalle grandit à l'arrivée des messages, et la frise se recharge à
   chaque nouvel intervalle. Rien n'est rafraîchi tant que l'onglet du navigateur est masqué ;
   la frise se met à jour dès qu'il redevient visible.
 
-**Paramètres > Interface > Frise** (mémorisé par navigateur) : échelle (linéaire, √ par défaut,
+**Paramètres > Affichage > Frise** (mémorisé par navigateur) : échelle (linéaire, √ par défaut,
 log), hauteur (S/M/L : 40/80/120 px), couleur (empilement par sévérité, intensité comparée à
 la médiane de la fenêtre : calme, rafale au-delà de 3×, anomalie au-delà de 10×, ou aucune),
 barres ou aire, division (automatique, environ 100 intervalles, ou fixe : 1 s, 10 s, 1 min,
@@ -144,7 +159,7 @@ colorés et exportés comme les messages syslog :
   (`"level":"error"`), logfmt (`level=warn`), `[ERROR]`, ou un niveau en majuscules au début de
   la ligne (`ERROR`, `WARN`…). Sinon, elle vaut `info`. Les codes de couleur du terminal sont
   supprimés.
-- **Paramètres > Sources** affiche une étiquette par conteneur (`project/service`) dans un seul
+- **Paramètres > Sources de logs** affiche une étiquette par conteneur (`project/service`) dans un seul
   champ : les conteneurs suivis en couleur, puis les non suivis en gris ; un clic bascule une
   étiquette. La couleur identifie le projet compose, et les noms d'applications Docker de la
   liste utilisent la même couleur. Les conteneurs arrêtés sont masqués par défaut (« Afficher
@@ -153,8 +168,10 @@ colorés et exportés comme les messages syslog :
   quand les conteneurs sont nombreux. Les nouveaux conteneurs sont suivis automatiquement, sauf
   si cette option est désactivée. Les choix sont enregistrés par service compose (ou nom de
   conteneur) dans `/data/docker.json` : ils survivent aux recréations.
-- Logstream mémorise la position lue dans chaque conteneur (`/data/docker-state.json`) : après
-  un redémarrage, il reprend sans perdre ni dupliquer de lignes. Un conteneur vu pour la
+- Logstream mémorise la position de la dernière ligne stockée pour chaque conteneur
+  (`/data/docker-state.json`) : après un redémarrage, il reprend sans perdre de lignes. La
+  position n'avance qu'une fois la ligne dans VictoriaLogs ou dans le tampon disque, et une file
+  pleine ralentit la lecture au lieu de perdre des lignes. Un conteneur vu pour la
   première fois est lu à partir de `DOCKER_BACKFILL` en arrière (1 heure par défaut).
 - Logstream lui-même et le proxy ci-dessous ne sont jamais collectés ; ajoutez l'étiquette
   `logstream.exclude=true` à tout autre conteneur pour l'exclure définitivement.
@@ -168,7 +185,7 @@ moteur (`GET` uniquement).
 
 Logstream peut aussi collecter les logs système de la machine qui héberge la stack, sans rien
 configurer sur l'hôte. La source est **désactivée par défaut** : activez-la dans
-**Paramètres > Sources > Logs système de l'hôte** (enregistré dans `/data/hostlogs.json`).
+**Paramètres > Sources de logs > Logs système de l'hôte** (enregistré dans `/data/hostlogs.json`).
 
 - `docker-compose.yml` monte `/var/log` et `/run/log/journal` en lecture seule sous `/host`.
 - Si l'hôte utilise systemd, Logstream lit directement les fichiers du **journal systemd**
@@ -183,13 +200,176 @@ configurer sur l'hôte. La source est **désactivée par défaut** : activez-la
 - **Droits** : le conteneur tourne avec un utilisateur sans privilège et reçoit le groupe `adm`
   (gid 4), qui peut lire le journal et `/var/log` sur Debian et Ubuntu. Sur d'autres systèmes,
   réglez `HOST_LOGS_GID` dans `.env` sur le gid de `systemd-journal`
-  (`getent group systemd-journal | cut -d: -f3`). Paramètres > Sources affiche un message clair
+  (`getent group systemd-journal | cut -d: -f3`). Paramètres > Sources de logs affiche un message clair
   si l'accès est refusé.
 - Limites : les champs du journal compressés par journald (messages de plus de 512 octets,
   compressés en zstd/lz4/xz) ne peuvent pas être décodés sans bibliothèque supplémentaire ; ils
   sont comptés dans les Paramètres et affichés comme « (compressed journal entry) ». Les fichiers
   texte tournés ou compressés (`*.1`, `*.gz`) ne sont pas lus.
 
+## Messages du noyau (dmesg)
+
+Logstream peut collecter le buffer circulaire du noyau de l'hôte (ce qu'affiche `dmesg` :
+matériel, pilotes, OOM killer, pare-feu…) en lisant `/dev/kmsg`. La source est **désactivée par
+défaut** : activez-la dans **Paramètres > Sources de logs > Messages du noyau (dmesg)** (enregistré dans
+`/data/dmesg.json`).
+
+- **Périphérique** : le conteneur ne voit pas `/dev/kmsg` par défaut. Décommentez la section
+  `devices` de `docker-compose.yml` (`/dev/kmsg:/dev/kmsg:r`, en lecture seule), puis
+  `docker compose up -d`.
+- **Droits** : si l'hôte a `kernel.dmesg_restrict=1` (le défaut sur Debian et Ubuntu), seuls
+  les processus qui ont la capacité `CAP_SYSLOG` peuvent lire le log du noyau, et le conteneur
+  tourne avec un utilisateur sans privilège. Au choix :
+  - l'autoriser sur l'hôte : `sysctl -w kernel.dmesg_restrict=0`, conservé au redémarrage avec
+    `echo kernel.dmesg_restrict=0 | sudo tee /etc/sysctl.d/50-dmesg.conf` (tous les
+    utilisateurs de l'hôte peuvent alors lancer `dmesg`) ; ce réglage ne peut pas être changé
+    depuis un conteneur ;
+  - ou lancer Logstream en root avec la capacité `SYSLOG` : décommentez `user: "0:0"` et
+    `cap_add: [SYSLOG]` dans `docker-compose.yml`.
+
+  Paramètres > Sources de logs indique si le périphérique est absent ou l'accès refusé ; le reste de
+  Logstream continue de fonctionner et le périphérique est réessayé toutes les 10 secondes.
+- **Champs** : **app** vaut `kernel` (ou le nom du programme pour les messages écrits par des
+  programmes, comme `systemd[1]: …`), la sévérité et la facility viennent de l'enregistrement,
+  **host** vaut `localhost`, `subsystem` et `device` sont conservés quand le noyau les fournit.
+  Ces logs ont la source `kernel` (`proto` `kmsg`) : le filtre **Source** permet de les afficher
+  seuls.
+- **Heure** : les enregistrements portent le temps écoulé depuis le démarrage ; Logstream le
+  convertit en date grâce à l'heure de démarrage (`/proc/uptime`). Comme avec `dmesg -T`,
+  l'heure peut être trop tôt après une mise en veille de l'hôte.
+- À l'activation, la dernière heure est lue d'abord (`DMESG_BACKFILL`, `0` = seulement les
+  nouveaux messages). Le numéro de séquence du dernier message et l'identifiant de démarrage
+  sont enregistrés dans `/data/dmesg-state.json` : après un redémarrage de Logstream, la lecture
+  reprend après le dernier message (sans doublon) ; après un redémarrage de l'hôte, le nouveau
+  buffer est lu depuis `DMESG_BACKFILL`. Les messages écrasés dans le buffer du noyau avant
+  d'être lus sont comptés dans Paramètres.
+
+## Audit Linux (auditd)
+
+Logstream peut suivre le journal du démon d'audit Linux (`/var/log/audit/audit.log`) :
+connexions, `sudo`, fichiers surveillés, appels système visés par vos règles `auditctl`… La
+source est **désactivée par défaut** : activez-la dans **Réglages > Sources > Audit Linux
+(auditd)**, où le chemin du fichier peut aussi être changé (enregistré dans `/data/audit.json` ;
+`AUDIT_LOG` fixe le chemin par défaut).
+
+- **Montage** : décommentez `/var/log/audit:/var/log/audit:ro` dans `docker-compose.yml`, puis
+  `docker compose up -d`. (`/var/log` est déjà monté sous `/host` pour les logs système de
+  l'hôte : `/host/var/log/audit/audit.log` fonctionne donc aussi comme chemin, sans nouveau
+  volume.)
+- **Droits** (côté hôte) : auditd écrit son journal en `root`, mode `0600`, dans un répertoire
+  `0700`, et Logstream tourne avec l'UID `10001`. Le plus fiable est le groupe que le conteneur
+  reçoit déjà pour les logs de l'hôte (`HOST_LOGS_GID`, `adm` par défaut) :
+  ```bash
+  sudo sed -i 's/^log_group.*/log_group = adm/' /etc/audit/auditd.conf
+  sudo chgrp adm /var/log/audit && sudo chmod 750 /var/log/audit
+  sudo service auditd restart        # systemctl refuse de redémarrer auditd sur certaines distributions
+  ```
+  auditd crée alors chaque fichier, rotations comprises, en mode `0640` avec le groupe `adm`.
+  Une ACL fonctionne aussi
+  (`sudo setfacl -m u:10001:rx /var/log/audit && sudo setfacl -m u:10001:r /var/log/audit/audit.log`)
+  mais doit être réappliquée à chaque nouveau fichier après une rotation. Réglages > Sources
+  indique si le fichier est absent ou l'accès refusé ; il est réessayé chaque seconde.
+- **Événements** : les enregistrements d'un même événement (`SYSCALL`, `EXECVE`, `CWD`, `PATH`,
+  `PROCTITLE`…) partagent le même `msg=audit(heure:numéro)` et deviennent **un seul** log, dès
+  qu'aucun enregistrement n'est arrivé depuis 2 secondes. Le message est un résumé — qui, quoi,
+  résultat — comme `cedric (as root): exec apt install nginx [exec] → success` ou
+  `bob: PAM:authentication via /usr/sbin/sshd from 203.0.113.9 on ssh → failed` ; les
+  enregistrements bruts sont gardés dans `audit_raw` et affichés sous le résumé (repliés en
+  densité compacte tant que la ligne n'est pas ouverte). Les valeurs hexadécimales
+  (`proctitle`, `cmd`, arguments avec espaces) sont décodées.
+- **Champs** : `audit_type` (type du premier enregistrement, aussi utilisé comme **app**),
+  `audit_serial`, `auid` (identifiant de l'utilisateur connecté), `user` (son nom, ou l'uid s'il
+  ne peut pas être résolu), `exe`, `res` (`success` / `failed`, d'après `res=` ou `success=`) et
+  `key` (clé de la règle). La sévérité est `warning` en cas d'échec, `info` sinon ; facility
+  `authpriv` ; source `audit`. Dans la liste, les lignes d'audit ont un liseré gauche violet,
+  un fond légèrement teinté et le badge de source **AUDIT** ; le filtre **Source** permet de
+  les afficher seules.
+- **Noms** : `user` vient du format enrichi (`log_format = ENRICHED`, le défaut des versions
+  récentes d'auditd), sinon du `/etc/passwd` de l'hôte s'il est monté en `/host/etc/passwd`.
+  **host** est le `node=` des enregistrements (`name_format = hostname` dans `auditd.conf`),
+  sinon `AUDIT_HOST`, sinon `/host/etc/hostname`, sinon `localhost`.
+- À l'activation, la dernière heure est lue d'abord (`AUDIT_BACKFILL`, `0` = seulement les
+  nouveaux événements). L'inode et une position avant laquelle tout événement a été envoyé sont
+  enregistrés dans `/data/audit-state.json` : après un redémarrage, la lecture reprend là ;
+  après une rotation par auditd, la fin de `audit.log.1` est lue avant le nouveau fichier.
+
+## Fichiers de logs (Traefik, nginx, applications…)
+
+Logstream peut suivre les fichiers de logs d'autres programmes : Traefik, nginx, Apache, ou
+toute application qui écrit dans un fichier. Déclarez chaque fichier dans **Paramètres > Sources
+de logs > Fichiers de logs** (enregistré dans `/data/files.json`, 50 au plus) : un **nom** (l'**app**
+de ses entrées, par défaut le nom du fichier), le **chemin** du fichier tel que monté dans le
+conteneur, un **format** (*Automatique* par défaut), un **hôte** facultatif (par défaut
+`/host/etc/hostname`, sinon `localhost`) et un interrupteur.
+
+- **Montage** du dossier en lecture seule, par ex. dans `docker-compose.yml` :
+  `- /var/log/traefik:/logs/traefik:ro`, puis `docker compose up -d`. Les fichiers de `/var/log`
+  sont déjà accessibles sous `/host/var/log/…`. Les fichiers doivent être lisibles par l'UID
+  `10001` ou le groupe de `HOST_LOGS_GID` (`adm` par défaut) ; Paramètres > Sources de logs
+  indique quand aucun fichier ne correspond ou que l'accès est refusé.
+- **Chemin** : un fichier, par ex. `/logs/traefik/access.log` (pas de jokers). Dès la saisie, le
+  fichier est vérifié : trouvé ou non, lisible ou non, son format détecté et sa dernière ligne.
+- **Détection du format** (*Automatique*) : à partir des dernières lignes du fichier (50 au
+  plus), le format structuré que suivent au moins 80 % d'entre elles — accès Traefik JSON, JSON
+  lines, journal d'accès CLF, logfmt — sinon texte brut. Elle est refaite quand le format est
+  changé ; le format trouvé s'affiche dans l'état du fichier. Choisissez un autre format pour
+  le forcer (une expression régulière n'est jamais détectée).
+- **Formats** :
+  - *Texte brut* : une entrée par ligne ; le niveau est détecté comme pour les logs Docker, un
+    horodatage en début de ligne (ISO 8601, `2006/01/02 15:04:05`, `[02/Jan/2006:15:04:05 +0200]`,
+    `Jan  2 15:04:05`) devient l'heure du message et est retiré du message. Les lignes indentées
+    (stack traces) sont rattachées à l'entrée précédente.
+  - *JSON lines* : `msg` / `message`, `time` / `ts` / `@timestamp` (texte ou heure Unix) et
+    `level` (mot ou nombre, pino/bunyan compris) sont reconnus ; les autres clés deviennent des
+    champs, les objets imbriqués avec des noms pointés (`req.id`).
+  - *logfmt* : paires `clé=valeur`, comme les logs par défaut de Traefik ou des programmes Go ;
+    mêmes clés que le JSON.
+  - *Journal d'accès (CLF)* : Common / Combined Log Format de nginx et Apache, et le journal
+    d'accès de Traefik dans ce format (routeur, URL du serveur et durée compris). Champs
+    `client_ip`, `http_method`, `http_path`, `http_status`, `http_size`, `user_agent`,
+    `http_referer`, `router`, `backend`, `duration_ms`.
+  - *Accès Traefik (JSON)* : le journal d'accès JSON de Traefik (`accessLog.format: json`),
+    résumé en `GET app.example.com/ 200 · 12.5 ms · app@docker · 203.0.113.9`, toutes les clés
+    dans les champs. Les logs de Traefik lui-même dans le même fichier sont lus comme du JSON.
+  - *Expression régulière* (syntaxe RE2 / Go) : les groupes nommés `time`, `level`, `msg`,
+    `host` et `app` remplissent ces champs, `status` donne le niveau d'un journal d'accès, les
+    autres groupes deviennent des champs, par ex.
+    `^(?P<time>\S+ \S+) \[(?P<level>\w+)\] (?P<module>\S+): (?P<msg>.*)$`. Une ligne qui ne
+    correspond pas est rattachée à l'entrée précédente.
+
+  Pour les journaux d'accès, les statuts 5xx sont en `err`, les 4xx en `warning`, les autres en
+  `info`. Une ligne qui ne suit pas le format choisi est gardée comme du texte brut. Les champs
+  qui portent le nom d'un champ de LogStream (`host`, `app`…) sont renommés `field_host`,
+  `field_app`…
+- **Affichage** : source `file`, le chemin dans `log_file`. Dans la liste, ces lignes ont un
+  liseré gauche vert, une légère teinte et le badge de source **FILE** ; le filtre **Source**
+  les affiche seules.
+- À l'activation d'un fichier, les lignes de la dernière heure déjà présentes sont lues d'abord
+  (`FILES_BACKFILL`, `0` = seulement les nouvelles lignes ; les lignes sans horodatage sont alors
+  ignorées). Le début de cette heure est trouvé par dichotomie sur les dates des lignes : un gros
+  fichier qui contient des mois de logs n'est pas relu depuis son début ; un fichier créé ensuite
+  est lu depuis son début, jusqu'à 64 Mo par seconde, l'état indiquant ce qu'il reste à lire. L'inode et une
+  position sont enregistrés par fichier dans `/data/files-state.json` : après un redémarrage la
+  lecture reprend là ; après une rotation (`access.log` renommé `access.log.1`), la fin de
+  l'ancien fichier est lue avant le nouveau ; un fichier vidé sur place (`copytruncate`) est
+  relu depuis son début.
+
+## Logs internes de LogStream
+
+Logstream enregistre ses propres événements comme des logs, avec l'**hôte** `logstream`,
+l'**app** du composant (`store`, `syslog`, `docker`, `host`, `dmesg`, `audit`, `files`, `main`) et la
+source `logstream` : VictoriaLogs injoignable puis de retour, lots perdus, lots refusés depuis
+le tampon disque, erreurs du listener syslog, API Docker ou flux d'un conteneur décrochés,
+sources qui ne peuvent pas lire, démarrage et arrêt. Ils sont actifs par défaut à partir du
+niveau **warning** ; **Réglages > Sources > Logs internes de LogStream** permet de les couper
+ou de changer le niveau minimal (enregistré dans `/data/selflog.json`). Un même événement
+(composant et message) est enregistré au plus une fois toutes les 30 secondes, avec le nombre
+de répétitions écartées ; les événements passent par une file bornée et n'attendent jamais le
+stockage : un VictoriaLogs injoignable ne peut ni les accumuler ni les faire boucler. Tout
+continue d'aller dans `docker compose logs logstream` comme avant. Dans la liste, ces lignes
+ont un liseré gauche turquoise et un badge **LS** devant l'app ; le filtre **Source** permet de
+les afficher seules.
+
 ## Export CSV
 
 Le bouton **Exporter** (à côté du nombre de logs) télécharge tous les logs stockés qui
@@ -212,35 +392,43 @@ En ligne de commande : `curl -o logs.csv 'localhost:8080/api/export.csv?q=error&
 
 ## Paramètres
 
-L'icône en forme d'engrenage ouvre les paramètres, organisés en onglets. Tout, sauf les tags de
-couleur, est mémorisé par navigateur.
+L'icône en forme d'engrenage ouvre les paramètres, organisés en onglets. Les modifications
+s'affichent tout de suite mais ne sont conservées qu'avec le bouton **Valider**, sous les libellés
+des onglets : il prend la couleur d'accent tant que des modifications sont en attente. **Annuler**
+revient aux paramètres enregistrés, et fermer la fenêtre avec des modifications non validées
+demande confirmation avant de les abandonner. Localisation et Affichage sont mémorisés par
+navigateur ; les tags de couleur et les sources de logs sont enregistrés sur le serveur. La purge
+et la réinitialisation des colonnes agissent immédiatement.
 
-- **Localisation**
+- **Localisation et langue**
   - *Langue* : anglais ou français.
   - *Date et heure* : fuseau horaire (celui du navigateur, UTC ou environ 80 fuseaux courants)
     et format d'affichage de l'heure de réception : `DD/MM/YYYY HH:MM:SS` (par défaut,
     l'affichage français habituel), avec millisecondes, `YYYY-MM-DD`, horloge sur 12 heures,
     ISO 8601 ou epoch Unix. Le fuseau horaire s'applique à toutes les dates affichées.
-- **Filtres** : tags de couleur. Chaque tag a un mot-clé, une couleur de fond (le texte passe
+- **Motifs de recherche** : tags de couleur. Chaque tag a un mot-clé, une couleur de fond (le texte passe
   automatiquement en noir ou en blanc pour rester lisible) et des options : mot entier, respect
   de la casse, expression régulière, actif. Les tags sont stockés sur le serveur dans
   `/data/tags.json` (volume `logstream-data`) : ils sont donc partagés par tous les navigateurs.
-  Tags par défaut (pastel) : `warning` (orange), `error` (rouge), `ok` (vert). Les tags par
+  Tags par défaut (pastel) : `warning` (orange) et `error` (rouge) ; `ok` (vert) est dans le
+  préréglage *Niveaux de log*. Les tags par
   défaut qui utilisent encore les couleurs des versions précédentes passent automatiquement aux
   couleurs pastel.
-  Le menu *+ Préréglage…* ajoute des tags tout faits pour les logs d'accès HTTP/HTTPS (nginx et
-  Apache common/combined, Traefik CLF et JSON, Caddy JSON, HAProxy httplog) : codes de statut
-  (2xx vert, 3xx bleu, 4xx orange, 5xx rouge), méthodes, sondes et attaques (`wp-login.php`,
-  `/.env`, `../`…), robots et scripts, erreurs TLS et proxy. Les tags déjà présents ne sont pas
-  ajoutés en double, et les tags ajoutés se modifient comme les autres. Dans une expression
+  Le menu *+ Préréglage…* ajoute des tags tout faits : logs d'accès HTTP/HTTPS (codes de statut,
+  méthodes, sondes, robots, erreurs TLS et proxy), logs système (SSH, sudo, noyau, systemd,
+  pare-feu), applications (Docker, bases de données) et motifs généraux (niveaux de log,
+  adresses IPv4). Les tags déjà présents ne sont pas ajoutés en double, et les tags ajoutés se
+  modifient comme les autres. La liste vient d'un fichier texte modifiable (`PRESETS_FILE`) :
+  voir [docs/presets.fr.md](docs/presets.fr.md) pour le détail de chaque préréglage et le
+  format du fichier. Dans une expression
   régulière, un groupe nommé `hl` (`(?<hl>…)`) ne colore que cette partie de la correspondance :
   les préréglages s'en servent pour colorer le code de statut ou la méthode, pas le texte autour.
   Chaque tag reçoit un code à deux chiffres (`01`, `02`…) attribué par le serveur : il reste
   attaché au tag jusqu'à sa suppression (les tags créés par les versions précédentes en reçoivent
-  un aussi). La colonne *Filtres* de la liste affiche, en badges gris, les codes des tags actifs
+  un aussi). La colonne *Motif de recherche* de la liste affiche, en badges gris, les codes des tags actifs
   trouvés dans chaque message ; elle a la place pour 3, au-delà elle en affiche 2 et `+N`, et
   l'infobulle les liste tous.
-- **Interface**
+- **Affichage**
   - *Thème* : Système (suit la préférence de l'ordinateur ou du téléphone), Clair ou Sombre. Le
     bouton soleil/lune de l'en-tête bascule entre clair et sombre.
   - *Affichage des logs* : taille du texte (très petite, petite, moyenne, grande), densité
@@ -254,11 +442,15 @@ couleur, est mémorisé par navigateur.
     européen de polices respectueux de la vie privée ; sans accès à internet, la police du
     système est utilisée. Les ligatures sont désactivées pour que `->` ou `!=` s'affichent tels
     quels. Le réglage le plus dense est Très petite + Compacte + Inconsolata Condensed.
-- **Données** : « Supprimer tous les logs » efface définitivement tous les logs stockés (il faut
+- **Base de données** : chiffres de la base lus dans VictoriaLogs (actualisés au plus toutes les 30 s) :
+  lignes stockées, taille sur disque (index compris), taille brute et taux de compression,
+  période couverte avec la rétention, lignes des dernières 24 h et de la dernière heure, hôtes
+  et applications distincts, espace disque libre. Les tailles sont en Ko/Mo/Go (KB/MB/GB en
+  anglais). « Supprimer tous les logs » efface définitivement tous les logs stockés (il faut
   taper `PURGE` pour confirmer). Les tags et les paramètres sont conservés. VictoriaLogs doit
-  être lancé avec `-delete.enable` (déjà présent dans `docker-compose.yml`) ; mettez
-  `ALLOW_PURGE=false` pour désactiver la fonction. Toute personne qui peut ouvrir l'interface
-  peut purger : activez l'[authentification](#authentification) si l'interface est accessible
+  être lancé avec `-delete.enable` (déjà présent dans `docker-compose.yml`). La fonction est
+  désactivée par défaut : mettez `ALLOW_PURGE=true` pour l'autoriser. Tout administrateur peut
+  alors purger : activez l'[authentification](#authentification) si l'interface est accessible
   à d'autres.
 
 ## Authentification
@@ -267,6 +459,7 @@ couleur, est mémorisé par navigateur.
 
 - **`local`** (par défaut) : une page de connexion avec le compte `AUTH_USER` / `AUTH_PASS` ; laissez-les
   vides pour n'avoir aucune authentification (par exemple derrière un reverse proxy qui contrôle déjà).
+  L'interface affiche alors un bandeau d'avertissement, que l'on peut fermer.
 - **`oidc`** : connexion par un fournisseur OpenID Connect (Keycloak, Authentik, Authelia, Zitadel…),
   flux « authorization code » avec PKCE.
 
@@ -277,6 +470,10 @@ déconnexion (en haut à droite) y met fin. Les échecs de connexion sont écrit
 l'adresse du client (`auth: failed login for "bob" from 192.0.2.7`). Les scripts peuvent toujours
 appeler l'API avec des identifiants HTTP Basic (`curl -u utilisateur:motdepasse`).
 
+Un **compte en lecture seule** optionnel, `AUTH_VIEWER_USER` / `AUTH_VIEWER_PASS`, peut chercher,
+suivre le direct et exporter, mais pas modifier les tags, les sources ni purger : ces réglages
+sont grisés dans son interface et l'API répond `403`.
+
 Pour afficher votre logo sur la page de connexion, montez un PNG dans le conteneur et indiquez
 son chemin dans `LOGIN_LOGO` :
 
@@ -317,6 +514,16 @@ l'application). Les connexions sont écrites dans les logs de logstream (`oidc:
 Avec une URL de retour en `https`, les cookies ne sont envoyés qu'en HTTPS : logstream doit être
 joint à travers un reverse proxy TLS.
 
+Pour donner un accès en lecture seule à certains utilisateurs, définissez `OIDC_ADMIN_GROUP` (par
+exemple `logstream-admins`) : seuls ses membres sont administrateurs, les autres sont en lecture
+seule. Les groupes sont lus dans la revendication `groups` du jeton d'identité
+(`OIDC_GROUPS_CLAIM` pour en utiliser une autre) ; dans Keycloak, ajoutez au client un mapper
+« Group Membership » (le `/` initial est ignoré).
+
+Quel que soit le mode, chaque réponse porte des en-têtes de sécurité (Content-Security-Policy,
+X-Frame-Options…), et l'API refuse les modifications envoyées depuis un autre site (requêtes
+intersites).
+
 ## Noms d'hôtes (DNS inverse)
 
 Quand un équipement envoie son adresse IP comme nom d'hôte (ou pas de nom d'hôte du tout),
@@ -339,31 +546,44 @@ résolutions.
 | `RETENTION` | `30d` | durée de conservation des logs dans VictoriaLogs |
 | `AUTH_MODE` | `local` | `local` (page de connexion) ou `oidc`, voir [Authentification](#authentification) |
 | `AUTH_USER` / `AUTH_PASS` | vide | compte de la page de connexion (mode `local`) ; vide = pas d'authentification |
+| `AUTH_VIEWER_USER` / `AUTH_VIEWER_PASS` | vide | compte optionnel en lecture seule (mode `local`) |
 | `LOGIN_LOGO` | vide | PNG affiché sur la page de connexion, chemin dans le conteneur (mode `local`) |
 | `SESSION_TTL` | `12h` | durée de la session (les deux modes ; `OIDC_SESSION_TTL` fonctionne toujours) |
 | `OIDC_ISSUER` | vide | URL de l'issuer du fournisseur OpenID Connect (mode `oidc`) |
 | `OIDC_CLIENT_ID` / `OIDC_CLIENT_SECRET` | vide | client déclaré dans le fournisseur |
 | `OIDC_REDIRECT_URL` | vide | URL de retour de logstream, ex. `https://logs.example.org/auth/callback` |
 | `OIDC_SCOPES` | `openid profile email` | scopes demandés |
+| `OIDC_ADMIN_GROUP` | vide | seuls les membres de ce groupe sont administrateurs, les autres en lecture seule (vide = tout le monde est administrateur) |
+| `OIDC_GROUPS_CLAIM` | `groups` | revendication du jeton d'identité qui liste les groupes |
 | `RDNS` | `on` | résoudre les hôtes donnés par leur IP en noms DNS |
 | `DNS_SERVER` | vide | serveur DNS pour les résolutions inverses (`ip` ou `ip:port`) |
-| `ALLOW_PURGE` | `true` | autoriser « Supprimer tous les logs » dans les Paramètres |
+| `ALLOW_PURGE` | `false` | autoriser « Supprimer tous les logs » dans les Paramètres |
+| `SYSLOG_TCP_MAX_CONNS` | `512` | connexions syslog TCP ouvertes en même temps ; au-delà, elles sont refusées |
+| `SYSLOG_TCP_IDLE` | `30m` | une connexion syslog TCP silencieuse pendant cette durée est fermée (les émetteurs se reconnectent) |
 | `EXPORT_MAX` | `100000` | nombre maximal de lignes dans un export CSV |
+| `PRESETS_FILE` | `/data/presets.json` | fichier des préréglages de tags ; liste intégrée s'il est absent (voir [docs/presets.fr.md](docs/presets.fr.md)) |
 | `DOCKER_LOGS` | `on` dans compose | collecter les logs des conteneurs Docker locaux |
 | `DOCKER_HOST` | `tcp://docker-proxy:2375` dans compose | adresse de l'API Docker (`unix:///var/run/docker.sock` hors compose) |
 | `DOCKER_BACKFILL` | `1h` | historique lu pour un conteneur vu pour la première fois |
 | `HOST_LOGS_GID` | `4` (adm) dans compose | groupe donné au conteneur pour lire les logs de l'hôte |
 | `HOST_LOGS_BACKFILL` | `1h` | historique lu à l'activation de la source « logs système de l'hôte » |
 | `HOST_LOGS_ROOT` | `/host` | emplacement de montage des répertoires de l'hôte |
+| `DMESG_BACKFILL` | `1h` | historique lu à l'activation de la source « messages du noyau » |
+| `DMESG_DEVICE` | `/dev/kmsg` | périphérique du log noyau lu par la source « messages du noyau » |
+| `AUDIT_LOG` | `/var/log/audit/audit.log` | chemin par défaut du journal d'audit Linux (modifiable dans Réglages > Sources) |
+| `AUDIT_BACKFILL` | `1h` | historique lu à l'activation de la source « audit Linux » |
+| `AUDIT_HOST` | vide | nom d'hôte des événements d'audit quand les enregistrements n'ont pas de `node=` |
+| `FILES_BACKFILL` | `1h` | historique lu à l'activation d'un fichier de logs (Paramètres > Sources de logs > Fichiers de logs) |
 | `TZ` | `Europe/Paris` | fuseau horaire des horodatages RFC 3164 (qui n'en portent pas) |
 | `BATCH_SIZE`, `FLUSH_MS`, `QUEUE_SIZE` | `1000`, `1000`, `100000` | réglage de l'ingestion |
+| `SPOOL_MAX_MB` | `1024` | taille du tampon disque des lots refusés par VictoriaLogs (`0` = pas de tampon : 15 s de tentatives, puis perte) |
 
 ## Débogage
 
 - `docker compose logs -f logstream` : erreurs de réception et erreurs d'envoi vers
   VictoriaLogs.
-- La barre du bas affiche les compteurs reçus / stockés / perdus et la dernière erreur de
-  stockage.
+- La barre du bas affiche les compteurs reçus / stockés / perdus, les messages en attente dans
+  le tampon disque et la dernière erreur de stockage.
 - <http://localhost:9428/select/vmui> : l'interface de VictoriaLogs, pour essayer des requêtes
   LogsQL.
 - API :
@@ -394,7 +614,7 @@ Pour mettre à jour l'une d'elles :
    VictoriaLogs conserve son format de stockage entre versions mineures ; lisez le changelog
    avant un changement de version majeure.
 2. Modifiez la version dans le fichier indiqué ci-dessus, puis lancez `docker compose up -d --build`.
-3. Vérifiez la barre du bas (reçus / stockés / perdus) et **Paramètres > Sources**. Pour revenir
+3. Vérifiez la barre du bas (reçus / stockés / perdus) et **Paramètres > Sources de logs**. Pour revenir
    en arrière, remettez la version précédente et lancez la même commande.
 
 ## Organisation du code
@@ -412,9 +632,14 @@ Pour mettre à jour l'une d'elles :
 | `rdns.go` | résolutions DNS inverses avec cache |
 | `export.go` | export CSV en flux |
 | `docker.go` | logs des conteneurs Docker (API, lecteurs, positions, détection du niveau) |
-| `syslogserver.go` | écoutes syslog ouvertes et fermées depuis Paramètres > Sources |
+| `syslogserver.go` | écoutes syslog ouvertes et fermées depuis Paramètres > Sources de logs |
 | `hostlogs.go`, `journal.go` | logs système de l'hôte : lecteur du journal systemd (sans `journalctl`) et suivi de `/var/log` |
+| `dmesg.go` | messages du noyau : lecture de `/dev/kmsg`, analyse des enregistrements, position par identifiant de démarrage et numéro de séquence |
+| `audit.go` | audit Linux : suivi de `audit.log` (rotation, position enregistrée), analyse des enregistrements, regroupement par événement, résumé |
+| `filesource.go`, `fileformats.go` | fichiers de logs : suivi (rotation, positions enregistrées, lignes de suite) et formats (détection, texte, JSON, logfmt, CLF, Traefik, expression régulière) |
+| `selflog.go` | logs internes de LogStream : `logEvent`, niveau minimal, limitation des répétitions, file bornée |
 | `tags.go` | stockage des tags de couleur |
+| `presets.go`, `presets.json` | préréglages de tags (`/api/presets`), liste intégrée |
 | `api.go` | routes HTTP `/api/*` |
 | `web/` | interface (HTML, CSS, JavaScript simple, sans étape de build), embarquée dans le binaire ; les traductions sont dans `web/app.js` (`I18N`), et dans `web/login.html` pour la page de connexion |
 

README.md

@@ -17,7 +17,9 @@ devices ──514 udp/tcp──▶ logstream (Go) ──HTTP batches──▶ Vi
 ![Schéma logique de Logstream](docs/architecture.png)
 
 - **Ingestion**: syslog (UDP/TCP) and Docker container logs both go through `sink()` (reverse DNS
-  on IP hosts), then the `Store` queue, which sends them in batches to VictoriaLogs.
+  on IP hosts, without holding up the listeners), then the `Store` queue, which sends them in
+  batches to VictoriaLogs. When VictoriaLogs is unreachable, batches are kept on disk
+  (`/data/spool`, up to `SPOOL_MAX_MB`) and sent again, oldest first, once it is back.
 - **Live view**: `sink()` also publishes each message to the `Hub`, which streams it to the
   browsers over SSE.
 - **Search**: the HTTP API turns the UI filters into LogsQL queries sent to VictoriaLogs.
@@ -48,7 +50,7 @@ Then open <http://localhost:8080>.
 - **Manual test**: `logger -n 127.0.0.1 -P 514 -d "hello error"` (util-linux) or
   `echo "<14>test ok" | nc -u -w1 127.0.0.1 514`.
 
-**Settings > Sources > Syslog** turns syslog reception on or off and chooses the protocols
+**Settings > Log sources > Syslog** turns syslog reception on or off and chooses the protocols
 (UDP, TCP) without restarting; the choice is saved in `/data/syslog.json`. It also shows the
 listening state (and the error if the port is already in use). The port itself is published
 by docker-compose: change `SYSLOG_PORT` in `.env`, then run `docker compose up -d`.
@@ -81,28 +83,41 @@ versions before this change are indexed by their message timestamp; purge them f
 Settings to start clean.
 
 Severity badges `err`/`crit` and `warning` use the colors of the `error` and `warning` tags.
+Each row starts with a fixed-width badge naming its source, one color per source: **SYSLOG**,
+**DOCKER**, **KERNEL** (dmesg), **HOST** (files of `/var/log`), **AUDIT**, **FILE** and **LS**
+(LogStream's own logs).
 
 Shortcuts: `/` focuses the search box, `Esc` clears it. Clicking a row shows all its fields.
 
 The column headers stay visible while scrolling. Drag the edge of a header (received, message
 time, severity, host, app) to resize the column, double-click it to go back to the automatic
 width; the message takes the remaining space. Widths are remembered by the browser
-(**Settings > Interface > Reset column widths** restores them all). On phones the list keeps its
+(**Settings > Appearance > Reset column widths** restores them all). On phones the list keeps its
 two-line layout without columns.
 
+## Stream and Time range modes
+
+The first control of the filter bar switches between two display modes:
+
+- **Stream**: the latest logs over a sliding duration (5 min to 30 days, or all), with the live
+  view.
+- **Time range**: the logs between a start and an end date, typed in the time zone chosen in
+  Settings. ◀ and ▶ move to the previous or next range of the same length, the magnifier doubles
+  it around its middle. The live view pauses; the mode and the range are kept across reloads.
+
 ## Timeline
 
 The timeline above the list shows the volume of logs per interval, counted by **reception
 time** on the server clock (so it matches the times shown in the rows).
 
 - Hover an interval: its bounds, total and detail per severity.
-- Click a bar to zoom on that interval, or drag across several bars to zoom on the selection.
-  The time range then shows the zoomed period ("× Reset zoom" or any other range leaves it);
-  the list, the counters and the CSV export follow the zoom, and the live view pauses.
+- Click a bar to show that interval in Time range mode, or drag across several bars to show the
+  selection; "× Back to stream" returns to Stream mode. The list, the counters and the CSV export
+  follow the range.
 - In live mode the last interval grows as messages arrive, and the timeline reloads at each new
   interval. Nothing is refreshed while the browser tab is hidden; it catches up when shown again.
 
-**Settings > Interface > Timeline** (remembered per browser): scale (linear, √ by default, log),
+**Settings > Appearance > Timeline** (remembered per browser): scale (linear, √ by default, log),
 height (S/M/L: 40/80/120 px), color (stacked by severity, intensity compared with the median of
 the window: calm, burst above 3×, anomaly above 10×, or none), bars or area, division
 (automatic, about 100 intervals, or fixed: 1 s, 10 s, 1 min, 5 min, 1 h, 1 day) and refresh
@@ -129,7 +144,7 @@ colored and exported like syslog messages:
 - The severity comes from the line itself when the application writes it: JSON
   (`"level":"error"`), logfmt (`level=warn`), `[ERROR]`, or an upper-case level word at the
   start of the line (`ERROR`, `WARN`…). Otherwise it is `info`. Terminal color codes are removed.
-- **Settings > Sources** shows one label per container (`project/service`) in a single field:
+- **Settings > Log sources** shows one label per container (`project/service`) in a single field:
   followed containers in color, then not followed ones in grey; a click switches a label.
   The color identifies the compose project, and Docker app names in the log list use the
   same color. Stopped containers are hidden by default ("Show stopped containers" displays
@@ -137,8 +152,10 @@ colored and exported like syslog messages:
   to the labels shown) help with many containers. New containers are followed automatically
   unless that option is turned off. Choices are saved per compose service (or container name)
   in `/data/docker.json`, so they survive re-creations.
-- Logstream remembers the position read in each container (`/data/docker-state.json`): after a
-  restart it resumes without losing or duplicating lines. A container seen for the first time
+- Logstream remembers the position of the last line stored for each container
+  (`/data/docker-state.json`): after a restart it resumes without losing lines. The position
+  only moves once a line is in VictoriaLogs or in the disk buffer, and a full queue slows the
+  reading down instead of dropping lines. A container seen for the first time
   is read from `DOCKER_BACKFILL` ago (1 hour by default).
 - Logstream itself and the proxy below are never collected; add the label
   `logstream.exclude=true` to any other container to exclude it for good.
@@ -151,7 +168,7 @@ which only lets through listing containers, reading logs, events and engine info
 
 Logstream can also collect the system logs of the machine hosting the stack, without
 configuring anything on the host. The source is **off by default**: turn it on in
-**Settings > Sources > Host system logs** (saved in `/data/hostlogs.json`).
+**Settings > Log sources > Host system logs** (saved in `/data/hostlogs.json`).
 
 - `docker-compose.yml` mounts `/var/log` and `/run/log/journal` read-only under `/host`.
 - When the host runs systemd, Logstream reads the **systemd journal** files directly (no
@@ -166,13 +183,160 @@ configuring anything on the host. The source is **off by default**: turn it on i
 - **Permissions**: the container runs as an unprivileged user and gets the `adm` group
   (gid 4), which can read the journal and `/var/log` on Debian and Ubuntu. On other systems,
   set `HOST_LOGS_GID` in `.env` to the gid of `systemd-journal`
-  (`getent group systemd-journal | cut -d: -f3`). Settings > Sources shows a clear message when
+  (`getent group systemd-journal | cut -d: -f3`). Settings > Log sources shows a clear message when
   access is denied.
 - Limits: journal fields compressed by journald (messages longer than 512 bytes, compressed
   with zstd/lz4/xz) cannot be decoded without extra libraries; they are counted in Settings and
   shown as "(compressed journal entry)". Rotated or compressed text files (`*.1`, `*.gz`) are
   not read.
 
+## Kernel messages (dmesg)
+
+Logstream can collect the kernel ring buffer of the host (what `dmesg` shows: hardware,
+drivers, OOM killer, firewall…) by reading `/dev/kmsg`. The source is **off by default**: turn it
+on in **Settings > Log sources > Kernel messages (dmesg)** (saved in `/data/dmesg.json`).
+
+- **Device**: the container does not see `/dev/kmsg` by default. Uncomment the `devices`
+  section of `docker-compose.yml` (`/dev/kmsg:/dev/kmsg:r`, read-only), then
+  `docker compose up -d`.
+- **Permissions**: when the host has `kernel.dmesg_restrict=1` (the default on Debian and
+  Ubuntu), only processes with the `CAP_SYSLOG` capability can read the kernel log, and the
+  container runs as an unprivileged user. Either:
+  - allow it on the host: `sysctl -w kernel.dmesg_restrict=0`, kept across reboots with
+    `echo kernel.dmesg_restrict=0 | sudo tee /etc/sysctl.d/50-dmesg.conf` (every user of the
+    host can then run `dmesg`); this setting cannot be changed from a container;
+  - or run Logstream as root with the `SYSLOG` capability: uncomment `user: "0:0"` and
+    `cap_add: [SYSLOG]` in `docker-compose.yml`.
+
+  Settings > Log sources says when the device is missing or access is denied; the rest of
+  Logstream keeps working and the device is tried again every 10 seconds.
+- **Fields**: **app** is `kernel` (or the program name for messages written by programs such
+  as `systemd[1]: …`), severity and facility come from the record, **host** is `localhost`,
+  `subsystem` and `device` are kept when the kernel gives them. These logs have the `kernel`
+  source (`proto` `kmsg`): the **Source** filter shows them alone.
+- **Time**: records carry the time since boot; Logstream turns it into a date using the boot
+  time (`/proc/uptime`). As with `dmesg -T`, the time can be early after the host was suspended.
+- When the source is turned on, the last hour is read first (`DMESG_BACKFILL`, `0` = only new
+  messages). The sequence number of the last message and the boot ID are saved in
+  `/data/dmesg-state.json`: after a restart of Logstream, reading resumes after the last
+  message (no duplicates); after a reboot of the host, the new buffer is read from
+  `DMESG_BACKFILL` ago. Messages overwritten in the kernel buffer before being read are counted
+  in Settings.
+
+## Linux audit (auditd)
+
+Logstream can follow the log of the Linux audit daemon (`/var/log/audit/audit.log`): logins,
+`sudo`, watched files, syscalls matched by your `auditctl` rules… The source is **off by
+default**: turn it on in **Settings > Log sources > Linux audit (auditd)**, where the file path can
+also be changed (saved in `/data/audit.json`; `AUDIT_LOG` sets the default path).
+
+- **Mount**: uncomment `/var/log/audit:/var/log/audit:ro` in `docker-compose.yml`, then
+  `docker compose up -d`. (`/var/log` is already mounted under `/host` for the host system
+  logs, so `/host/var/log/audit/audit.log` also works as the path, without a new volume.)
+- **Permissions** (host side): auditd writes its log as `root`, mode `0600`, in a `0700`
+  directory, and Logstream runs as UID `10001`. The reliable way is the group the container
+  already gets for the host logs (`HOST_LOGS_GID`, `adm` by default):
+  ```bash
+  sudo sed -i 's/^log_group.*/log_group = adm/' /etc/audit/auditd.conf
+  sudo chgrp adm /var/log/audit && sudo chmod 750 /var/log/audit
+  sudo service auditd restart        # systemctl refuses to restart auditd on some distributions
+  ```
+  auditd then creates every rotated file with mode `0640` and group `adm`. An ACL also works
+  (`sudo setfacl -m u:10001:rx /var/log/audit && sudo setfacl -m u:10001:r /var/log/audit/audit.log`)
+  but must be applied again to each new file after a rotation. Settings > Log sources says when the
+  file is missing or access is denied; it is tried again every second.
+- **Events**: the records of one event (`SYSCALL`, `EXECVE`, `CWD`, `PATH`, `PROCTITLE`…) share
+  the same `msg=audit(time:serial)` and become **one** log, once no record came for 2 seconds.
+  The message is a summary — who, what, result — such as
+  `cedric (as root): exec apt install nginx [exec] → success` or
+  `bob: PAM:authentication via /usr/sbin/sshd from 203.0.113.9 on ssh → failed`; the raw
+  records are kept in `audit_raw` and shown under the summary (folded in compact density until
+  the line is opened). Hexadecimal values (`proctitle`, `cmd`, arguments with spaces) are
+  decoded.
+- **Fields**: `audit_type` (type of the first record, also used as **app**), `audit_serial`,
+  `auid` (login user ID), `user` (its name, or the uid when it cannot be resolved), `exe`, `res`
+  (`success` / `failed`, from `res=` or `success=`) and `key` (rule key). Severity is `warning`
+  when the result is a failure, `info` otherwise; facility `authpriv`; source `audit`. In the
+  list, audit lines have a violet left edge, a light tint and the **AUDIT** source badge;
+  the **Source** filter shows them alone.
+- **Names**: `user` comes from the enriched format (`log_format = ENRICHED`, the default of
+  recent auditd versions), else from the host's `/etc/passwd` when it is mounted as
+  `/host/etc/passwd`. **host** is the `node=` of the records (`name_format = hostname` in
+  `auditd.conf`), else `AUDIT_HOST`, else `/host/etc/hostname`, else `localhost`.
+- When the source is turned on, the last hour is read first (`AUDIT_BACKFILL`, `0` = only new
+  events). The inode and an offset before which every event was sent are saved in
+  `/data/audit-state.json`: after a restart, reading resumes there; after a rotation by auditd,
+  the end of `audit.log.1` is read before the new file.
+
+## Log files (Traefik, nginx, applications…)
+
+Logstream can follow the log files of other programs: Traefik, nginx, Apache, or any application
+that writes to a file. Declare each file in **Settings > Log sources > Log files** (saved in
+`/data/files.json`, up to 50): a **name** (the **app** of its entries, by default the file name),
+the **path** of the file as mounted in the container, a **format** (*Automatic* by default), an
+optional **host** (default: `/host/etc/hostname`, else `localhost`) and a switch.
+
+- **Mount** the directory read-only, e.g. in `docker-compose.yml`:
+  `- /var/log/traefik:/logs/traefik:ro`, then `docker compose up -d`. Files under `/var/log`
+  are already reachable as `/host/var/log/…`. The files must be readable by UID `10001` or the
+  group of `HOST_LOGS_GID` (`adm` by default); Settings > Log sources says when no file matches
+  or access is denied.
+- **Path**: one file, e.g. `/logs/traefik/access.log` (no wildcards). As soon as it is typed, the
+  file is checked: found or not, readable or not, its detected format and its last line.
+- **Format detection** (*Automatic*): from the last lines of the file (50 at most), the
+  structured format that at least 80 % of them follow — Traefik access JSON, JSON lines, access
+  log CLF, logfmt — else plain text. It is done again when the format is changed; the format
+  found is shown in the status of the file. Choose another format to force it (a regular
+  expression is never detected).
+- **Formats**:
+  - *Plain text*: one entry per line; the level is detected as for Docker logs, a timestamp at
+    the start of the line (ISO 8601, `2006/01/02 15:04:05`, `[02/Jan/2006:15:04:05 +0200]`,
+    `Jan  2 15:04:05`) becomes the message time and is removed from the message. Indented
+    lines (stack traces) are added to the previous entry.
+  - *JSON lines*: `msg` / `message`, `time` / `ts` / `@timestamp` (text or Unix time) and
+    `level` (word or number, pino/bunyan included) are recognized; the other keys become
+    fields, nested objects with dotted names (`req.id`).
+  - *logfmt*: `key=value` pairs, as in Traefik's default logs or Go programs; same keys as JSON.
+  - *Access log (CLF)*: Common / Combined Log Format of nginx and Apache, and Traefik's access
+    log in this format (router, server URL and duration included). Fields `client_ip`,
+    `http_method`, `http_path`, `http_status`, `http_size`, `user_agent`, `http_referer`,
+    `router`, `backend`, `duration_ms`.
+  - *Traefik access (JSON)*: the JSON access log of Traefik (`accessLog.format: json`),
+    summarized as `GET app.example.com/ 200 · 12.5 ms · app@docker · 203.0.113.9`, every key in
+    the fields. Traefik's own logs in the same file are read as JSON lines.
+  - *Regular expression* (RE2 / Go syntax): the named groups `time`, `level`, `msg`, `host`
+    and `app` fill these fields, `status` gives the level of an access log, the other groups
+    become fields, e.g. `^(?P<time>\S+ \S+) \[(?P<level>\w+)\] (?P<module>\S+): (?P<msg>.*)$`.
+    A line that does not match is added to the previous entry.
+
+  For access logs, 5xx statuses are `err`, 4xx `warning`, the others `info`. A line that does
+  not fit the chosen format is kept as plain text. Fields named like LogStream's own ones
+  (`host`, `app`…) are renamed `field_host`, `field_app`…
+- **Display**: source `file`, the path in `log_file`. In the list these lines have a green left
+  edge, a light tint and the **FILE** source badge; the **Source** filter shows them alone.
+- When a file is turned on, the lines of the last hour already in it are read first
+  (`FILES_BACKFILL`, `0` = only new lines; lines without a timestamp are then left out). The
+  start of that hour is found by bisection on the dates of the lines, so a large file that holds
+  months of logs is not read from its start; a file created later is read from its start, up to
+  64 MB per second, the status showing what is left to read. The inode and an offset are saved per file in
+  `/data/files-state.json`: after a restart reading resumes there; after a rotation
+  (`access.log` renamed `access.log.1`), the end of the old file is read before the new one;
+  a file truncated in place (`copytruncate`) is read again from its start.
+
+## LogStream internal logs
+
+Logstream records its own events as logs, with **host** `logstream`, **app** the component
+(`store`, `syslog`, `docker`, `host`, `dmesg`, `audit`, `files`, `main`) and the `logstream` source:
+VictoriaLogs unreachable and back, lost batches, batches refused from the disk buffer, syslog
+listener errors, Docker API or container streams lost, sources that cannot read, start and
+stop. They are on by default from level **warning**; **Settings > Log sources > LogStream internal
+logs** turns them off or changes the minimum level (saved in `/data/selflog.json`). The same
+event (component and message) is recorded at most once every 30 seconds, with the number of
+repeats left out; events go through a bounded queue and never wait for the storage, so an
+unreachable VictoriaLogs cannot make them pile up or loop. Everything still goes to
+`docker compose logs logstream` as before. In the list, these lines have a turquoise left edge
+and an **LS** badge before the app; the **Source** filter shows them alone.
+
 ## CSV export
 
 The **Export** button (next to the log count) downloads every stored log matching the
@@ -192,8 +356,11 @@ From the command line: `curl -o logs.csv 'localhost:8080/api/export.csv?q=error&
 
 ## Settings
 
-The gear icon opens the settings, organized in tabs. Everything except color tags is
-remembered per browser.
+The gear icon opens the settings, organized in tabs. Changes show at once but are only kept
+with the **Save** button, under the tab labels: it takes the accent color while changes are
+waiting. **Cancel** goes back to the saved settings, and closing the window with unsaved changes
+asks before dropping them. Localization and Appearance are remembered per browser; color tags
+and log sources are saved on the server. Purging and resetting column widths act at once.
 
 - **Localization**
   - *Language*: English or French.
@@ -201,25 +368,27 @@ remembered per browser.
     format of the reception time: `DD/MM/YYYY HH:MM:SS` (default, the usual French display),
     with milliseconds, `YYYY-MM-DD`, 12-hour clock, ISO 8601 or Unix epoch. The time zone
     applies to every date shown.
-- **Filters**: color tags. Each tag has a keyword, a background color (the text automatically
+- **Patterns**: color tags. Each tag has a keyword, a background color (the text automatically
   switches to black or white to stay readable) and options: whole word, match case,
   regular expression, active. Tags are stored on the server in `/data/tags.json`
   (`logstream-data` volume), so they are shared by every browser. Default tags (pastel):
-  `warning` (orange), `error` (red), `ok` (green). Default tags still using the colors of
-  earlier versions are switched to the pastel ones automatically.
-  The *+ Preset…* menu adds ready-made tags for HTTP/HTTPS access logs (nginx and Apache
-  common/combined, Traefik CLF and JSON, Caddy JSON, HAProxy httplog): status codes (2xx green,
-  3xx blue, 4xx orange, 5xx red), methods, probes and attacks (`wp-login.php`, `/.env`,
-  `../`…), bots and scripts, TLS and proxy errors. Tags already in the list are skipped, and the
-  added tags can be edited like any other. In a regular expression, a group named `hl`
+  `warning` (orange) and `error` (red); `ok` (green) is in the *Log levels* preset. Default
+  tags still using the colors of earlier versions are switched to the pastel ones
+  automatically.
+  The *+ Preset…* menu adds ready-made tags: HTTP/HTTPS access logs (status codes, methods,
+  probes, bots, TLS and proxy errors), system logs (SSH, sudo, kernel, systemd, firewall),
+  applications (Docker, databases) and general patterns (log levels, IPv4 addresses). Tags
+  already in the list are skipped, and the added tags can be edited like any other. The list
+  comes from a text file you can edit (`PRESETS_FILE`): see [docs/presets.md](docs/presets.md)
+  for each preset and the file format. In a regular expression, a group named `hl`
   (`(?<hl>…)`) colors only that part of the match: the presets use it to color the status code
   or the method, not the text around it.
   Each tag gets a two-digit code (`01`, `02`…) assigned by the server: it stays with the tag
   until the tag is deleted (codes are also given to tags created by earlier versions). The
-  *Filters* column of the log list shows, as grey badges, the codes of the active tags found in
+  *Pattern* column of the log list shows, as grey badges, the codes of the active tags found in
   each message; it has room for 3, beyond that it shows 2 and `+N`, and the tooltip lists them
   all.
-- **Interface**
+- **Appearance**
   - *Theme*: System (follows the computer/phone preference), Light or Dark. The sun/moon
     button in the header switches between light and dark.
   - *Log display*: font size (tiny, small, medium, large), density (normal, or compact to
@@ -231,10 +400,13 @@ remembered per browser.
     [Bunny Fonts](https://fonts.bunny.net), a privacy-friendly European font service; without
     internet access, the system font is used. Ligatures are disabled so `->` or `!=` show as
     typed. The densest setting is Tiny + Compact + Inconsolata Condensed.
-- **Data**: "Delete all logs" permanently erases every stored log (you must type
+- **Database**: database figures read from VictoriaLogs (refreshed at most every 30 s): stored
+  lines, size on disk (index included), raw size and compression ratio, period covered with
+  the retention, lines of the last 24 h and last hour, distinct hosts and apps, free disk
+  space. Sizes use KB/MB/GB (Ko/Mo/Go in French). "Delete all logs" permanently erases every stored log (you must type
   `PURGE` to confirm). Tags and settings are kept. VictoriaLogs needs `-delete.enable`
-  (already set in `docker-compose.yml`); set `ALLOW_PURGE=false` to disable the feature.
-  Anyone who can open the UI can purge: turn on [authentication](#authentication) if the UI
+  (already set in `docker-compose.yml`). The feature is off by default: set `ALLOW_PURGE=true`
+  to allow it. Any admin can then purge: turn on [authentication](#authentication) if the UI
   is reachable by others.
 
 ## Authentication
@@ -242,7 +414,8 @@ remembered per browser.
 `AUTH_MODE` picks how the UI and the API are protected (`/healthz` always stays open):
 
 - **`local`** (default): a login page with the account `AUTH_USER` / `AUTH_PASS`; leave them
-  empty to have no authentication (for instance behind a reverse proxy that already checks).
+  empty to have no authentication (for instance behind a reverse proxy that already checks). The
+  UI then shows a warning banner, which can be closed.
 - **`oidc`**: login through an OpenID Connect provider (Keycloak, Authentik, Authelia, Zitadel…),
   authorization code flow with PKCE.
 
@@ -252,6 +425,10 @@ ends when `AUTH_USER` or `AUTH_PASS` changes; the log out button (top right) end
 are written in the logs with the client address (`auth: failed login for "bob" from 192.0.2.7`).
 Scripts can still call the API with HTTP Basic credentials (`curl -u user:pass`).
 
+An optional **read-only account**, `AUTH_VIEWER_USER` / `AUTH_VIEWER_PASS`, can search, follow
+the live view and export, but cannot change tags, sources or purge: those settings are greyed
+out in its UI and the API answers `403`.
+
 To show your logo on the login page, mount a PNG in the container and point `LOGIN_LOGO` to it:
 
 ```yaml
@@ -289,6 +466,14 @@ Every user the provider accepts for this client can log in: restrict access in t
 in the logstream logs (`oidc: alice logged in`). With an `https` redirect URL, the cookies are
 only sent over HTTPS: logstream must be reached through a TLS reverse proxy.
 
+To give read-only access to some users, set `OIDC_ADMIN_GROUP` (for instance
+`logstream-admins`): only its members are admins, the others are read-only. The groups are read
+from the `groups` claim of the ID token (`OIDC_GROUPS_CLAIM` to use another one); in Keycloak,
+add a "Group Membership" mapper to the client (a leading `/` is ignored).
+
+Whatever the mode, every answer carries security headers (Content-Security-Policy,
+X-Frame-Options…), and the API refuses changes sent from another site (cross-site requests).
+
 ## Host names (reverse DNS)
 
 When a device sends its IP address as host name (or no host name at all), Logstream looks up
@@ -309,29 +494,43 @@ are only known by your router or a local DNS (Pi-hole, AdGuard, Unbound…), set
 | `RETENTION` | `30d` | how long VictoriaLogs keeps logs |
 | `AUTH_MODE` | `local` | `local` (login page) or `oidc`, see [Authentication](#authentication) |
 | `AUTH_USER` / `AUTH_PASS` | empty | account of the login page (`local` mode); empty = no authentication |
+| `AUTH_VIEWER_USER` / `AUTH_VIEWER_PASS` | empty | optional read-only account (`local` mode) |
 | `LOGIN_LOGO` | empty | PNG shown on the login page, path inside the container (`local` mode) |
 | `SESSION_TTL` | `12h` | session lifetime (both modes; `OIDC_SESSION_TTL` still works) |
 | `OIDC_ISSUER` | empty | issuer URL of the OpenID Connect provider (`oidc` mode) |
 | `OIDC_CLIENT_ID` / `OIDC_CLIENT_SECRET` | empty | client registered in the provider |
 | `OIDC_REDIRECT_URL` | empty | callback URL of logstream, e.g. `https://logs.example.org/auth/callback` |
 | `OIDC_SCOPES` | `openid profile email` | requested scopes |
+| `OIDC_ADMIN_GROUP` | empty | only members of this group are admins, the others read-only (empty = everyone is admin) |
+| `OIDC_GROUPS_CLAIM` | `groups` | ID token claim that lists the groups |
 | `RDNS` | `on` | resolve IP hosts to DNS names |
 | `DNS_SERVER` | empty | DNS server for reverse lookups (`ip` or `ip:port`) |
-| `ALLOW_PURGE` | `true` | allow "Delete all logs" in Settings |
+| `ALLOW_PURGE` | `false` | allow "Delete all logs" in Settings |
+| `SYSLOG_TCP_MAX_CONNS` | `512` | syslog TCP connections open at once; more are refused |
+| `SYSLOG_TCP_IDLE` | `30m` | a syslog TCP connection silent this long is closed (senders reconnect) |
 | `EXPORT_MAX` | `100000` | maximum number of rows in a CSV export |
+| `PRESETS_FILE` | `/data/presets.json` | color tag presets file; the built-in list when missing (see [docs/presets.md](docs/presets.md)) |
 | `DOCKER_LOGS` | `on` in compose | collect the logs of the local Docker containers |
 | `DOCKER_HOST` | `tcp://docker-proxy:2375` in compose | Docker API address (`unix:///var/run/docker.sock` outside compose) |
 | `DOCKER_BACKFILL` | `1h` | history read from a container seen for the first time |
 | `HOST_LOGS_GID` | `4` (adm) in compose | group given to the container to read the host logs |
 | `HOST_LOGS_BACKFILL` | `1h` | history read when the host system logs source is turned on |
 | `HOST_LOGS_ROOT` | `/host` | where the host directories are mounted |
+| `DMESG_BACKFILL` | `1h` | history read when the kernel messages source is turned on |
+| `DMESG_DEVICE` | `/dev/kmsg` | kernel log device read by the kernel messages source |
+| `AUDIT_LOG` | `/var/log/audit/audit.log` | default path of the Linux audit log (can be changed in Settings > Log sources) |
+| `AUDIT_BACKFILL` | `1h` | history read when the Linux audit source is turned on |
+| `AUDIT_HOST` | empty | host name of the audit events when the records carry no `node=` |
+| `FILES_BACKFILL` | `1h` | history read when a log file is turned on (Settings > Log sources > Log files) |
 | `TZ` | `Europe/Paris` | time zone for RFC 3164 timestamps (which carry none) |
 | `BATCH_SIZE`, `FLUSH_MS`, `QUEUE_SIZE` | `1000`, `1000`, `100000` | ingestion tuning |
+| `SPOOL_MAX_MB` | `1024` | disk buffer size for batches VictoriaLogs could not take (`0` = no buffer: retried for 15 s, then dropped) |
 
 ## Debugging
 
 - `docker compose logs -f logstream`: receive errors and errors sending to VictoriaLogs.
-- The bottom bar shows received / stored / dropped counters and the last storage error.
+- The bottom bar shows received / stored / dropped counters, the messages waiting in the disk
+  buffer, and the last storage error.
 - <http://localhost:9428/select/vmui>: VictoriaLogs' own UI to try LogsQL queries.
 - API:
   ```bash
@@ -361,7 +560,7 @@ To update one of them:
    VictoriaLogs keeps its storage format across minor versions; read the changelog before a
    major version change.
 2. Change the version in the file above, then run `docker compose up -d --build`.
-3. Check the bottom bar (received / stored / dropped) and **Settings > Sources**. To go back,
+3. Check the bottom bar (received / stored / dropped) and **Settings > Log sources**. To go back,
    restore the previous version and run the same command.
 
 ## Code layout
@@ -379,9 +578,14 @@ To update one of them:
 | `rdns.go` | cached reverse DNS lookups |
 | `export.go` | streamed CSV export |
 | `docker.go` | Docker container logs (API, followers, positions, level detection) |
-| `syslogserver.go` | syslog listeners opened and closed from Settings > Sources |
+| `syslogserver.go` | syslog listeners opened and closed from Settings > Log sources |
 | `hostlogs.go`, `journal.go` | host system logs: systemd journal reader (no `journalctl`) and `/var/log` follower |
+| `dmesg.go` | kernel messages: `/dev/kmsg` reader, record parsing, position by boot ID and sequence number |
+| `audit.go` | Linux audit: `audit.log` follower (rotation, saved offset), record parsing, grouping by event, summary |
+| `filesource.go`, `fileformats.go` | log files: follower (rotation, saved offsets, continuation lines) and formats (detection, text, JSON, logfmt, CLF, Traefik, regular expression) |
+| `selflog.go` | LogStream internal logs: `logEvent`, minimum level, throttling, bounded queue |
 | `tags.go` | color tag storage |
+| `presets.go`, `presets.json` | color tag presets (`/api/presets`), built-in list |
 | `api.go` | `/api/*` HTTP routes |
 | `web/` | UI (HTML, CSS, plain JavaScript, no build step), embedded in the binary; translations live in `web/app.js` (`I18N`), and in `web/login.html` for the login page |
 

api.go

@@ -16,12 +16,18 @@ type API struct {
 	store      *Store
 	hub        *Hub
 	tags       *TagStore
+	presets    string // presets file, built-in presets when missing
 	rdns       *ReverseDNS
 	allowPurge bool
 	exportMax  int
 	docker     *DockerManager // nil when DOCKER_LOGS is off
 	syslog     *SyslogServer
 	host       *HostLogs
+	dmesg      *Dmesg
+	audit      *Audit
+	files      *Files
+	selfLog    *SelfLog
+	dbstats    dbStatsCache
 }
 
 func (a *API) Routes(mux *http.ServeMux) {
@@ -31,9 +37,13 @@ func (a *API) Routes(mux *http.ServeMux) {
 	mux.HandleFunc("GET /api/facets", a.facets)
 	mux.HandleFunc("GET /api/stream", a.stream)
 	mux.HandleFunc("GET /api/stats", a.stats)
+	mux.HandleFunc("GET /api/dbstats", a.dbStats)
 	mux.HandleFunc("GET /api/tags", a.listTags)
 	mux.HandleFunc("POST /api/tags", a.createTag)
+	mux.HandleFunc("PUT /api/tags", a.replaceTags)
+	mux.HandleFunc("GET /api/tags/defaults", a.defaultTags)
 	mux.HandleFunc("POST /api/tags/reset", a.resetTags)
+	mux.HandleFunc("GET /api/presets", a.listPresets)
 	mux.HandleFunc("PUT /api/tags/{id}", a.updateTag)
 	mux.HandleFunc("DELETE /api/tags/{id}", a.deleteTag)
 	mux.HandleFunc("GET /api/purge", a.purgeStatus)
@@ -45,6 +55,110 @@ func (a *API) Routes(mux *http.ServeMux) {
 	mux.HandleFunc("PUT /api/docker", a.dockerConfigure)
 	mux.HandleFunc("GET /api/hostlogs", a.hostLogsStatus)
 	mux.HandleFunc("PUT /api/hostlogs", a.hostLogsConfigure)
+	mux.HandleFunc("GET /api/dmesg", a.dmesgStatus)
+	mux.HandleFunc("PUT /api/dmesg", a.dmesgConfigure)
+	mux.HandleFunc("GET /api/audit", a.auditStatus)
+	mux.HandleFunc("PUT /api/audit", a.auditConfigure)
+	mux.HandleFunc("GET /api/files", a.filesStatus)
+	mux.HandleFunc("PUT /api/files", a.filesConfigure)
+	mux.HandleFunc("POST /api/files/detect", a.filesDetect)
+	mux.HandleFunc("GET /api/selflog", a.selfLogStatus)
+	mux.HandleFunc("PUT /api/selflog", a.selfLogConfigure)
+}
+
+// GET /api/audit: state of the Linux audit source (Settings > Sources).
+func (a *API) auditStatus(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, a.audit.Status())
+}
+
+// PUT /api/audit {"enabled": bool, "path": "/var/log/audit/audit.log"}
+func (a *API) auditConfigure(w http.ResponseWriter, r *http.Request) {
+	var cfg auditConfig
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&cfg); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	if err := a.audit.Configure(cfg); err != nil {
+		writeErr(w, http.StatusInternalServerError, err)
+		return
+	}
+	log.Printf("audit source changed from %s: %+v", r.RemoteAddr, cfg)
+	writeJSON(w, http.StatusOK, a.audit.Status())
+}
+
+// GET /api/files: the log files of the "Files" source (Settings > Sources).
+func (a *API) filesStatus(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, a.files.Status())
+}
+
+// PUT /api/files {"sources": [{"id", "name", "path", "format" (auto or a format), "regex", "host", "enabled"}]}
+// (no id: a new file).
+func (a *API) filesConfigure(w http.ResponseWriter, r *http.Request) {
+	var cfg filesConfig
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 64<<10)).Decode(&cfg); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	if err := a.files.Configure(cfg); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	log.Printf("file sources changed from %s: %d files", r.RemoteAddr, len(cfg.Sources))
+	writeJSON(w, http.StatusOK, a.files.Status())
+}
+
+// POST /api/files/detect {"path": "/logs/traefik/access.log"}: whether the file
+// can be read, its detected format and its last line (Settings > Sources). A
+// POST, so that read-only accounts cannot read files through it.
+func (a *API) filesDetect(w http.ResponseWriter, r *http.Request) {
+	var req struct {
+		Path string `json:"path"`
+	}
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&req); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	writeJSON(w, http.StatusOK, DetectFile(req.Path))
+}
+
+// GET /api/selflog: state of the LogStream internal logs (Settings > Sources).
+func (a *API) selfLogStatus(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, a.selfLog.Status())
+}
+
+// PUT /api/selflog {"enabled": bool, "min_level": "warning"}
+func (a *API) selfLogConfigure(w http.ResponseWriter, r *http.Request) {
+	var cfg selfLogConfig
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&cfg); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	if err := a.selfLog.Configure(cfg); err != nil {
+		writeErr(w, http.StatusInternalServerError, err)
+		return
+	}
+	log.Printf("internal logs changed from %s: %+v", r.RemoteAddr, cfg)
+	writeJSON(w, http.StatusOK, a.selfLog.Status())
+}
+
+// GET /api/dmesg: state of the kernel messages source (Settings > Sources).
+func (a *API) dmesgStatus(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, a.dmesg.Status())
+}
+
+// PUT /api/dmesg {"enabled": bool}
+func (a *API) dmesgConfigure(w http.ResponseWriter, r *http.Request) {
+	var cfg dmesgConfig
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4096)).Decode(&cfg); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	if err := a.dmesg.Configure(cfg); err != nil {
+		writeErr(w, http.StatusInternalServerError, err)
+		return
+	}
+	log.Printf("kernel messages source changed from %s: %+v", r.RemoteAddr, cfg)
+	writeJSON(w, http.StatusOK, a.dmesg.Status())
 }
 
 // GET /api/hostlogs: state of the host system logs source (Settings > Sources).
@@ -312,10 +426,25 @@ func (a *API) stats(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, s)
 }
 
+// GET /api/dbstats[?refresh=1]: size and content of the VictoriaLogs base
+// (Settings > Data), cached for 30 s.
+func (a *API) dbStats(w http.ResponseWriter, r *http.Request) {
+	st, err := a.dbstats.get(r.Context(), a.store, r.URL.Query().Get("refresh") == "1")
+	if err != nil {
+		writeErr(w, http.StatusBadGateway, err)
+		return
+	}
+	writeJSON(w, http.StatusOK, st)
+}
+
 func (a *API) listTags(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, a.tags.List())
 }
 
+func (a *API) listPresets(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, loadPresets(a.presets))
+}
+
 func decodeTag(w http.ResponseWriter, r *http.Request) (Tag, error) {
 	var t Tag
 	err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 64*1024)).Decode(&t)
@@ -404,6 +533,41 @@ func (a *API) purge(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]string{"task_id": id})
 }
 
+// PUT /api/tags [tags]: replaces the whole list. On an invalid tag, "index"
+// gives its position and nothing is saved.
+func (a *API) replaceTags(w http.ResponseWriter, r *http.Request) {
+	var in []Tag
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 1<<20)).Decode(&in); err != nil {
+		writeErr(w, http.StatusBadRequest, err)
+		return
+	}
+	tags, err := a.tags.Replace(in)
+	var le *tagListError
+	switch {
+	case errors.As(err, &le):
+		body := map[string]any{"error": err.Error(), "index": le.index}
+		var ce *codedError
+		if errors.As(err, &ce) {
+			body["code"] = ce.code
+			if ce.detail != "" {
+				body["detail"] = ce.detail
+			}
+		}
+		writeJSON(w, http.StatusBadRequest, body)
+	case errors.Is(err, errTooManyTags):
+		writeErr(w, http.StatusBadRequest, err)
+	case err != nil:
+		writeErr(w, http.StatusInternalServerError, err)
+	default:
+		writeJSON(w, http.StatusOK, tags)
+	}
+}
+
+// GET /api/tags/defaults: the tags "Restore default tags" shows before saving.
+func (a *API) defaultTags(w http.ResponseWriter, r *http.Request) {
+	writeJSON(w, http.StatusOK, defaultTags())
+}
+
 func (a *API) resetTags(w http.ResponseWriter, r *http.Request) {
 	tags, err := a.tags.Reset()
 	if err != nil {

audit.go

@@ -0,0 +1,830 @@
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"context"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unicode/utf8"
+)
+
+// auditConfig is saved in /data/audit.json and edited in Settings > Sources.
+type auditConfig struct {
+	Enabled bool   `json:"enabled"`
+	Path    string `json:"path"` // empty: AUDIT_LOG (/var/log/audit/audit.log)
+}
+
+// auditPos is where reading resumes: the inode of the file and an offset
+// before which every event was sent.
+type auditPos struct {
+	Ino uint64 `json:"ino"`
+	Off int64  `json:"off"`
+}
+
+// Audit follows the log of the Linux audit daemon (auditd) and sends one
+// entry per audit event: the records of an event (SYSCALL, EXECVE, PATH…)
+// share the same msg=audit(time:serial) and are grouped together.
+type Audit struct {
+	defPath   string
+	hostRoot  string // to read the host's /etc/passwd and /etc/hostname when mounted
+	hostName  string // AUDIT_HOST: host name of the entries when records have no node=
+	sink      func(*Entry)
+	backfill  time.Duration
+	cfgPath   string
+	statePath string
+	wake      chan struct{}
+
+	// Owned by the Run goroutine.
+	pos       auditPos // checkpoint saved in /data
+	readOff   int64    // where the next read starts (after the lines of open events)
+	known     bool
+	dirty     bool
+	notBefore time.Time
+	asm       *auditAssembler
+	users     *userNames
+
+	mu        sync.Mutex
+	cfg       auditConfig
+	reset     bool
+	open      bool
+	read      uint64
+	errCode   string
+	errDetail string
+}
+
+func NewAudit(defPath, hostRoot, hostName, dataDir string, backfill time.Duration, sink func(*Entry)) *Audit {
+	a := &Audit{
+		defPath:   defPath,
+		hostRoot:  hostRoot,
+		hostName:  hostName,
+		sink:      sink,
+		backfill:  backfill,
+		cfgPath:   filepath.Join(dataDir, "audit.json"),
+		statePath: filepath.Join(dataDir, "audit-state.json"),
+		wake:      make(chan struct{}, 1),
+		asm:       newAuditAssembler(),
+		users:     &userNames{path: filepath.Join(hostRoot, "etc/passwd")},
+	}
+	if b, err := os.ReadFile(a.cfgPath); err == nil {
+		_ = json.Unmarshal(b, &a.cfg)
+	}
+	if b, err := os.ReadFile(a.statePath); err == nil && json.Unmarshal(b, &a.pos) == nil {
+		a.known, a.readOff = true, a.pos.Off
+	}
+	if a.hostName == "" {
+		a.hostName = readTrim(filepath.Join(hostRoot, "etc/hostname"))
+	}
+	return a
+}
+
+func (a *Audit) path() string {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	if a.cfg.Path != "" {
+		return a.cfg.Path
+	}
+	return a.defPath
+}
+
+// Run polls the file every second while the source is enabled.
+func (a *Audit) Run(ctx context.Context) {
+	tick := time.NewTicker(time.Second)
+	defer tick.Stop()
+	n := 0
+	for {
+		select {
+		case <-ctx.Done():
+			a.emit(a.asm.flushAll())
+			a.checkpoint()
+			a.saveState()
+			return
+		case <-tick.C:
+		case <-a.wake:
+		}
+		a.mu.Lock()
+		enabled, reset := a.cfg.Enabled, a.reset
+		a.reset = false
+		a.mu.Unlock()
+		if reset {
+			// Disabled then enabled again (or another file): start over from
+			// AUDIT_BACKFILL ago rather than reading everything in between.
+			a.asm = newAuditAssembler()
+			a.pos, a.readOff, a.known, a.dirty = auditPos{}, 0, false, true
+		}
+		if enabled {
+			a.poll(time.Now())
+		}
+		if n++; n%5 == 0 || reset {
+			a.saveState()
+		}
+	}
+}
+
+func (a *Audit) saveState() {
+	if !a.dirty {
+		return
+	}
+	a.dirty = false
+	if err := writeJSONFile(a.statePath, a.pos); err != nil {
+		logEvent("audit", 4, "saving position: %v", err)
+	}
+}
+
+func (a *Audit) fail(err error) {
+	code := "read"
+	switch {
+	case errors.Is(err, fs.ErrNotExist):
+		code = "not_found"
+	case errors.Is(err, fs.ErrPermission):
+		code = "permission"
+	}
+	a.mu.Lock()
+	changed := code != a.errCode
+	a.open, a.errCode, a.errDetail = false, code, err.Error()
+	a.mu.Unlock()
+	if changed {
+		logEvent("audit", 4, "cannot read the audit log: %v", err)
+	}
+}
+
+const maxAuditRead = 4 << 20 // per poll
+
+// poll reads the lines added since the previous one, follows rotations and
+// sends the events that are complete.
+func (a *Audit) poll(now time.Time) {
+	path := a.path()
+	fi, err := os.Stat(path)
+	if err != nil {
+		a.fail(err)
+		return
+	}
+	ino := inodeOf(fi)
+	if !a.known {
+		// First read: the last AUDIT_BACKFILL (0: only new events).
+		a.pos, a.readOff, a.known, a.dirty = auditPos{Ino: ino}, 0, true, true
+		a.notBefore = time.Time{}
+		if a.backfill <= 0 {
+			a.readOff = fi.Size()
+		} else {
+			a.notBefore = now.Add(-a.backfill)
+		}
+	}
+	if a.pos.Ino != ino {
+		// Rotated by auditd (audit.log -> audit.log.1): finish the old file,
+		// then read the new one from its start.
+		if old, err := os.Stat(path + ".1"); err == nil && inodeOf(old) == a.pos.Ino {
+			for {
+				off, more, err := a.readFrom(path+".1", a.readOff, now)
+				if err != nil || !more {
+					break
+				}
+				a.readOff = off
+			}
+		}
+		a.emit(a.asm.flushAll())
+		a.pos, a.readOff, a.dirty = auditPos{Ino: ino}, 0, true
+	} else if fi.Size() < a.readOff {
+		a.emit(a.asm.flushAll()) // truncated
+		a.readOff = 0
+	}
+	if fi.Size() > a.readOff {
+		off, _, err := a.readFrom(path, a.readOff, now)
+		if err != nil {
+			a.fail(err)
+			return
+		}
+		a.readOff = off
+	}
+	a.mu.Lock()
+	if !a.open {
+		a.open, a.errCode, a.errDetail = true, "", ""
+	}
+	a.mu.Unlock()
+	a.emit(a.asm.flush(now, auditCloseDelay))
+	a.checkpoint()
+}
+
+// checkpoint saves an offset before which every event is sent: the start of
+// the oldest event still open, or the read offset.
+func (a *Audit) checkpoint() {
+	off := a.readOff
+	if o, ok := a.asm.minOff(); ok && o < off {
+		off = o
+	}
+	if off != a.pos.Off {
+		a.pos.Off, a.dirty = off, true
+	}
+}
+
+// readFrom feeds the complete lines written after off to the assembler and
+// returns the new offset; more tells whether the read window was full.
+func (a *Audit) readFrom(path string, off int64, now time.Time) (int64, bool, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return off, false, err
+	}
+	defer f.Close()
+	buf, err := io.ReadAll(io.NewSectionReader(f, off, maxAuditRead))
+	if err != nil {
+		return off, false, err
+	}
+	full := len(buf) == maxAuditRead
+	end := bytes.LastIndexByte(buf, '\n')
+	if end < 0 {
+		if !full {
+			return off, false, nil // partial line: wait for its end
+		}
+		end = len(buf) - 1
+	}
+	start := off
+	for _, line := range bytes.Split(buf[:end], []byte{'\n'}) {
+		a.emit(a.asm.add(string(line), start, now))
+		start += int64(len(line)) + 1
+	}
+	return off + int64(end) + 1, full, nil
+}
+
+func (a *Audit) emit(evs []*auditEvent) {
+	for _, ev := range evs {
+		if !a.notBefore.IsZero() && ev.Time.Before(a.notBefore) {
+			continue
+		}
+		a.sink(auditEntry(ev, a.users, a.hostName, time.Now()))
+		a.mu.Lock()
+		a.read++
+		a.mu.Unlock()
+	}
+}
+
+func inodeOf(fi os.FileInfo) uint64 {
+	if st, ok := fi.Sys().(*syscall.Stat_t); ok {
+		return uint64(st.Ino)
+	}
+	return 0
+}
+
+// Configure saves and applies the configuration.
+func (a *Audit) Configure(cfg auditConfig) error {
+	cfg.Path = strings.TrimSpace(cfg.Path)
+	a.mu.Lock()
+	if (a.cfg.Enabled && !cfg.Enabled) || cfg.Path != a.cfg.Path {
+		a.reset = true
+		a.open, a.errCode, a.errDetail = false, "", ""
+	}
+	a.cfg = cfg
+	a.mu.Unlock()
+	select {
+	case a.wake <- struct{}{}:
+	default:
+	}
+	return writeJSONFile(a.cfgPath, cfg)
+}
+
+// Status is the state shown in Settings > Sources.
+func (a *Audit) Status() map[string]any {
+	a.mu.Lock()
+	defer a.mu.Unlock()
+	return map[string]any{
+		"enabled":     a.cfg.Enabled,
+		"path":        a.cfg.Path,
+		"defaultPath": a.defPath,
+		"open":        a.open && a.cfg.Enabled,
+		"read":        a.read,
+		"code":        a.errCode,
+		"error":       a.errDetail,
+	}
+}
+
+/* ---------- Records and events ---------- */
+
+// auditCloseDelay: an event is complete when no line of it came for this
+// long, or when the log has moved this far past its time (auditd does not
+// write the EOE record that ends multi-record events).
+const auditCloseDelay = 2 * time.Second
+
+type auditField struct {
+	k, v string
+	bare bool // written without quotes: may be hexadecimal
+}
+
+type auditRecord struct {
+	Type   string
+	Fields []auditField
+	Raw    string
+}
+
+type auditEvent struct {
+	ID      string // "1700000000.123:456"
+	Serial  string
+	Time    time.Time
+	Node    string
+	Records []auditRecord
+	off     int64     // offset of its first line in the file
+	seen    time.Time // when its last line was read
+	order   int
+}
+
+// parseAuditLine decodes "[node=N ]type=T msg=audit(SEC.MS:SERIAL): k=v …".
+func parseAuditLine(line string) (rec auditRecord, id, node string, ok bool) {
+	line = strings.TrimRight(line, "\r")
+	rec.Raw = line
+	head, rest, found := strings.Cut(line, "): ")
+	if !found {
+		head, found = strings.CutSuffix(line, ")")
+		if !found {
+			return rec, "", "", false
+		}
+	}
+	pre, ts, found := strings.Cut(head, "msg=audit(")
+	if !found || ts == "" {
+		return rec, "", "", false
+	}
+	for _, f := range parseAuditKV(pre) {
+		switch f.k {
+		case "type":
+			rec.Type = f.v
+		case "node":
+			node = f.v
+		}
+	}
+	if rec.Type == "" {
+		return rec, "", "", false
+	}
+	// Enriched format (log_format=ENRICHED): resolved values after a GS byte.
+	main, enriched, _ := strings.Cut(rest, "\x1d")
+	rec.Fields = parseAuditKV(main)
+	for _, f := range parseAuditKV(enriched) {
+		rec.Fields = append(rec.Fields, auditField{k: "@" + f.k, v: f.v})
+	}
+	return rec, ts, node, true
+}
+
+// hexFields are the fields auditd writes in hexadecimal when they contain
+// spaces, quotes or control characters (and then without quotes).
+var hexFields = map[string]bool{
+	"proctitle": true, "cmd": true, "exe": true, "comm": true, "key": true, "acct": true,
+	"name": true, "cwd": true, "data": true, "path": true, "old": true, "new": true,
+}
+
+// parseAuditKV splits "k=v k2="v 2" msg='k3=v3 …'"; the fields of a quoted
+// msg='…' (user space records) follow the outer ones.
+func parseAuditKV(s string) []auditField {
+	var out []auditField
+	var inner []auditField
+	for i := 0; i < len(s); {
+		for i < len(s) && s[i] == ' ' {
+			i++
+		}
+		eq := strings.IndexByte(s[i:], '=')
+		if eq <= 0 {
+			break
+		}
+		k := s[i : i+eq]
+		if sp := strings.IndexByte(k, ' '); sp >= 0 { // word without value
+			i += sp + 1
+			continue
+		}
+		i += eq + 1
+		var v string
+		quoted := i < len(s) && (s[i] == '"' || s[i] == '\'')
+		if quoted {
+			q := s[i]
+			end := strings.IndexByte(s[i+1:], q)
+			if end < 0 {
+				end = len(s) - i - 1
+			}
+			v = s[i+1 : i+1+end]
+			i += end + 2
+		} else {
+			end := strings.IndexByte(s[i:], ' ')
+			if end < 0 {
+				end = len(s) - i
+			}
+			v = s[i : i+end]
+			i += end
+		}
+		if k == "msg" && quoted && strings.Contains(v, "=") {
+			inner = append(inner, parseAuditKV(v)...)
+			continue
+		}
+		if !quoted && hexFields[k] {
+			v = decodeHex(k, v)
+		}
+		if !quoted && (v == "(null)" || v == "?") {
+			v = ""
+		}
+		out = append(out, auditField{k: k, v: v, bare: !quoted})
+	}
+	return append(out, inner...)
+}
+
+// decodeHex decodes a hexadecimal value, or returns it unchanged.
+func decodeHex(k, v string) string {
+	if len(v) < 2 || len(v)%2 != 0 {
+		return v
+	}
+	b, err := hex.DecodeString(v)
+	if err != nil {
+		return v
+	}
+	if k == "proctitle" {
+		b = bytes.ReplaceAll(bytes.TrimRight(b, "\x00"), []byte{0}, []byte{' '})
+	}
+	if !utf8.Valid(b) {
+		return v
+	}
+	return string(b)
+}
+
+func isDigits(s string) bool {
+	for i := 0; i < len(s); i++ {
+		if s[i] < '0' || s[i] > '9' {
+			return false
+		}
+	}
+	return s != ""
+}
+
+// parseAuditTime decodes "1700000000.123:456" into a time and a serial.
+func parseAuditTime(id string) (time.Time, string) {
+	ts, serial, _ := strings.Cut(id, ":")
+	sec, frac, _ := strings.Cut(ts, ".")
+	s, err := strconv.ParseInt(sec, 10, 64)
+	if err != nil {
+		return time.Time{}, serial
+	}
+	ms, _ := strconv.ParseInt((frac + "000")[:3], 10, 64)
+	return time.Unix(s, ms*int64(time.Millisecond)), serial
+}
+
+// auditAssembler groups the records of each event.
+type auditAssembler struct {
+	open   map[string]*auditEvent
+	newest time.Time // most recent event time read
+	n      int
+}
+
+func newAuditAssembler() *auditAssembler {
+	return &auditAssembler{open: map[string]*auditEvent{}}
+}
+
+const maxOpenAudit = 2000
+
+// add takes one line read at offset off and returns the events it completes
+// (EOE record, or too many events open).
+func (a *auditAssembler) add(line string, off int64, now time.Time) []*auditEvent {
+	if strings.TrimSpace(line) == "" {
+		return nil
+	}
+	rec, id, node, ok := parseAuditLine(line)
+	if !ok {
+		return nil
+	}
+	ev := a.open[id]
+	if rec.Type == "EOE" {
+		if ev == nil {
+			return nil
+		}
+		delete(a.open, id)
+		return []*auditEvent{ev}
+	}
+	if ev == nil {
+		t, serial := parseAuditTime(id)
+		a.n++
+		ev = &auditEvent{ID: id, Serial: serial, Time: t, Node: node, off: off, order: a.n}
+		a.open[id] = ev
+		if t.After(a.newest) {
+			a.newest = t
+		}
+	}
+	ev.Records = append(ev.Records, rec)
+	ev.seen = now
+	if len(a.open) > maxOpenAudit {
+		return a.closeOldest(len(a.open) - maxOpenAudit/2)
+	}
+	return nil
+}
+
+// flush returns the events with no new line for delay, or that the log has
+// left delay behind, in the order they started.
+func (a *auditAssembler) flush(now time.Time, delay time.Duration) []*auditEvent {
+	var out []*auditEvent
+	for id, ev := range a.open {
+		if now.Sub(ev.seen) >= delay || a.newest.Sub(ev.Time) >= delay {
+			out = append(out, ev)
+			delete(a.open, id)
+		}
+	}
+	sortEvents(out)
+	return out
+}
+
+func (a *auditAssembler) flushAll() []*auditEvent {
+	return a.closeOldest(len(a.open))
+}
+
+func (a *auditAssembler) closeOldest(n int) []*auditEvent {
+	all := make([]*auditEvent, 0, len(a.open))
+	for _, ev := range a.open {
+		all = append(all, ev)
+	}
+	sortEvents(all)
+	all = all[:n]
+	for _, ev := range all {
+		delete(a.open, ev.ID)
+	}
+	return all
+}
+
+func sortEvents(evs []*auditEvent) {
+	sort.Slice(evs, func(i, j int) bool { return evs[i].order < evs[j].order })
+}
+
+func (a *auditAssembler) minOff() (int64, bool) {
+	var m int64
+	ok := false
+	for _, ev := range a.open {
+		if !ok || ev.off < m {
+			m, ok = ev.off, true
+		}
+	}
+	return m, ok
+}
+
+/* ---------- Entries ---------- */
+
+// get returns the first non-empty value of a field across the records.
+func (ev *auditEvent) get(k string) string {
+	for _, r := range ev.Records {
+		for _, f := range r.Fields {
+			if f.k == k && f.v != "" {
+				return f.v
+			}
+		}
+	}
+	return ""
+}
+
+func (ev *auditEvent) record(typ string) *auditRecord {
+	for i := range ev.Records {
+		if ev.Records[i].Type == typ {
+			return &ev.Records[i]
+		}
+	}
+	return nil
+}
+
+// result is "success", "failed" or "" from res= or success=.
+func (ev *auditEvent) result() string {
+	v := strings.ToLower(firstNonEmpty(ev.get("res"), ev.get("success"), ev.get("result")))
+	switch v {
+	case "success", "yes", "1":
+		return "success"
+	case "failed", "fail", "failure", "no", "0":
+		return "failed"
+	}
+	return ""
+}
+
+const auditUnset = "4294967295"
+
+// userOf resolves a uid: enriched name, then the host's /etc/passwd, then the number.
+func (ev *auditEvent) userOf(field string, users *userNames) string {
+	uid := ev.get(field)
+	if uid == "" || uid == auditUnset || uid == "-1" {
+		return ""
+	}
+	if n := strings.Trim(ev.get("@"+strings.ToUpper(field)), `"`); n != "" && n != "unset" && n != uid {
+		return n
+	}
+	if n := users.name(uid); n != "" {
+		return n
+	}
+	return uid
+}
+
+// auditEntry turns an event into an Entry: app is the type of its first record.
+func auditEntry(ev *auditEvent, users *userNames, hostName string, now time.Time) *Entry {
+	typ := "UNKNOWN"
+	if len(ev.Records) > 0 {
+		typ = ev.Records[0].Type
+	}
+	res := ev.result()
+	auid := ev.get("auid")
+	user := ev.userOf("auid", users)
+	if user == "" {
+		user = ev.userOf("uid", users)
+	}
+	sev := 6
+	if res == "failed" {
+		sev = 4
+	}
+	raw := make([]string, len(ev.Records))
+	for i, r := range ev.Records {
+		raw[i] = r.Raw
+	}
+	host := firstNonEmpty(ev.Node, hostName, "localhost")
+	e := &Entry{
+		Time:       ev.Time,
+		Received:   now,
+		Host:       host,
+		App:        typ,
+		ProcID:     ev.get("pid"),
+		Facility:   "authpriv",
+		Severity:   severityNames[sev],
+		SevNum:     sev,
+		Message:    auditSummary(ev, typ, user, users, res),
+		Proto:      "file",
+		SourceType: "audit",
+		Extra: map[string]string{
+			"audit_type":   typ,
+			"audit_serial": ev.Serial,
+			"auid":         auid,
+			"user":         user,
+			"exe":          ev.get("exe"),
+			"res":          res,
+			"key":          ev.get("key"),
+			"audit_raw":    strings.Join(raw, "\n"),
+		},
+		Wait: true,
+	}
+	if e.Time.IsZero() {
+		e.Time = now
+	}
+	return e
+}
+
+// auditSummary writes "who: what [key] → result".
+func auditSummary(ev *auditEvent, typ, user string, users *userNames, res string) string {
+	who := firstNonEmpty(user, "?")
+	// Syscalls: the login user and, when different, the user the process ran
+	// as (sudo, su). In user space records, uid is the daemon's (sshd: root).
+	if uid := ev.userOf("uid", users); ev.get("syscall") != "" && uid != "" && user != "" && uid != user {
+		who += " (as " + uid + ")"
+	}
+	var what string
+	exe := ev.get("exe")
+	switch {
+	case typ == "USER_CMD":
+		what = "sudo " + firstNonEmpty(ev.get("cmd"), "?")
+		if cwd := ev.get("cwd"); cwd != "" {
+			what += " (in " + cwd + ")"
+		}
+	case strings.HasPrefix(typ, "USER_") || strings.HasPrefix(typ, "CRED_") || typ == "LOGIN" ||
+		typ == "ADD_USER" || typ == "DEL_USER" || typ == "ADD_GROUP" || typ == "DEL_GROUP":
+		if acct := ev.get("acct"); acct != "" {
+			who = acct
+		}
+		what = firstNonEmpty(ev.get("op"), strings.ToLower(typ))
+		if exe != "" {
+			what += " via " + exe
+		}
+		if addr := firstNonEmpty(ev.get("hostname"), ev.get("addr")); addr != "" {
+			what += " from " + addr
+		}
+		if term := ev.get("terminal"); term != "" && term != "?" {
+			what += " on " + term
+		}
+	case ev.record("EXECVE") != nil:
+		what = "exec " + execLine(ev.record("EXECVE"))
+	case ev.get("syscall") != "":
+		what = "syscall " + firstNonEmpty(ev.get("@SYSCALL"), ev.get("syscall"))
+		if name := pathName(ev); name != "" {
+			what += " " + name
+		}
+		if prog := firstNonEmpty(exe, ev.get("comm")); prog != "" {
+			what += " by " + prog
+		}
+	default:
+		what = strings.ToLower(typ)
+		if op := ev.get("op"); op != "" {
+			what += " " + op
+		}
+		if exe != "" {
+			what += " by " + exe
+		}
+	}
+	if key := ev.get("key"); key != "" {
+		what += " [" + key + "]"
+	}
+	if res != "" {
+		what += " → " + res
+	}
+	return who + ": " + what
+}
+
+// execLine joins the arguments of an EXECVE record (a0, a1…).
+func execLine(r *auditRecord) string {
+	args := map[int]string{}
+	argc := 0
+	for _, f := range r.Fields {
+		if f.k == "argc" {
+			argc, _ = strconv.Atoi(f.v)
+		} else if len(f.k) > 1 && f.k[0] == 'a' && isDigits(f.k[1:]) {
+			n, _ := strconv.Atoi(f.k[1:])
+			if f.bare {
+				args[n] = decodeHex(f.k, f.v) // arguments with spaces or quotes
+			} else {
+				args[n] = f.v
+			}
+		}
+	}
+	if argc == 0 {
+		argc = len(args)
+	}
+	parts := make([]string, 0, argc)
+	for i := 0; i < argc; i++ {
+		if v, ok := args[i]; ok {
+			parts = append(parts, v)
+		}
+	}
+	s := strings.Join(parts, " ")
+	if len(s) > 300 {
+		s = s[:300] + "…"
+	}
+	return s
+}
+
+// pathName is the file a syscall worked on: the first PATH record that is not
+// its parent directory.
+func pathName(ev *auditEvent) string {
+	var first string
+	for _, r := range ev.Records {
+		if r.Type != "PATH" {
+			continue
+		}
+		var name, nametype string
+		for _, f := range r.Fields {
+			switch f.k {
+			case "name":
+				name = f.v
+			case "nametype":
+				nametype = f.v
+			}
+		}
+		if name == "" {
+			continue
+		}
+		if nametype != "PARENT" {
+			return name
+		}
+		if first == "" {
+			first = name
+		}
+	}
+	return first
+}
+
+/* ---------- User names ---------- */
+
+// userNames reads uid -> name from the host's /etc/passwd when it is mounted,
+// at most once a minute.
+type userNames struct {
+	path    string
+	names   map[string]string
+	loaded  time.Time
+	modTime time.Time
+}
+
+func (u *userNames) name(uid string) string {
+	if u == nil {
+		return ""
+	}
+	if time.Since(u.loaded) > time.Minute {
+		u.loaded = time.Now()
+		if fi, err := os.Stat(u.path); err == nil && !fi.ModTime().Equal(u.modTime) {
+			u.modTime = fi.ModTime()
+			u.names = readPasswd(u.path)
+		}
+	}
+	return u.names[uid]
+}
+
+func readPasswd(path string) map[string]string {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil
+	}
+	defer f.Close()
+	names := map[string]string{}
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		p := strings.Split(sc.Text(), ":")
+		if len(p) >= 3 && p[0] != "" && !strings.HasPrefix(p[0], "#") {
+			names[p[2]] = p[0]
+		}
+	}
+	return names
+}

audit_test.go

@@ -0,0 +1,356 @@
+package main
+
+import (
+	"context"
+	"encoding/hex"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+func hexOf(s string) string { return strings.ToUpper(hex.EncodeToString([]byte(s))) }
+
+// Lines of real audit.log events (trimmed).
+var (
+	auditExec = []string{
+		`type=SYSCALL msg=audit(1759572000.123:4242): arch=c000003e syscall=59 success=yes exit=0 a0=4142 a1=55d2 a2=55d3 a3=0 items=2 ppid=1000 pid=1234 auid=1000 uid=0 gid=0 euid=0 tty=pts0 ses=3 comm="apt" exe="/usr/bin/apt" subj=unconfined key="exec"`,
+		`type=EXECVE msg=audit(1759572000.123:4242): argc=3 a0="apt" a1="install" a2=` + hexOf(`my "pkg"`),
+		`type=CWD msg=audit(1759572000.123:4242): cwd="/root"`,
+		`type=PATH msg=audit(1759572000.123:4242): item=0 name="/usr/bin/apt" inode=1 dev=fd:00 mode=0100755 ouid=0 ogid=0 nametype=NORMAL`,
+		`type=PROCTITLE msg=audit(1759572000.123:4242): proctitle=` + hexOf("apt\x00install\x00my \"pkg\""),
+	}
+	auditSudo = `type=USER_CMD msg=audit(1759572001.500:4250): pid=2000 uid=1000 auid=1000 ses=3 subj=unconfined msg='cwd="/home/cedric" cmd=` + hexOf("systemctl restart nginx") + ` exe="/usr/bin/sudo" terminal=pts/0 res=success'`
+	auditSSH  = `type=USER_AUTH msg=audit(1759572002.000:4260): pid=3000 uid=0 auid=4294967295 ses=4294967295 subj=unconfined msg='op=PAM:authentication grantors=? acct="bob" exe="/usr/sbin/sshd" hostname=203.0.113.9 addr=203.0.113.9 terminal=ssh res=failed'`
+	auditOpen = []string{
+		"node=web1 type=SYSCALL msg=audit(1759572003.250:4270): arch=c000003e syscall=257 success=no exit=-13 items=1 pid=4000 auid=1001 uid=1001 comm=\"cat\" exe=\"/usr/bin/cat\" key=\"shadow\"\x1dARCH=x86_64 SYSCALL=openat AUID=\"alice\" UID=\"alice\"",
+		`node=web1 type=PATH msg=audit(1759572003.250:4270): item=0 name="/etc/shadow" inode=7 nametype=NORMAL`,
+	}
+)
+
+func TestParseAuditLine(t *testing.T) {
+	rec, id, node, ok := parseAuditLine(auditOpen[0])
+	if !ok || rec.Type != "SYSCALL" || id != "1759572003.250:4270" || node != "web1" {
+		t.Fatalf("got %+v %q %q %v", rec, id, node, ok)
+	}
+	ev := &auditEvent{Records: []auditRecord{rec}}
+	for k, want := range map[string]string{"syscall": "257", "exe": "/usr/bin/cat", "key": "shadow", "@SYSCALL": "openat", "@AUID": "alice"} {
+		if got := ev.get(k); got != want {
+			t.Errorf("%s = %q, want %q", k, got, want)
+		}
+	}
+	for _, bad := range []string{"", "garbage", "type=X no header", "msg=audit(1.2:3): no type"} {
+		if _, _, _, ok := parseAuditLine(bad); ok {
+			t.Errorf("%q parsed", bad)
+		}
+	}
+}
+
+func TestParseAuditKV(t *testing.T) {
+	tests := []struct {
+		in   string
+		want map[string]string
+	}{
+		{`a=1 b="two words" c=`, map[string]string{"a": "1", "b": "two words", "c": ""}},
+		{`pid=1 msg='op=login acct="bob" res=success'`, map[string]string{"pid": "1", "op": "login", "acct": "bob", "res": "success"}},
+		{`comm=` + hexOf("my prog") + ` exe="/bin/x"`, map[string]string{"comm": "my prog", "exe": "/bin/x"}},
+		{`key=(null) hostname=? terminal=?`, map[string]string{"key": "", "hostname": "", "terminal": ""}},
+		{`a0=4142 name=ABC`, map[string]string{"a0": "4142", "name": "ABC"}}, // not hexadecimal fields, or odd length
+		{`avc:  denied  { read } for  pid=12 comm="x"`, map[string]string{"pid": "12", "comm": "x"}},
+	}
+	for _, tt := range tests {
+		got := map[string]string{}
+		for _, f := range parseAuditKV(tt.in) {
+			got[f.k] = f.v
+		}
+		for k, v := range tt.want {
+			if got[k] != v {
+				t.Errorf("%q: %s = %q, want %q (all: %v)", tt.in, k, got[k], v, got)
+			}
+		}
+	}
+}
+
+func TestAuditAssembler(t *testing.T) {
+	now := time.Unix(1759572010, 0)
+	a := newAuditAssembler()
+	// Two interleaved events, then an EOE that closes the first one.
+	lines := []string{auditExec[0], auditSudo, auditExec[1], auditExec[2]}
+	off := int64(0)
+	for _, l := range lines {
+		if out := a.add(l, off, now); out != nil {
+			t.Fatalf("closed early: %v", out)
+		}
+		off += int64(len(l)) + 1
+	}
+	if len(a.open) != 2 {
+		t.Fatalf("%d open events", len(a.open))
+	}
+	if o, ok := a.minOff(); !ok || o != 0 {
+		t.Fatalf("minOff %d %v", o, ok)
+	}
+	out := a.add(`type=EOE msg=audit(1759572000.123:4242): `, off, now)
+	if len(out) != 1 || out[0].Serial != "4242" || len(out[0].Records) != 3 {
+		t.Fatalf("EOE: %+v", out)
+	}
+	if o, _ := a.minOff(); o != int64(len(lines[0])+1) {
+		t.Fatalf("minOff after EOE: %d", o)
+	}
+	// An EOE of an unknown event is ignored.
+	if out := a.add(`type=EOE msg=audit(1.0:1): `, 0, now); out != nil {
+		t.Fatal(out)
+	}
+	// The sudo event is closed by time.
+	if out := a.flush(now.Add(time.Second), 2*time.Second); len(out) != 0 {
+		t.Fatalf("closed too early: %v", out)
+	}
+	out = a.flush(now.Add(3*time.Second), 2*time.Second)
+	if len(out) != 1 || out[0].Records[0].Type != "USER_CMD" {
+		t.Fatalf("flush: %+v", out)
+	}
+	// Events the log has left behind are closed without waiting.
+	a.add(auditSSH, 0, now)
+	a.add(auditOpen[0], 0, now)
+	out = a.flush(now, 1*time.Second)
+	if len(out) != 1 || out[0].Serial != "4260" || len(a.open) != 1 {
+		t.Fatalf("newest: %+v, open %d", out, len(a.open))
+	}
+	if out = a.flushAll(); len(out) != 1 || out[0].Serial != "4270" || len(a.open) != 0 {
+		t.Fatalf("flushAll: %+v", out)
+	}
+}
+
+func auditEv(t *testing.T, lines ...string) *auditEvent {
+	t.Helper()
+	a := newAuditAssembler()
+	for _, l := range lines {
+		a.add(l, 0, time.Time{})
+	}
+	out := a.flushAll()
+	if len(out) != 1 {
+		t.Fatalf("%d events", len(out))
+	}
+	return out[0]
+}
+
+func TestAuditEntry(t *testing.T) {
+	dir := t.TempDir()
+	passwd := filepath.Join(dir, "passwd")
+	if err := os.WriteFile(passwd, []byte("root:x:0:0::/root:/bin/sh\ncedric:x:1000:1000::/home/cedric:/bin/bash\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	now := time.Unix(1759572100, 0)
+	tests := []struct {
+		name   string
+		lines  []string
+		host   string
+		app    string
+		sev    string
+		msg    string
+		fields map[string]string
+	}{
+		{"exec", auditExec, "srv", "SYSCALL", "info",
+			`cedric (as root): exec apt install my "pkg" [exec] → success`,
+			map[string]string{"audit_type": "SYSCALL", "audit_serial": "4242", "auid": "1000", "user": "cedric", "exe": "/usr/bin/apt", "res": "success", "key": "exec"}},
+		{"sudo", []string{auditSudo}, "srv", "USER_CMD", "info",
+			"cedric: sudo systemctl restart nginx (in /home/cedric) → success",
+			map[string]string{"user": "cedric", "exe": "/usr/bin/sudo", "res": "success", "key": ""}},
+		{"ssh failed", []string{auditSSH}, "srv", "USER_AUTH", "warning",
+			"bob: PAM:authentication via /usr/sbin/sshd from 203.0.113.9 on ssh → failed",
+			map[string]string{"auid": "4294967295", "user": "root", "res": "failed"}},
+		{"enriched, node", auditOpen, "web1", "SYSCALL", "warning",
+			"alice: syscall openat /etc/shadow by /usr/bin/cat [shadow] → failed",
+			map[string]string{"user": "alice", "auid": "1001", "res": "failed", "key": "shadow"}},
+		{"unknown uid", []string{`type=USER_LOGIN msg=audit(1759572004.000:4280): pid=1 uid=0 auid=4242 ses=9 msg='op=login id=4242 exe="/usr/sbin/sshd" hostname=? addr=10.0.0.5 terminal=/dev/pts/1 res=success'`},
+			"srv", "USER_LOGIN", "info", "4242: login via /usr/sbin/sshd from 10.0.0.5 on /dev/pts/1 → success",
+			map[string]string{"user": "4242"}},
+		{"no result", []string{`type=CONFIG_CHANGE msg=audit(1759572005.000:4290): auid=1000 ses=3 op=add_rule key="watch" list=4`},
+			"srv", "CONFIG_CHANGE", "info", "cedric: config_change add_rule [watch]",
+			map[string]string{"res": ""}},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ev := auditEv(t, tt.lines...)
+			e := auditEntry(ev, &userNames{path: passwd}, "srv", now)
+			if e.Host != tt.host || e.App != tt.app || e.Severity != tt.sev || e.SourceType != "audit" || !e.Wait {
+				t.Errorf("entry %+v", e)
+			}
+			if e.Message != tt.msg {
+				t.Errorf("message\n got %q\nwant %q", e.Message, tt.msg)
+			}
+			for k, v := range tt.fields {
+				if e.Extra[k] != v {
+					t.Errorf("%s = %q, want %q", k, e.Extra[k], v)
+				}
+			}
+			if e.Extra["audit_raw"] != strings.Join(tt.lines, "\n") {
+				t.Errorf("raw %q", e.Extra["audit_raw"])
+			}
+			if !e.Time.Equal(ev.Time) || e.Time.IsZero() {
+				t.Errorf("time %v", e.Time)
+			}
+		})
+	}
+}
+
+type entrySink struct {
+	mu sync.Mutex
+	es []*Entry
+}
+
+func (s *entrySink) add(e *Entry) {
+	s.mu.Lock()
+	s.es = append(s.es, e)
+	s.mu.Unlock()
+}
+
+func (s *entrySink) serials() []string {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	var out []string
+	for _, e := range s.es {
+		out = append(out, e.Extra["audit_serial"])
+	}
+	return out
+}
+
+func appendLines(t *testing.T, path string, lines ...string) {
+	t.Helper()
+	f, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer f.Close()
+	for _, l := range lines {
+		if _, err := f.WriteString(l + "\n"); err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
+func TestAuditFollow(t *testing.T) {
+	dir := t.TempDir()
+	logPath := filepath.Join(dir, "audit.log")
+	data := filepath.Join(dir, "data")
+	if err := os.Mkdir(data, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	sink := &entrySink{}
+	newAuditT := func() *Audit {
+		a := NewAudit(logPath, dir, "srv", data, 100*365*24*time.Hour, sink.add)
+		a.cfg.Enabled = true
+		return a
+	}
+	a := newAuditT()
+	now := time.Unix(1759572100, 0)
+
+	// Missing file: reported, then read once it exists.
+	a.poll(now)
+	if st := a.Status(); st["code"] != "not_found" || st["open"] != false {
+		t.Fatalf("status %v", st)
+	}
+	appendLines(t, logPath, auditExec[:3]...)
+	appendLines(t, logPath, auditSudo)
+	a.poll(now)
+	if got := sink.serials(); len(got) != 0 { // events may still get records
+		t.Fatalf("after first poll: %v", got)
+	}
+	// A partial line is not read.
+	f, _ := os.OpenFile(logPath, os.O_APPEND|os.O_WRONLY, 0)
+	f.WriteString(auditSSH[:20])
+	f.Close()
+	a.poll(now.Add(5 * time.Second))
+	if got := sink.serials(); len(got) != 2 || got[0] != "4242" || got[1] != "4250" {
+		t.Fatalf("after second poll: %v", got)
+	}
+	if a.Status()["open"] != true || a.Status()["read"] != uint64(2) {
+		t.Fatalf("status %v", a.Status())
+	}
+	a.saveState()
+
+	// Restart: nothing is sent twice, the partial line is read once complete.
+	a = newAuditT()
+	f, _ = os.OpenFile(logPath, os.O_APPEND|os.O_WRONLY, 0)
+	f.WriteString(auditSSH[20:] + "\n")
+	f.Close()
+	a.poll(now.Add(10 * time.Second))
+	a.poll(now.Add(20 * time.Second))
+	if got := sink.serials(); len(got) != 3 || got[2] != "4260" {
+		t.Fatalf("after restart: %v", got)
+	}
+
+	// Rotation: lines added to the old file before the switch are not lost.
+	appendLines(t, logPath, auditOpen[0])
+	a.poll(now.Add(21 * time.Second)) // read, still open
+	appendLines(t, logPath, auditOpen[1])
+	if err := os.Rename(logPath, logPath+".1"); err != nil {
+		t.Fatal(err)
+	}
+	appendLines(t, logPath, strings.Replace(auditSudo, "4250", "4300", 1))
+	a.poll(now.Add(22 * time.Second))
+	a.poll(now.Add(30 * time.Second))
+	got := sink.serials()
+	if len(got) != 5 || got[3] != "4270" || got[4] != "4300" {
+		t.Fatalf("after rotation: %v", got)
+	}
+	sink.mu.Lock()
+	if n := len(sink.es[3].Extra["audit_raw"]); n == 0 || !strings.Contains(sink.es[3].Extra["audit_raw"], "/etc/shadow") {
+		t.Errorf("rotated event missing its PATH record: %q", sink.es[3].Extra["audit_raw"])
+	}
+	sink.mu.Unlock()
+}
+
+func TestAuditBackfillAndConfigure(t *testing.T) {
+	dir := t.TempDir()
+	logPath := filepath.Join(dir, "audit.log")
+	appendLines(t, logPath, auditExec...)
+	appendLines(t, logPath, auditSudo)
+	sink := &entrySink{}
+	// Only events newer than the backfill window are sent on the first read.
+	a := NewAudit(logPath, dir, "", dir, time.Hour, sink.add)
+	a.cfg.Enabled = true
+	a.poll(time.Unix(1759572001+7200, 0))
+	a.emit(a.asm.flushAll())
+	if got := sink.serials(); len(got) != 0 {
+		t.Fatalf("too old: %v", got)
+	}
+	a = NewAudit(logPath, dir, "", filepath.Join(dir, "other"), time.Hour, sink.add)
+	if err := os.Mkdir(filepath.Join(dir, "other"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	a.cfg.Enabled = true
+	a.poll(time.Unix(1759572001+60, 0))
+	a.emit(a.asm.flushAll())
+	if got := sink.serials(); len(got) != 2 {
+		t.Fatalf("backfill: %v", got)
+	}
+	if e := sink.es[0]; e.Host != "localhost" {
+		t.Errorf("host %q", e.Host)
+	}
+
+	// Run picks the configuration up; turning it off resets the position.
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() { a.Run(ctx); close(done) }()
+	if err := a.Configure(auditConfig{Enabled: false}); err != nil {
+		t.Fatal(err)
+	}
+	deadline := time.Now().Add(2 * time.Second)
+	for time.Now().Before(deadline) {
+		if b, err := os.ReadFile(filepath.Join(dir, "other", "audit-state.json")); err == nil && strings.Contains(string(b), `"off": 0`) {
+			break
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	cancel()
+	<-done
+	if st := a.Status(); st["enabled"] != false || st["defaultPath"] != logPath {
+		t.Fatalf("status %v", st)
+	}
+	b, _ := os.ReadFile(filepath.Join(dir, "other", "audit-state.json"))
+	if !strings.Contains(string(b), `"off": 0`) {
+		t.Fatalf("state %s", b)
+	}
+}

auth.go

@@ -42,6 +42,10 @@ const (
 type authConfig struct {
 	mode         string
 	user, pass   string // local mode
+	viewerUser   string // local mode: optional read-only account
+	viewerPass   string
+	adminGroup   string // oidc: only members of this group are admins (empty: everyone)
+	groupsClaim  string // oidc: ID token claim listing the groups
 	issuer       string
 	clientID     string
 	clientSecret string
@@ -124,6 +128,9 @@ func newOIDC(c authConfig) (*OIDC, error) {
 	if !strings.Contains(" "+c.scopes+" ", " openid ") {
 		c.scopes = "openid " + c.scopes
 	}
+	if c.groupsClaim == "" {
+		c.groupsClaim = "groups"
+	}
 	return &OIDC{
 		cfg:      c,
 		callback: ru.Path,
@@ -157,8 +164,9 @@ func sessionKey(dir string) []byte {
 }
 
 type session struct {
-	User string `json:"u"`
-	Exp  int64  `json:"e"`
+	User   string `json:"u"`
+	Exp    int64  `json:"e"`
+	Viewer bool   `json:"v,omitempty"` // read-only user
 }
 
 // writeAuthRequired answers API calls without a session; the UI turns it into a reload
@@ -191,9 +199,12 @@ func (o *OIDC) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	var s session
 	if c, err := r.Cookie(sessionCookie); err == nil && verifyCookie(o.key, c.Value, &s) && time.Now().Unix() < s.Exp {
 		if r.URL.Path == "/auth/me" {
-			writeJSON(w, http.StatusOK, map[string]string{"mode": "oidc", "user": s.User})
+			writeJSON(w, http.StatusOK, map[string]string{"mode": "oidc", "user": s.User, "role": roleName(s.Viewer)})
 			return
 		}
+		if s.Viewer {
+			r = asViewer(r)
+		}
 		o.next.ServeHTTP(w, r)
 		return
 	}
@@ -257,16 +268,16 @@ func (o *OIDC) handleCallback(w http.ResponseWriter, r *http.Request) {
 	}
 	http.SetCookie(w, &http.Cookie{Name: loginCookie + state, Path: "/", MaxAge: -1, HttpOnly: true, Secure: o.secure})
 
-	user, err := o.exchange(r, q.Get("code"), ls)
+	user, viewer, err := o.exchange(r, q.Get("code"), ls)
 	if err != nil {
 		log.Printf("oidc: login failed: %v", err)
 		http.Error(w, "login failed, see the LogStream logs", http.StatusForbidden)
 		return
 	}
-	log.Printf("oidc: %s logged in", user)
+	log.Printf("oidc: %s logged in (%s)", user, roleName(viewer))
 	http.SetCookie(w, &http.Cookie{
 		Name:     sessionCookie,
-		Value:    signCookie(o.key, session{User: user, Exp: time.Now().Add(o.cfg.sessionTTL).Unix()}),
+		Value:    signCookie(o.key, session{User: user, Exp: time.Now().Add(o.cfg.sessionTTL).Unix(), Viewer: viewer}),
 		Path:     "/",
 		MaxAge:   int(o.cfg.sessionTTL.Seconds()),
 		HttpOnly: true,
@@ -286,14 +297,15 @@ func (o *OIDC) handleLogout(w http.ResponseWriter, r *http.Request) {
 	http.Redirect(w, r, "/", http.StatusFound)
 }
 
-// exchange trades the code for tokens and returns the user name from the verified ID token.
-func (o *OIDC) exchange(r *http.Request, code string, ls loginState) (string, error) {
+// exchange trades the code for tokens and returns the user name from the verified ID
+// token, and whether the user is read-only (not in OIDC_ADMIN_GROUP).
+func (o *OIDC) exchange(r *http.Request, code string, ls loginState) (string, bool, error) {
 	if code == "" {
-		return "", errors.New("no code in the callback")
+		return "", false, errors.New("no code in the callback")
 	}
 	meta, err := o.discover()
 	if err != nil {
-		return "", err
+		return "", false, err
 	}
 	form := url.Values{
 		"grant_type":    {"authorization_code"},
@@ -309,7 +321,7 @@ func (o *OIDC) exchange(r *http.Request, code string, ls loginState) (string, er
 	}
 	req, err := http.NewRequestWithContext(r.Context(), http.MethodPost, meta.TokenEndpoint, strings.NewReader(form.Encode()))
 	if err != nil {
-		return "", err
+		return "", false, err
 	}
 	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	req.Header.Set("Accept", "application/json")
@@ -318,29 +330,53 @@ func (o *OIDC) exchange(r *http.Request, code string, ls loginState) (string, er
 	}
 	res, err := o.client.Do(req)
 	if err != nil {
-		return "", fmt.Errorf("token endpoint: %w", err)
+		return "", false, fmt.Errorf("token endpoint: %w", err)
 	}
 	defer res.Body.Close()
 	body, _ := io.ReadAll(io.LimitReader(res.Body, 1<<20))
 	if res.StatusCode != http.StatusOK {
-		return "", fmt.Errorf("token endpoint: %s: %s", res.Status, bytes.TrimSpace(body))
+		return "", false, fmt.Errorf("token endpoint: %s: %s", res.Status, bytes.TrimSpace(body))
 	}
 	var tok struct {
 		IDToken string `json:"id_token"`
 	}
 	if err := json.Unmarshal(body, &tok); err != nil || tok.IDToken == "" {
-		return "", errors.New("token endpoint: no id_token in the response")
+		return "", false, errors.New("token endpoint: no id_token in the response")
 	}
 	claims, err := o.verifyIDToken(tok.IDToken, ls.Nonce)
 	if err != nil {
-		return "", err
+		return "", false, err
 	}
+	viewer := o.cfg.adminGroup != "" && !hasGroup(claims[o.cfg.groupsClaim], o.cfg.adminGroup)
 	for _, k := range []string{"preferred_username", "email", "name", "sub"} {
 		if v, _ := claims[k].(string); v != "" {
-			return v, nil
+			return v, viewer, nil
 		}
 	}
-	return "", errors.New("id_token: no sub")
+	return "", false, errors.New("id_token: no sub")
+}
+
+// hasGroup tells whether the groups claim (a list, or a single string) holds
+// group; a leading "/" (Keycloak group paths) is ignored.
+func hasGroup(claim any, group string) bool {
+	group = strings.TrimPrefix(group, "/")
+	var groups []string
+	switch v := claim.(type) {
+	case string:
+		groups = strings.Fields(strings.ReplaceAll(v, ",", " "))
+	case []any:
+		for _, g := range v {
+			if s, ok := g.(string); ok {
+				groups = append(groups, s)
+			}
+		}
+	}
+	for _, g := range groups {
+		if strings.TrimPrefix(g, "/") == group {
+			return true
+		}
+	}
+	return false
 }
 
 // verifyIDToken checks the signature (keys from jwks_uri) and the claims of an ID token.

auth_local.go

@@ -23,6 +23,8 @@ var loginFailDelay = time.Second // slows down password guessing
 
 type Local struct {
 	user, pass string
+	viewerUser string // optional read-only account
+	viewerPass string
 	ttl        time.Duration
 	logo       string // LOGIN_LOGO, served at /auth/logo
 	key        []byte
@@ -32,14 +34,17 @@ type Local struct {
 func newLocal(c authConfig) *Local {
 	// The key depends on the credentials: changing AUTH_USER or AUTH_PASS ends every session.
 	m := hmac.New(sha256.New, sessionKey(c.dataDir))
-	m.Write([]byte("local\x00" + c.user + "\x00" + c.pass))
+	m.Write([]byte("local\x00" + c.user + "\x00" + c.pass + "\x00" + c.viewerUser + "\x00" + c.viewerPass))
 	if c.loginLogo != "" {
 		if _, err := os.Stat(c.loginLogo); err != nil {
 			log.Printf("auth: LOGIN_LOGO: %v", err)
 		}
 	}
 	log.Printf("local authentication enabled (user %s)", c.user)
-	return &Local{user: c.user, pass: c.pass, ttl: c.sessionTTL, logo: c.loginLogo, key: m.Sum(nil)}
+	if c.viewerUser != "" {
+		log.Printf("local read-only account enabled (user %s)", c.viewerUser)
+	}
+	return &Local{user: c.user, pass: c.pass, viewerUser: c.viewerUser, viewerPass: c.viewerPass, ttl: c.sessionTTL, logo: c.loginLogo, key: m.Sum(nil)}
 }
 
 func (l *Local) ServeHTTP(w http.ResponseWriter, r *http.Request) {
@@ -58,12 +63,17 @@ func (l *Local) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		http.Redirect(w, r, loginPage, http.StatusFound)
 		return
 	}
-	user, ok := l.sessionUser(r)
+	s, ok := l.sessionUser(r)
 	if !ok {
-		if u, p, basic := r.BasicAuth(); basic && l.check(u, p) {
-			user, ok = u, true
+		if u, p, basic := r.BasicAuth(); basic {
+			if viewer, valid := l.check(u, p); valid {
+				s, ok = session{User: u, Viewer: viewer}, true
+			}
 		}
 	}
+	if ok && s.Viewer {
+		r = asViewer(r)
+	}
 	switch {
 	case r.URL.Path == loginPage:
 		if ok {
@@ -73,7 +83,7 @@ func (l *Local) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		w.Header().Set("Cache-Control", "no-store")
 		l.next.ServeHTTP(w, r)
 	case ok && r.URL.Path == "/auth/me":
-		writeJSON(w, http.StatusOK, map[string]string{"mode": "local", "user": user})
+		writeJSON(w, http.StatusOK, map[string]string{"mode": "local", "user": s.User, "role": roleName(s.Viewer)})
 	case ok:
 		l.next.ServeHTTP(w, r)
 	case r.Method == http.MethodGet && !strings.HasPrefix(r.URL.Path, "/api/") && r.URL.Path != "/auth/me":
@@ -94,7 +104,8 @@ func (l *Local) handleLogin(w http.ResponseWriter, r *http.Request) {
 	}
 	user, pass := r.PostFormValue("user"), r.PostFormValue("pass")
 	ret := safeReturn(r.PostFormValue("r"))
-	if !l.check(user, pass) {
+	viewer, valid := l.check(user, pass)
+	if !valid {
 		log.Printf("auth: failed login for %q from %s", user, clientIP(r))
 		time.Sleep(loginFailDelay)
 		q := url.Values{"e": {"1"}}
@@ -104,10 +115,10 @@ func (l *Local) handleLogin(w http.ResponseWriter, r *http.Request) {
 		http.Redirect(w, r, loginPage+"?"+q.Encode(), http.StatusSeeOther)
 		return
 	}
-	log.Printf("auth: %s logged in from %s", user, clientIP(r))
+	log.Printf("auth: %s logged in from %s (%s)", user, clientIP(r), roleName(viewer))
 	http.SetCookie(w, &http.Cookie{
 		Name:     sessionCookie,
-		Value:    signCookie(l.key, session{User: user, Exp: time.Now().Add(l.ttl).Unix()}),
+		Value:    signCookie(l.key, session{User: user, Exp: time.Now().Add(l.ttl).Unix(), Viewer: viewer}),
 		Path:     "/",
 		MaxAge:   int(l.ttl.Seconds()),
 		HttpOnly: true,
@@ -117,19 +128,30 @@ func (l *Local) handleLogin(w http.ResponseWriter, r *http.Request) {
 	http.Redirect(w, r, ret, http.StatusSeeOther)
 }
 
-func (l *Local) sessionUser(r *http.Request) (string, bool) {
+func (l *Local) sessionUser(r *http.Request) (session, bool) {
 	var s session
 	c, err := r.Cookie(sessionCookie)
 	if err != nil || !verifyCookie(l.key, c.Value, &s) || time.Now().Unix() >= s.Exp {
-		return "", false
+		return session{}, false
 	}
-	return s.User, true
+	return s, true
 }
 
-func (l *Local) check(user, pass string) bool {
-	u := subtle.ConstantTimeCompare([]byte(user), []byte(l.user))
-	p := subtle.ConstantTimeCompare([]byte(pass), []byte(l.pass))
-	return u&p == 1
+// check validates a user and password: the admin account, or the read-only one
+// (viewer=true) when AUTH_VIEWER_USER is set.
+func (l *Local) check(user, pass string) (viewer, ok bool) {
+	if same(user, l.user) && same(pass, l.pass) {
+		return false, true
+	}
+	if l.viewerUser != "" && same(user, l.viewerUser) && same(pass, l.viewerPass) {
+		return true, true
+	}
+	return false, false
+}
+
+// same compares in constant time, so the answer time says nothing of the secret.
+func same(a, b string) bool {
+	return subtle.ConstantTimeCompare([]byte(a), []byte(b)) == 1
 }
 
 // serveLogo sends LOGIN_LOGO; without it the login page hides the image.

dbstats.go

@@ -0,0 +1,167 @@
+package main
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// DBStats describes what VictoriaLogs holds (Settings > Data). Sizes are in
+// bytes; a field VictoriaLogs did not give stays at its zero value.
+type DBStats struct {
+	Rows       int64  `json:"rows"`       // stored log lines
+	DiskBytes  int64  `json:"diskBytes"`  // compressed data + index, on disk
+	IndexBytes int64  `json:"indexBytes"` // index part of DiskBytes
+	RawBytes   int64  `json:"rawBytes"`   // data before compression
+	FreeBytes  int64  `json:"freeBytes"`  // free space on the VictoriaLogs volume
+	Days       int64  `json:"days"`       // per-day partitions
+	Retention  string `json:"retention"`  // -retentionPeriod, e.g. "30d"
+	Oldest     string `json:"oldest,omitempty"`
+	Newest     string `json:"newest,omitempty"`
+	Last1h     int64  `json:"last1h"`
+	Last24h    int64  `json:"last24h"`
+	Hosts      int64  `json:"hosts"`
+	Apps       int64  `json:"apps"`
+	QueryError string `json:"queryError,omitempty"` // the LogsQL part failed, the metrics are still valid
+	Updated    string `json:"updated"`
+}
+
+// dbStatsCache keeps the last answer for a while: the LogsQL part reads the
+// whole base, which is too heavy to repeat each time the tab is opened.
+type dbStatsCache struct {
+	mu   sync.Mutex
+	at   time.Time
+	last *DBStats
+}
+
+const dbStatsTTL = 30 * time.Second
+
+func (c *dbStatsCache) get(ctx context.Context, s *Store, force bool) (*DBStats, error) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.last != nil && !force && time.Since(c.at) < dbStatsTTL {
+		return c.last, nil
+	}
+	st, err := s.DBStats(ctx)
+	if err != nil {
+		return nil, err
+	}
+	c.last, c.at = st, time.Now()
+	return st, nil
+}
+
+// DBStats reads the storage metrics of VictoriaLogs (/metrics), then counts
+// with LogsQL what the metrics do not tell (period, recent volume, sources).
+func (s *Store) DBStats(ctx context.Context) (*DBStats, error) {
+	st, err := s.storageMetrics(ctx)
+	if err != nil {
+		return nil, err
+	}
+	st.Updated = time.Now().UTC().Format(time.RFC3339)
+	if st.Rows == 0 {
+		return st, nil
+	}
+
+	qctx, cancel := context.WithTimeout(ctx, 20*time.Second)
+	defer cancel()
+	rows, err := s.Query(qctx, "* | stats min(_time) oldest, max(_time) newest, count_uniq(host) hosts, count_uniq(app) apps")
+	if err == nil && len(rows) > 0 {
+		r := rows[0]
+		st.Oldest, _ = r["oldest"].(string)
+		st.Newest, _ = r["newest"].(string)
+		st.Hosts, st.Apps = toInt(r["hosts"]), toInt(r["apps"])
+		rows, err = s.Query(qctx, "_time:24h | stats count() last24h, count() if (_time:1h) last1h")
+		if err == nil && len(rows) > 0 {
+			st.Last24h, st.Last1h = toInt(rows[0]["last24h"]), toInt(rows[0]["last1h"])
+		}
+	}
+	if err != nil {
+		st.QueryError = err.Error()
+	}
+	return st, nil
+}
+
+func (s *Store) storageMetrics(ctx context.Context) (*DBStats, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, s.base+"/metrics", nil)
+	if err != nil {
+		return nil, err
+	}
+	resp, err := s.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		msg, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
+		return nil, fmt.Errorf("VictoriaLogs /metrics: HTTP %d: %s", resp.StatusCode, strings.TrimSpace(string(msg)))
+	}
+	return parseStorageMetrics(resp.Body)
+}
+
+// parseStorageMetrics picks the storage figures out of the Prometheus text
+// format of VictoriaLogs' /metrics (app/vlstorage).
+func parseStorageMetrics(r io.Reader) (*DBStats, error) {
+	st := &DBStats{}
+	sc := bufio.NewScanner(r)
+	sc.Buffer(make([]byte, 64*1024), 1<<20)
+	for sc.Scan() {
+		line := sc.Text()
+		if line == "" || line[0] == '#' {
+			continue
+		}
+		name, labels, value := splitMetric(line)
+		switch name {
+		case "vl_storage_rows":
+			st.Rows += int64(value)
+		case "vl_data_size_bytes":
+			st.DiskBytes += int64(value)
+			if labels["type"] == "indexdb" {
+				st.IndexBytes += int64(value)
+			}
+		case "vl_uncompressed_data_size_bytes":
+			st.RawBytes += int64(value)
+		case "vl_free_disk_space_bytes":
+			st.FreeBytes = int64(value)
+		case "vl_partitions":
+			st.Days = int64(value)
+		case "flag":
+			if labels["name"] == "retentionPeriod" {
+				st.Retention = labels["value"]
+			}
+		}
+	}
+	return st, sc.Err()
+}
+
+// splitMetric splits `name{a="x",b="y"} 12` into its parts. Label values with
+// escaped quotes are not expected in the metrics read here.
+func splitMetric(line string) (string, map[string]string, float64) {
+	sp := strings.LastIndexByte(line, ' ')
+	if sp < 0 {
+		return "", nil, 0
+	}
+	value, _ := strconv.ParseFloat(line[sp+1:], 64)
+	head := line[:sp]
+	name, rest, ok := strings.Cut(head, "{")
+	if !ok {
+		return head, nil, value
+	}
+	labels := map[string]string{}
+	rest = strings.TrimSuffix(rest, "}")
+	for rest != "" {
+		k, v, ok := strings.Cut(rest, `="`)
+		if !ok {
+			break
+		}
+		val, after, _ := strings.Cut(v, `"`)
+		labels[strings.TrimSpace(k)] = val
+		rest = strings.TrimPrefix(after, ",")
+	}
+	return name, labels, value
+}

dbstats_test.go

@@ -0,0 +1,89 @@
+package main
+
+import (
+	"encoding/json"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Excerpt of VictoriaLogs v1.52 /metrics.
+const vlMetrics = `# a comment
+vl_free_disk_space_bytes{path="/vlogs"} 52428800000
+vl_storage_rows{type="storage/inmemory"} 120
+vl_storage_rows{type="storage/small"} 3000
+vl_storage_rows{type="storage/big"} 1000000
+vl_partitions 12
+vl_data_size_bytes{type="indexdb"} 2048
+vl_data_size_bytes{type="storage"} 1048576
+vl_compressed_data_size_bytes{type="storage/big"} 1000000
+vl_uncompressed_data_size_bytes{type="storage/inmemory"} 4096
+vl_uncompressed_data_size_bytes{type="storage/small"} 100000
+vl_uncompressed_data_size_bytes{type="storage/big"} 20000000
+flag{name="retentionPeriod", value="30d", is_set="true"} 1
+flag{name="httpListenAddr", value=":9428", is_set="true"} 1
+`
+
+func TestParseStorageMetrics(t *testing.T) {
+	st, err := parseStorageMetrics(strings.NewReader(vlMetrics))
+	if err != nil {
+		t.Fatal(err)
+	}
+	want := DBStats{Rows: 1003120, DiskBytes: 1050624, IndexBytes: 2048, RawBytes: 20104096, FreeBytes: 52428800000, Days: 12, Retention: "30d"}
+	if *st != want {
+		t.Fatalf("got %+v\nwant %+v", *st, want)
+	}
+}
+
+// statsVL answers /metrics and the LogsQL queries of DBStats.
+type statsVL struct{ queries int }
+
+func (v *statsVL) RoundTrip(r *http.Request) (*http.Response, error) {
+	body := vlMetrics
+	if r.URL.Path == "/select/logsql/query" {
+		v.queries++
+		_ = r.ParseForm()
+		if strings.HasPrefix(r.PostForm.Get("query"), "_time:24h") {
+			body = `{"last24h":"5000","last1h":"300"}` + "\n"
+		} else {
+			body = `{"oldest":"2026-09-21T08:00:00Z","newest":"2026-10-03T15:00:00Z","hosts":"4","apps":"17"}` + "\n"
+		}
+	}
+	return &http.Response{StatusCode: http.StatusOK, Body: io.NopCloser(strings.NewReader(body)), Header: http.Header{}}, nil
+}
+
+func TestDBStatsHandler(t *testing.T) {
+	vl := &statsVL{}
+	store := NewStore("http://vl", 10, 10, time.Second, nil)
+	store.client.Transport = vl
+	store.streamClient.Transport = vl
+	a := &API{store: store}
+
+	get := func(url string) DBStats {
+		rec := httptest.NewRecorder()
+		a.dbStats(rec, httptest.NewRequest("GET", url, nil))
+		if rec.Code != http.StatusOK {
+			t.Fatalf("status %d: %s", rec.Code, rec.Body)
+		}
+		var st DBStats
+		if err := json.Unmarshal(rec.Body.Bytes(), &st); err != nil {
+			t.Fatal(err)
+		}
+		return st
+	}
+	st := get("/api/dbstats")
+	if st.Rows != 1003120 || st.Oldest != "2026-09-21T08:00:00Z" || st.Hosts != 4 || st.Apps != 17 || st.Last24h != 5000 || st.Last1h != 300 || st.QueryError != "" {
+		t.Fatalf("unexpected stats: %+v", st)
+	}
+	get("/api/dbstats")
+	if vl.queries != 2 {
+		t.Fatalf("second call within the TTL should be cached, got %d queries", vl.queries)
+	}
+	get("/api/dbstats?refresh=1")
+	if vl.queries != 4 {
+		t.Fatalf("refresh=1 should query again, got %d queries", vl.queries)
+	}
+}

dmesg.go

@@ -0,0 +1,481 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+	"unicode/utf8"
+)
+
+// dmesgConfig is saved in /data/dmesg.json and edited in Settings > Sources.
+type dmesgConfig struct {
+	Enabled bool `json:"enabled"`
+}
+
+// dmesgPos is where reading resumes: the last record sent, valid for one boot
+// only (the kernel numbers its records from 0 at each boot).
+type dmesgPos struct {
+	BootID string `json:"boot_id"`
+	Seq    uint64 `json:"seq"`
+}
+
+// Dmesg collects the kernel ring buffer of the machine hosting the stack by
+// reading /dev/kmsg, the device dmesg itself reads.
+type Dmesg struct {
+	device     string // /dev/kmsg
+	bootIDPath string // identifies the current boot
+	uptimePath string // gives the boot time, to date the records
+	sink       func(*Entry)
+	backfill   time.Duration
+	cfgPath    string
+	statePath  string
+	retry      time.Duration // delay before opening the device again after a failure
+	wake       chan struct{}
+
+	mu        sync.Mutex
+	cfg       dmesgConfig
+	reset     bool
+	pos       dmesgPos
+	dirty     bool
+	open      bool
+	read      uint64
+	lost      uint64
+	errCode   string
+	errDetail string
+}
+
+func NewDmesg(device, dataDir string, backfill time.Duration, sink func(*Entry)) *Dmesg {
+	d := &Dmesg{
+		device:     device,
+		bootIDPath: "/proc/sys/kernel/random/boot_id",
+		uptimePath: "/proc/uptime",
+		sink:       sink,
+		backfill:   backfill,
+		cfgPath:    filepath.Join(dataDir, "dmesg.json"),
+		statePath:  filepath.Join(dataDir, "dmesg-state.json"),
+		retry:      10 * time.Second,
+		wake:       make(chan struct{}, 1),
+	}
+	if b, err := os.ReadFile(d.cfgPath); err == nil {
+		_ = json.Unmarshal(b, &d.cfg)
+	}
+	if b, err := os.ReadFile(d.statePath); err == nil {
+		_ = json.Unmarshal(b, &d.pos)
+	}
+	return d
+}
+
+// kmsgSession is one opening of the device, read by its own goroutine.
+type kmsgSession struct {
+	f       *os.File
+	done    chan struct{}
+	err     error
+	stopped bool // closed on purpose: err is not a failure
+}
+
+func (s *kmsgSession) stop() {
+	s.stopped = true
+	s.f.Close() // ends a pending read (/dev/kmsg goes through the poller)
+	select {
+	case <-s.done:
+	case <-time.After(2 * time.Second):
+	}
+}
+
+// Run keeps the device open while the source is enabled.
+func (d *Dmesg) Run(ctx context.Context) {
+	save := time.NewTicker(5 * time.Second)
+	defer save.Stop()
+	var cur *kmsgSession
+	var retryAt time.Time
+	for {
+		d.mu.Lock()
+		enabled, reset := d.cfg.Enabled, d.reset
+		d.reset = false
+		d.mu.Unlock()
+		if reset {
+			// Disabled then enabled again: start over from DMESG_BACKFILL ago
+			// rather than reading everything logged in between.
+			if cur != nil {
+				cur.stop()
+				cur = nil
+			}
+			d.mu.Lock()
+			d.pos, d.dirty = dmesgPos{}, true
+			d.mu.Unlock()
+			d.saveState()
+			retryAt = time.Time{}
+		}
+		if !enabled && cur != nil {
+			cur.stop()
+			cur = nil
+			d.mu.Lock()
+			d.open = false
+			d.mu.Unlock()
+		}
+		if enabled && cur == nil && !time.Now().Before(retryAt) {
+			var err error
+			if cur, err = d.start(); err != nil {
+				d.fail(err)
+				retryAt = time.Now().Add(d.retry)
+			}
+		}
+		var done chan struct{}
+		if cur != nil {
+			done = cur.done
+		}
+		wait := d.retry
+		if cur == nil && enabled {
+			wait = max(time.Until(retryAt), 10*time.Millisecond)
+		}
+		timer := time.NewTimer(wait)
+		select {
+		case <-ctx.Done():
+			timer.Stop()
+			if cur != nil {
+				cur.stop()
+			}
+			d.saveState()
+			return
+		case <-d.wake:
+		case <-save.C:
+			d.saveState()
+		case <-timer.C:
+		case <-done:
+			if !cur.stopped {
+				d.fail(cur.err)
+			}
+			cur = nil
+			retryAt = time.Now().Add(d.retry)
+		}
+		timer.Stop()
+	}
+}
+
+func (d *Dmesg) saveState() {
+	d.mu.Lock()
+	if !d.dirty {
+		d.mu.Unlock()
+		return
+	}
+	d.dirty = false
+	pos := d.pos
+	d.mu.Unlock()
+	if err := writeJSONFile(d.statePath, pos); err != nil {
+		logEvent("dmesg", 4, "saving position: %v", err)
+	}
+}
+
+// fail records why the device is not being read (nil error: end of a
+// regular file, only seen in tests).
+func (d *Dmesg) fail(err error) {
+	code, detail := "", ""
+	if err != nil && !errors.Is(err, io.EOF) {
+		detail = err.Error()
+		switch {
+		case errors.Is(err, fs.ErrNotExist):
+			code = "not_found"
+		case errors.Is(err, fs.ErrPermission):
+			code = "permission"
+		default:
+			code = "read"
+		}
+	}
+	d.mu.Lock()
+	changed := code != d.errCode
+	d.open, d.errCode, d.errDetail = false, code, detail
+	d.mu.Unlock()
+	if changed && code != "" {
+		logEvent("dmesg", 4, "cannot read the kernel messages: %v", err)
+	}
+}
+
+// start opens the device and starts reading it in the background.
+func (d *Dmesg) start() (*kmsgSession, error) {
+	f, err := os.Open(d.device)
+	if err != nil {
+		return nil, err
+	}
+	bootID := readTrim(d.bootIDPath)
+	boot := d.bootTime(time.Now())
+	d.mu.Lock()
+	pos := d.pos
+	d.open, d.errCode, d.errDetail = true, "", ""
+	d.mu.Unlock()
+
+	// Same boot as the saved position: skip what was already sent. Otherwise
+	// read from DMESG_BACKFILL ago (0: only new records).
+	resume := pos.BootID != "" && pos.BootID == bootID
+	var notBefore time.Time
+	if !resume {
+		if d.backfill <= 0 {
+			if _, err := f.Seek(0, io.SeekEnd); err != nil {
+				f.Close()
+				return nil, err
+			}
+		} else if !boot.IsZero() {
+			notBefore = time.Now().Add(-d.backfill)
+		}
+		d.mu.Lock()
+		d.pos, d.dirty = dmesgPos{BootID: bootID}, true
+		d.mu.Unlock()
+	}
+	s := &kmsgSession{f: f, done: make(chan struct{})}
+	go func() {
+		defer close(s.done)
+		s.err = d.consume(f, bootID, boot, resume, pos.Seq, notBefore)
+	}()
+	return s, nil
+}
+
+func readTrim(path string) string {
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSpace(string(b))
+}
+
+// bootTime is now minus the uptime; zero when unknown (records are then dated
+// when they are read).
+func (d *Dmesg) bootTime(now time.Time) time.Time {
+	f := strings.Fields(readTrim(d.uptimePath))
+	if len(f) == 0 {
+		return time.Time{}
+	}
+	up, err := strconv.ParseFloat(f[0], 64)
+	if err != nil || up <= 0 {
+		return time.Time{}
+	}
+	return now.Add(-time.Duration(up * float64(time.Second)))
+}
+
+// consume reads records until an error. Each read of /dev/kmsg returns one
+// record; several records in one read (a regular file, in tests) are split.
+func (d *Dmesg) consume(r io.Reader, bootID string, boot time.Time, resume bool, after uint64, notBefore time.Time) error {
+	buf := make([]byte, 64<<10) // a record is at most 8 KiB
+	last, haveLast := after, resume
+	for {
+		n, err := r.Read(buf)
+		if n > 0 {
+			for _, raw := range splitKmsg(buf[:n]) {
+				rec, ok := parseKmsg(raw)
+				if !ok {
+					continue
+				}
+				if haveLast && rec.Seq <= last {
+					continue // already sent before a restart
+				}
+				var lost uint64
+				if haveLast && rec.Seq > last+1 {
+					lost = rec.Seq - last - 1 // overwritten in the ring buffer before being read
+				}
+				last, haveLast = rec.Seq, true
+				now := time.Now()
+				t := now
+				if !boot.IsZero() {
+					t = boot.Add(time.Duration(rec.Usec) * time.Microsecond)
+				}
+				if !notBefore.IsZero() && t.Before(notBefore) {
+					d.advance(bootID, rec.Seq, 0, 0)
+					continue
+				}
+				d.sink(kmsgEntry(rec, t, now))
+				d.advance(bootID, rec.Seq, 1, lost)
+			}
+		}
+		if err != nil {
+			if errors.Is(err, os.ErrClosed) {
+				return nil
+			}
+			if errors.Is(err, syscall.EPIPE) {
+				continue // records overwritten while reading: the next read goes on
+			}
+			return err
+		}
+	}
+}
+
+func (d *Dmesg) advance(bootID string, seq, read, lost uint64) {
+	d.mu.Lock()
+	d.pos, d.dirty = dmesgPos{BootID: bootID, Seq: seq}, true
+	d.read += read
+	d.lost += lost
+	d.mu.Unlock()
+}
+
+// kmsgRecord is one record of /dev/kmsg:
+//
+//	prio,seq,usec,flags[,...];message
+//	 KEY=value          (optional dictionary lines)
+type kmsgRecord struct {
+	Prio int
+	Seq  uint64
+	Usec uint64
+	Msg  string
+	Dict map[string]string
+}
+
+// splitKmsg cuts a buffer into records: a new record starts after a newline
+// that is not followed by a space (dictionary lines start with one).
+func splitKmsg(b []byte) [][]byte {
+	var out [][]byte
+	start := 0
+	for i := 0; i < len(b); i++ {
+		if b[i] == '\n' && (i+1 == len(b) || b[i+1] != ' ') {
+			out = append(out, b[start:i])
+			start = i + 1
+		}
+	}
+	if start < len(b) {
+		out = append(out, b[start:])
+	}
+	return out
+}
+
+func parseKmsg(raw []byte) (kmsgRecord, bool) {
+	var rec kmsgRecord
+	lines := bytes.Split(raw, []byte{'\n'})
+	head, msg, ok := bytes.Cut(lines[0], []byte{';'})
+	if !ok {
+		return rec, false
+	}
+	f := strings.Split(string(head), ",")
+	if len(f) < 3 {
+		return rec, false
+	}
+	prio, err1 := strconv.Atoi(f[0])
+	seq, err2 := strconv.ParseUint(f[1], 10, 64)
+	usec, err3 := strconv.ParseUint(f[2], 10, 64)
+	if err1 != nil || err2 != nil || err3 != nil || prio < 0 {
+		return rec, false
+	}
+	rec.Prio, rec.Seq, rec.Usec = prio, seq, usec
+	rec.Msg = unescapeKmsg(string(msg))
+	for _, l := range lines[1:] {
+		if k, v, ok := strings.Cut(strings.TrimPrefix(string(l), " "), "="); ok && k != "" {
+			if rec.Dict == nil {
+				rec.Dict = map[string]string{}
+			}
+			rec.Dict[k] = unescapeKmsg(v)
+		}
+	}
+	return rec, true
+}
+
+// unescapeKmsg decodes the \xNN escapes the kernel uses for non-printable bytes.
+func unescapeKmsg(s string) string {
+	if !strings.Contains(s, `\x`) {
+		return s
+	}
+	var b strings.Builder
+	for i := 0; i < len(s); i++ {
+		if s[i] == '\\' && i+3 < len(s) && s[i+1] == 'x' {
+			if v, err := strconv.ParseUint(s[i+2:i+4], 16, 8); err == nil {
+				b.WriteByte(byte(v))
+				i += 3
+				continue
+			}
+		}
+		b.WriteByte(s[i])
+	}
+	return b.String()
+}
+
+// kmsgEntry turns a record into an Entry. Kernel records have the kern
+// facility; programs writing to /dev/kmsg (systemd at boot…) use another
+// one and prefix their name: "systemd[1]: …".
+func kmsgEntry(rec kmsgRecord, t, now time.Time) *Entry {
+	sev := rec.Prio & 7
+	fac := rec.Prio >> 3
+	if fac >= len(facilityNames) {
+		fac = 1 // user
+	}
+	msg := strings.TrimRight(rec.Msg, "\n")
+	if !utf8.ValidString(msg) {
+		msg = strings.ToValidUTF8(msg, "�")
+	}
+	app, pid := "kernel", ""
+	if fac != 0 {
+		if a, p, rest, ok := splitTag(msg); ok {
+			app, pid, msg = a, p, rest
+		}
+	}
+	e := &Entry{
+		Time:       t,
+		Received:   now,
+		Host:       "localhost",
+		App:        app,
+		ProcID:     pid,
+		Facility:   facilityNames[fac],
+		Severity:   severityNames[sev],
+		SevNum:     sev,
+		Message:    msg,
+		Proto:      "kmsg",
+		SourceType: "kernel",
+		Wait:       true,
+	}
+	if s, dev := rec.Dict["SUBSYSTEM"], rec.Dict["DEVICE"]; s != "" || dev != "" {
+		e.Extra = map[string]string{}
+		if s != "" {
+			e.Extra["subsystem"] = s
+		}
+		if dev != "" {
+			e.Extra["device"] = dev
+		}
+	}
+	return e
+}
+
+// splitTag cuts "name[pid]: message" or "name: message".
+func splitTag(msg string) (app, pid, rest string, ok bool) {
+	tag, rest, found := strings.Cut(msg, ": ")
+	if !found || tag == "" || len(tag) > 48 || strings.ContainsAny(tag, " \t") {
+		return "", "", "", false
+	}
+	if i := strings.IndexByte(tag, '['); i > 0 && strings.HasSuffix(tag, "]") {
+		return tag[:i], tag[i+1 : len(tag)-1], rest, true
+	}
+	return tag, "", rest, true
+}
+
+// Configure saves and applies the configuration.
+func (d *Dmesg) Configure(cfg dmesgConfig) error {
+	d.mu.Lock()
+	if d.cfg.Enabled && !cfg.Enabled {
+		d.reset = true
+		d.errCode, d.errDetail = "", ""
+	}
+	d.cfg = cfg
+	d.mu.Unlock()
+	select {
+	case d.wake <- struct{}{}:
+	default:
+	}
+	return writeJSONFile(d.cfgPath, cfg)
+}
+
+// Status is the state shown in Settings > Sources.
+func (d *Dmesg) Status() map[string]any {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	return map[string]any{
+		"enabled": d.cfg.Enabled,
+		"open":    d.open && d.cfg.Enabled,
+		"device":  d.device,
+		"read":    d.read,
+		"lost":    d.lost,
+		"code":    d.errCode,
+		"error":   d.errDetail,
+	}
+}

dmesg_test.go

@@ -0,0 +1,265 @@
+package main
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestParseKmsg(t *testing.T) {
+	rec, ok := parseKmsg([]byte("6,339,5140900,-;NET: Registered protocol family 10\n SUBSYSTEM=net\n DEVICE=n2"))
+	if !ok || rec.Prio != 6 || rec.Seq != 339 || rec.Usec != 5140900 || rec.Msg != "NET: Registered protocol family 10" {
+		t.Fatalf("record %+v", rec)
+	}
+	if rec.Dict["SUBSYSTEM"] != "net" || rec.Dict["DEVICE"] != "n2" {
+		t.Fatalf("dict %+v", rec.Dict)
+	}
+	// Extra header fields (newer kernels: caller id) and a ';' in the message.
+	rec, ok = parseKmsg([]byte("4,12,99,c,caller=T1;a;b \\x1b[31mred\\x5c"))
+	if !ok || rec.Seq != 12 || rec.Msg != "a;b \x1b[31mred\\" {
+		t.Fatalf("record %+v", rec)
+	}
+	for _, bad := range []string{"", "no header", "6,1;short", "x,1,2,-;msg", "6,-1,2,-;msg", "-1,1,2,-;msg"} {
+		if _, ok := parseKmsg([]byte(bad)); ok {
+			t.Errorf("%q parsed", bad)
+		}
+	}
+}
+
+func TestUnescapeKmsg(t *testing.T) {
+	for in, want := range map[string]string{
+		`plain`:       "plain",
+		`a\x0ab`:      "a\nb",
+		`end\x4`:      `end\x4`,
+		`bad\xzz`:     `bad\xzz`,
+		`\x41\x42\x4`: `AB\x4`,
+	} {
+		if got := unescapeKmsg(in); got != want {
+			t.Errorf("%q: got %q, want %q", in, got, want)
+		}
+	}
+}
+
+func TestSplitKmsg(t *testing.T) {
+	got := splitKmsg([]byte("6,1,0,-;one\n SUBSYSTEM=pci\n6,2,0,-;two\n6,3,0,-;three"))
+	if len(got) != 3 || string(got[0]) != "6,1,0,-;one\n SUBSYSTEM=pci" || string(got[2]) != "6,3,0,-;three" {
+		t.Fatalf("got %q", got)
+	}
+}
+
+func TestKmsgEntry(t *testing.T) {
+	boot := time.Date(2026, 10, 4, 6, 0, 0, 0, time.UTC)
+	now := boot.Add(time.Hour)
+	rec, _ := parseKmsg([]byte("3,7,2500000,-;usb 1-1: device descriptor read/64, error -71\n SUBSYSTEM=usb\n DEVICE=c189:1"))
+	e := kmsgEntry(rec, boot.Add(2500*time.Millisecond), now)
+	if e.App != "kernel" || e.Facility != "kern" || e.Severity != "err" || e.SevNum != 3 || e.SourceType != "kernel" || e.Proto != "kmsg" || !e.Wait {
+		t.Fatalf("entry %+v", e)
+	}
+	if e.Message != "usb 1-1: device descriptor read/64, error -71" || e.Extra["subsystem"] != "usb" || e.Extra["device"] != "c189:1" {
+		t.Fatalf("entry %+v", e)
+	}
+	if !e.Time.Equal(boot.Add(2500*time.Millisecond)) || !e.Received.Equal(now) {
+		t.Fatalf("times %v %v", e.Time, e.Received)
+	}
+	// Written by a program (facility daemon = 3<<3 | info).
+	rec, _ = parseKmsg([]byte("30,8,3000000,-;systemd[1]: Started Journal Service."))
+	e = kmsgEntry(rec, now, now)
+	if e.App != "systemd" || e.ProcID != "1" || e.Facility != "daemon" || e.Severity != "info" || e.Message != "Started Journal Service." || e.Extra != nil {
+		t.Fatalf("entry %+v", e)
+	}
+	// Facility out of range.
+	rec, _ = parseKmsg([]byte("255,9,0,-;odd"))
+	if e = kmsgEntry(rec, now, now); e.Facility != "user" || e.Severity != "debug" {
+		t.Fatalf("entry %+v", e)
+	}
+}
+
+// fakeHost writes a kmsg file, a boot id and an uptime in a temp dir.
+func fakeHost(t *testing.T, uptime float64, records ...string) (*Dmesg, *[]*Entry, *sync.Mutex) {
+	t.Helper()
+	dir := t.TempDir()
+	write := func(name, s string) string {
+		p := filepath.Join(dir, name)
+		if err := os.WriteFile(p, []byte(s), 0o644); err != nil {
+			t.Fatal(err)
+		}
+		return p
+	}
+	var mu sync.Mutex
+	var got []*Entry
+	d := NewDmesg(write("kmsg", strings.Join(records, "\n")+"\n"), filepath.Join(dir, "data"), time.Hour, func(e *Entry) {
+		mu.Lock()
+		got = append(got, e)
+		mu.Unlock()
+	})
+	d.bootIDPath = write("boot_id", "b1\n")
+	d.uptimePath = write("uptime", strconv.FormatFloat(uptime, 'f', 2, 64)+" 1234.00\n")
+	d.retry = 20 * time.Millisecond
+	return d, &got, &mu
+}
+
+func TestDmesgBackfillAndResume(t *testing.T) {
+	// Booted 3 h ago: the record at 1 s is outside the 1 h backfill window,
+	// the ones at 2.5 h and 2.9 h are inside.
+	d, got, mu := fakeHost(t, 3*3600,
+		"6,1,1000000,-;Linux version 6.12",
+		"4,2,9000000000,-;eth0: link down",
+		"6,3,10440000000,-;eth0: link up",
+	)
+	s, err := d.start()
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-s.done
+	mu.Lock()
+	if len(*got) != 2 || (*got)[0].Message != "eth0: link down" || (*got)[1].Message != "eth0: link up" {
+		t.Fatalf("got %+v", *got)
+	}
+	if age := time.Since((*got)[1].Time); age < 5*time.Minute || age > 7*time.Minute {
+		t.Fatalf("record dated %v ago", age)
+	}
+	mu.Unlock()
+	d.saveState()
+
+	// Restart with the saved position: same boot, nothing is sent again,
+	// and a new record is.
+	f, _ := os.OpenFile(d.device, os.O_APPEND|os.O_WRONLY, 0)
+	_, _ = f.WriteString("6,6,10500000000,-;eth0: renamed\n")
+	f.Close()
+	d2 := NewDmesg(d.device, filepath.Dir(d.statePath), time.Hour, d.sink)
+	d2.bootIDPath, d2.uptimePath = d.bootIDPath, d.uptimePath
+	if d2.pos != (dmesgPos{BootID: "b1", Seq: 3}) {
+		t.Fatalf("saved position %+v", d2.pos)
+	}
+	s, err = d2.start()
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-s.done
+	mu.Lock()
+	defer mu.Unlock()
+	if len(*got) != 3 || (*got)[2].Message != "eth0: renamed" || (*got)[2].App != "kernel" {
+		t.Fatalf("after restart %+v", (*got)[2:])
+	}
+	if st := d2.Status(); st["lost"] != uint64(2) || st["read"] != uint64(1) {
+		t.Fatalf("status %+v", st) // records 4 and 5 were overwritten
+	}
+}
+
+func TestDmesgNewBoot(t *testing.T) {
+	d, got, mu := fakeHost(t, 60, "6,1,1000000,-;booted")
+	d.pos = dmesgPos{BootID: "old", Seq: 500}
+	s, err := d.start()
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-s.done
+	mu.Lock()
+	defer mu.Unlock()
+	if len(*got) != 1 || d.pos != (dmesgPos{BootID: "b1", Seq: 1}) {
+		t.Fatalf("got %d entries, position %+v", len(*got), d.pos)
+	}
+}
+
+func TestDmesgNoBackfill(t *testing.T) {
+	d, got, mu := fakeHost(t, 60, "6,1,1000000,-;old")
+	d.backfill = 0
+	s, err := d.start()
+	if err != nil {
+		t.Fatal(err)
+	}
+	<-s.done
+	mu.Lock()
+	defer mu.Unlock()
+	if len(*got) != 0 {
+		t.Fatalf("got %+v", *got)
+	}
+}
+
+func TestDmesgRun(t *testing.T) {
+	d, got, mu := fakeHost(t, 60, "6,1,1000000,-;first", "6,2,2000000,-;second")
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() {
+		d.Run(ctx)
+		close(done)
+	}()
+	if err := d.Configure(dmesgConfig{Enabled: true}); err != nil {
+		t.Fatal(err)
+	}
+	deadline := time.Now().Add(5 * time.Second)
+	for {
+		mu.Lock()
+		n := len(*got)
+		mu.Unlock()
+		if n >= 2 {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("got %d entries", n)
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	// The file is re-opened after each end of file: still no duplicate.
+	time.Sleep(100 * time.Millisecond)
+	cancel()
+	<-done
+	mu.Lock()
+	defer mu.Unlock()
+	if len(*got) != 2 {
+		t.Fatalf("got %d entries", len(*got))
+	}
+	b, err := os.ReadFile(d.statePath)
+	if err != nil || !strings.Contains(string(b), `"seq": 2`) {
+		t.Fatalf("state %s %v", b, err)
+	}
+	b, _ = os.ReadFile(d.cfgPath)
+	if !strings.Contains(string(b), `"enabled": true`) {
+		t.Fatalf("config %s", b)
+	}
+}
+
+func TestDmesgMissingDevice(t *testing.T) {
+	d := NewDmesg(filepath.Join(t.TempDir(), "kmsg"), t.TempDir(), time.Hour, func(*Entry) {})
+	d.retry = 20 * time.Millisecond
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() {
+		d.Run(ctx)
+		close(done)
+	}()
+	_ = d.Configure(dmesgConfig{Enabled: true})
+	deadline := time.Now().Add(5 * time.Second)
+	for d.Status()["code"] != "not_found" {
+		if time.Now().After(deadline) {
+			t.Fatalf("status %+v", d.Status())
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	// Turning it off clears the error.
+	_ = d.Configure(dmesgConfig{Enabled: false})
+	if st := d.Status(); st["code"] != "" || st["enabled"] != false {
+		t.Fatalf("status %+v", st)
+	}
+	cancel()
+	<-done
+}
+
+func TestDmesgPermission(t *testing.T) {
+	if os.Geteuid() == 0 {
+		t.Skip("root reads everything")
+	}
+	p := filepath.Join(t.TempDir(), "kmsg")
+	_ = os.WriteFile(p, []byte("6,1,0,-;x\n"), 0o000)
+	d := NewDmesg(p, t.TempDir(), time.Hour, func(*Entry) {})
+	_, err := d.start()
+	d.fail(err)
+	if st := d.Status(); st["code"] != "permission" {
+		t.Fatalf("status %+v", st)
+	}
+}

docker-compose.yml

@@ -7,9 +7,9 @@ services:
       - victorialogs
       - docker-proxy
     ports:
-      - "${SYSLOG_PORT:-514}:5514/udp"
-      - "${SYSLOG_PORT:-514}:5514/tcp"
-      - "${HTTP_PORT:-8080}:8080"
+      - "${SYSLOG_PORT:-5514}:5514/udp"
+      - "${SYSLOG_PORT:-5514}:5514/tcp"
+      - "${HTTP_PORT:-8989}:8080"
     environment:
       VLOGS_URL: http://victorialogs:9428
       SYSLOG_PUBLIC_PORT: ${SYSLOG_PORT:-514}     # le port d'ecoute syslog par defaut (attention aux ports <1024)
@@ -17,30 +17,59 @@ services:
       AUTH_MODE: ${AUTH_MODE:-local}   # local (page de connexion, compte ci-dessous) ou oidc
       AUTH_USER: ${AUTH_USER:-}   # vide = pas d'authentification, on delegue ca au reverse proxy traefik
       AUTH_PASS: ${AUTH_PASS:-}
+      AUTH_VIEWER_USER: ${AUTH_VIEWER_USER:-}   # compte en lecture seule (optionnel)
+      AUTH_VIEWER_PASS: ${AUTH_VIEWER_PASS:-}
       LOGIN_LOGO: ${LOGIN_LOGO:-}     # PNG affiche sur la page de connexion (chemin dans le conteneur, voir volumes)
+      PRESETS_FILE: ${PRESETS_FILE:-} # prereglages de tags (defaut /data/presets.json, voir docs/presets.fr.md)
       OIDC_ISSUER: ${OIDC_ISSUER:-}
       OIDC_CLIENT_ID: ${OIDC_CLIENT_ID:-}
       OIDC_CLIENT_SECRET: ${OIDC_CLIENT_SECRET:-}
       OIDC_REDIRECT_URL: ${OIDC_REDIRECT_URL:-}
       OIDC_SCOPES: ${OIDC_SCOPES:-openid profile email}
+      OIDC_ADMIN_GROUP: ${OIDC_ADMIN_GROUP:-}     # vide = tout le monde est admin, sinon les autres sont en lecture seule
+      OIDC_GROUPS_CLAIM: ${OIDC_GROUPS_CLAIM:-groups}
       SESSION_TTL: ${SESSION_TTL:-${OIDC_SESSION_TTL:-12h}}   # duree de la session (local et oidc)
       RDNS: ${RDNS:-on}               # resol dns
       DNS_SERVER: ${DNS_SERVER:-}     # si resolv directe
-      ALLOW_PURGE: ${ALLOW_PURGE:-true}
+      ALLOW_PURGE: ${ALLOW_PURGE:-false}   # true pour autoriser « Supprimer tous les logs »
       EXPORT_MAX: ${EXPORT_MAX:-100000}
       DOCKER_LOGS: ${DOCKER_LOGS:-on}             # collecte des logs des conteneurs Docker
       DOCKER_HOST: tcp://docker-proxy:2375        # lecture seul de l'API Docker
       DOCKER_BACKFILL: ${DOCKER_BACKFILL:-1h}
       HOST_LOGS_BACKFILL: ${HOST_LOGS_BACKFILL:-1h}   # historique lu a l'activation des logs systeme de l'hote
+      DMESG_BACKFILL: ${DMESG_BACKFILL:-1h}   # historique lu a l'activation des messages du noyau (dmesg)
+      AUDIT_BACKFILL: ${AUDIT_BACKFILL:-1h}   # historique lu a l'activation de l'audit Linux (auditd)
+      FILES_BACKFILL: ${FILES_BACKFILL:-1h}   # historique lu a l'activation d'un fichier de logs (Reglages > Sources)
+      AUDIT_HOST: ${AUDIT_HOST:-}             # nom d'hote des evenements d'audit (vide : node= des enregistrements, sinon /host/etc/hostname)
     group_add:
       - "${HOST_LOGS_GID:-4}"        # groupe autorise a lire les logs de l'hote (4 = adm sur Debian/Ubuntu)
+    # messages du noyau de l'hote (dmesg), source a activer dans Reglages > Sources :
+    # decommenter devices pour donner /dev/kmsg (lecture seule) au conteneur
+    # devices:
+    #   - /dev/kmsg:/dev/kmsg:r
+    # si l'hote a kernel.dmesg_restrict=1 (defaut Debian/Ubuntu), soit sur l'hote :
+    #   sysctl -w kernel.dmesg_restrict=0   (et kernel.dmesg_restrict = 0 dans /etc/sysctl.d/ pour le garder)
+    # soit lancer le conteneur en root avec la capacite SYSLOG (decommenter les deux) :
+    # user: "0:0"
+    # cap_add:
+    #   - SYSLOG
     volumes:
       - logstream-data:/data         # tags.json, docker.json (les choix des conteneurs)
       # logs systeme de l'hote, en lecture seule (source a activer dans Reglages > Sources)
       - /var/log:/host/var/log:ro                     # journal systemd persistant et fichiers texte
       - /run/log/journal:/host/run/log/journal:ro     # journal systemd volatile
+      # audit Linux (auditd), source a activer dans Reglages > Sources ; le fichier doit etre
+      # lisible par l'UID 10001 : log_group = adm dans /etc/audit/auditd.conf (voir le README)
+      # - /var/log/audit:/var/log/audit:ro
+      # noms des utilisateurs et de l'hote pour les evenements d'audit (optionnel)
+      # - /etc/passwd:/host/etc/passwd:ro
+      # - /etc/hostname:/host/etc/hostname:ro
+      # fichiers de logs d'autres programmes (Traefik, nginx...), a declarer dans Reglages > Sources > Fichiers de logs
+      # - /var/log/traefik:/logs/traefik:ro
       # logo de la page de connexion, avec LOGIN_LOGO=/config/logo.png dans .env
       # - ./logo.png:/config/logo.png:ro
+      # prereglages de tags personnalises, avec PRESETS_FILE=/config/presets.json dans .env
+      # - ./presets.json:/config/presets.json:ro
     labels:
       logstream.exclude: "true"      # pas de collect des logs logstream
 

docker.go

@@ -61,8 +61,8 @@ type DockerManager struct {
 	cfg        dockerConfig
 	hostName   string
 	containers []DockerContainer
-	followers  map[string]*follower  // container ID -> running follower
-	checkpoint map[string]time.Time // container ID -> timestamp of the last line read
+	followers  map[string]*follower // container ID -> running follower
+	checkpoint map[string]time.Time // container ID -> timestamp of the last line stored
 	dirty      bool
 	connected  bool
 	lastErr    string
@@ -242,7 +242,7 @@ func (m *DockerManager) setError(err error) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	if m.lastErr != err.Error() {
-		log.Printf("docker: %v", err)
+		logEvent("docker", 3, "Docker API unreachable: %v", err)
 	}
 	m.connected = false
 	m.lastErr = err.Error()
@@ -290,7 +290,7 @@ func (m *DockerManager) sync(ctx context.Context) {
 	m.mu.Lock()
 	defer m.mu.Unlock()
 	if !m.connected {
-		log.Printf("docker: connected, %d containers", len(list))
+		logEvent("docker", 6, "connected to the Docker API, %d containers", len(list))
 	}
 	m.connected, m.lastErr = true, ""
 	seen := map[string]bool{}
@@ -371,7 +371,7 @@ func (m *DockerManager) follow(ctx context.Context, c DockerContainer) {
 			if ctx.Err() != nil {
 				return
 			}
-			log.Printf("docker %s: %v", c.Name, err)
+			logEvent("docker", 4, "container %s: cannot inspect it: %v", c.Name, err)
 			sleepCtx(ctx, 5*time.Second)
 			continue
 		}
@@ -383,22 +383,25 @@ func (m *DockerManager) follow(ctx context.Context, c DockerContainer) {
 			return
 		}
 		if err != nil && !errors.Is(err, io.EOF) && !errors.Is(err, io.ErrUnexpectedEOF) {
-			log.Printf("docker %s: %v", c.Name, err)
+			logEvent("docker", 4, "container %s: log stream lost, reconnecting: %v", c.Name, err)
 		}
 		sleepCtx(ctx, time.Second)
 	}
 }
 
-func sleepCtx(ctx context.Context, d time.Duration) {
+// sleepCtx waits for d, or returns false if the context ends first.
+func sleepCtx(ctx context.Context, d time.Duration) bool {
 	t := time.NewTimer(d)
 	defer t.Stop()
 	select {
 	case <-ctx.Done():
+		return false
 	case <-t.C:
+		return true
 	}
 }
 
-// since returns where to resume reading: just after the last line read, or
+// since returns where to resume reading: just after the last line stored, or
 // DOCKER_BACKFILL ago for a container seen for the first time.
 func (m *DockerManager) since(id string) time.Time {
 	m.mu.Lock()
@@ -530,8 +533,6 @@ func (m *DockerManager) emit(c DockerContainer, stream string, line []byte) {
 	} else if t, err := time.Parse(time.RFC3339Nano, s); err == nil {
 		ts, s = t, ""
 	}
-	defer m.setCheckpoint(c.ID, ts)
-
 	s = ansiRe.ReplaceAllString(s, "")
 	if !utf8.ValidString(s) {
 		s = strings.ToValidUTF8(s, string(utf8.RuneError))
@@ -575,6 +576,10 @@ func (m *DockerManager) emit(c DockerContainer, stream string, line []byte) {
 			"compose_service": c.Service,
 			"stream":          stream,
 		},
+		// Docker keeps the logs: wait for room in the queue rather than drop the
+		// line, and resume after it only once it is stored.
+		Wait: true,
+		Done: func() { m.setCheckpoint(c.ID, ts) },
 	})
 }
 

docs/presets.fr.md

@@ -0,0 +1,114 @@
+[English](presets.md) · **Français**
+
+# Préréglages de tags de couleur
+
+Dans **Paramètres › Motifs de recherche**, le menu **+ Préréglage…** ajoute d'un clic un groupe de tags de
+couleur tout faits. Les tags ajoutés sont des tags ordinaires : vous pouvez changer leur couleur,
+leur motif ou leurs options, ou les supprimer. Un tag dont le motif est déjà dans la liste n'est
+pas ajouté en double.
+
+La liste vient d'un fichier texte, [`presets.json`](../presets.json), intégré à LogStream. Vous
+pouvez le remplacer par votre propre fichier (voir [Utiliser votre propre fichier](#utiliser-votre-propre-fichier)).
+
+## Préréglages intégrés
+
+### HTTP/HTTPS
+
+Ces préréglages lisent les logs d'accès de nginx et Apache (formats common et combined), Traefik
+(CLF et JSON), Caddy (JSON) et HAProxy (`option httplog`).
+
+| Préréglage | Tags | Ce qui est coloré |
+| --- | --- | --- |
+| Codes HTTP | `HTTP 2xx` vert, `HTTP 3xx` bleu, `HTTP 4xx` orange, `HTTP 5xx` rouge | seulement le code de statut, par exemple `404` dans `"GET /x HTTP/1.1" 404 153`, `"status":404` ou `"DownstreamStatus":404`. Les autres nombres de la ligne (taille, chemin) ne sont pas touchés. |
+| Méthodes HTTP | `GET/HEAD/OPTIONS` gris, `POST/PUT/PATCH` violet, `DELETE` rose | seulement la méthode dans `"GET /chemin` ou `"method":"GET"` (en majuscules uniquement) |
+| Sondes et attaques | `sondes / attaques` | `wp-login.php`, `xmlrpc.php`, `wp-admin`, `phpmyadmin`, `/.env`, `/.git`, `/.aws`, `/cgi-bin/`, `../`, `%2e%2e`, `/etc/passwd`, `<script`, `union select` |
+| Robots et scripts | `robots / scripts` | les mots finissant par `bot` (`Googlebot`, `bingbot`…), `crawler`, `spider`, `curl`, `wget`, `python-requests`, `Go-http-client`, `zgrab`, `masscan`, `nmap`, `sqlmap`, `nikto` |
+| Erreurs TLS/HTTPS et proxy | `erreurs TLS`, `erreurs proxy` | échecs de handshake TLS, certificats expirés ou refusés, `x509:` ; `upstream timed out`, `no live upstreams`, `connect() failed`, `connection refused`, `bad gateway`, `gateway timeout`, `service unavailable` |
+
+### Système
+
+| Préréglage | Tags | Ce qui est coloré |
+| --- | --- | --- |
+| SSH et connexions | `échecs de connexion` rouge, `connexions` vert | sshd/PAM : `Failed password`, `Invalid user`, `authentication failure`, `incorrect password attempts`, `NOT in sudoers`… ; `Accepted publickey`, `session opened for user`, `New session … of user` |
+| Commandes sudo | `commandes sudo` | la commande lancée, par exemple `COMMAND=/usr/bin/apt` |
+| Noyau : OOM, plantages, disques | `mémoire épuisée`, `erreurs noyau` | `Out of memory`, `oom-killer`, `Killed process 4242` ; `Kernel panic`, `BUG:`, `Oops`, `Call Trace`, `segfault at`, `I/O error`, `EXT4-fs error`, `blocked for more than 120 seconds`, `soft lockup` |
+| Services systemd | `services en échec` rouge, `démarrage/arrêt de service` vert | `Failed to start`, `Failed with result`, `Main process exited, code=killed`, `Start request repeated too quickly` ; `Started`, `Stopping`, `Reloaded`, `Reached target` |
+| Pare-feu et fail2ban | `pare-feu` | `[UFW BLOCK]`, `[UFW ALLOW]`, `DROP`, `REJECT`, `Ban 203.0.113.9`, `Unban …`, `Found …` |
+
+### Applications
+
+| Préréglage | Tags | Ce qui est coloré |
+| --- | --- | --- |
+| Docker et conteneurs | `problèmes de conteneur` | `exited with code 137` (codes non nuls seulement), `OOMKilled`, `unhealthy`, `Back-off restarting`, `CrashLoopBackOff`, `container die/kill/oom` |
+| Bases de données | `erreurs base de données` | PostgreSQL et MySQL/MariaDB : `deadlock detected`, `duplicate key`, `too many connections`, `lock wait timeout`, `slow query`, `server has gone away`, `Access denied for user`, `password authentication failed`… |
+
+### Général
+
+| Préréglage | Tags | Ce qui est coloré |
+| --- | --- | --- |
+| Niveaux de log | `fatal / critique` rouge, `info / notice` bleu, `debug / trace` gris, `ok` vert | ces mots en mots entiers, quelle que soit la casse (les tags par défaut `warning` et `error` couvrent le reste) |
+| Adresses IPv4 | `adresses IPv4` | `192.168.1.20`, `203.0.113.9`… Les numéros de version à quatre parties comme `1.2.3.4` sont aussi colorés. |
+
+Quand des tags se chevauchent, celui placé le plus haut dans la liste l'emporte : les
+préréglages ajoutés après les tags par défaut ne les masquent donc jamais.
+
+## Utiliser votre propre fichier
+
+LogStream lit le fichier indiqué par `PRESETS_FILE`, `/data/presets.json` par défaut (dans le
+volume `logstream-data`). S'il n'existe pas, la liste intégrée est utilisée. Le fichier est relu
+à chaque ouverture des Paramètres : pas besoin de redémarrer après une modification.
+
+Avec docker-compose, le plus simple est de garder le fichier à côté de `docker-compose.yml` :
+
+1. Copiez [`presets.json`](../presets.json) depuis ce dépôt et modifiez-le.
+2. Dans `docker-compose.yml`, décommentez la ligne `- ./presets.json:/config/presets.json:ro`.
+3. Dans `.env`, mettez `PRESETS_FILE=/config/presets.json`, puis lancez `docker compose up -d`.
+
+Si le fichier est invalide (erreur JSON, expression régulière ou couleur incorrecte, id en
+double), les Paramètres affichent l'erreur et la liste intégrée est utilisée jusqu'à correction.
+
+## Format du fichier
+
+Le fichier est une liste JSON de groupes. Chaque groupe a un nom et une liste de préréglages ;
+chaque préréglage a un `id`, un nom et ses tags.
+
+```json
+[
+  {
+    "group": { "en": "My apps", "fr": "Mes applis" },
+    "presets": [
+      {
+        "id": "monappli",
+        "name": "Mon appli",
+        "tags": [
+          { "label": "paiement refusé", "color": "#fca5a5", "pattern": "payment (?:failed|refused)" },
+          { "label": "commande", "color": "#86efac", "pattern": "order #\\d+" },
+          { "label": "lent", "color": "#fde68a", "pattern": "SLOW", "regex": false, "caseSensitive": true }
+        ]
+      }
+    ]
+  }
+]
+```
+
+| Champ | Obligatoire | Signification |
+| --- | --- | --- |
+| `group` | oui | nom du groupe dans le menu |
+| `id` | oui | identifiant unique du préréglage |
+| `name` | oui | nom du préréglage dans le menu |
+| `tags[].pattern` | oui | ce qu'il faut colorer : une expression régulière, ou du texte simple avec `"regex": false` |
+| `tags[].color` | oui | couleur de fond, `#rrggbb` |
+| `tags[].label` | non | nom affiché dans la liste des tags à la place du motif |
+| `tags[].regex` | non | `true` par défaut |
+| `tags[].wholeWord` | non | mots entiers seulement, `false` par défaut |
+| `tags[].caseSensitive` | non | respecter la casse, `false` par défaut |
+
+Les noms et libellés sont soit un seul texte pour toutes les langues (`"Mon appli"`), soit un
+texte par langue (`{ "en": "My app", "fr": "Mon appli" }`) ; une langue absente se rabat sur
+l'anglais.
+
+Les expressions régulières doivent fonctionner à la fois dans le navigateur (JavaScript) et en
+Go, qui les vérifie : évitez les assertions arrière `(?<=…)`, avant `(?=…)` et les références
+arrière `\1`. En JSON, chaque barre oblique inverse s'écrit deux fois : `\d` devient `"\\d"`. Un
+groupe nommé `hl`, `(?<hl>…)`, ne colore que cette partie de la correspondance, comme le font
+les préréglages HTTP avec `(?<hl>5\\d\\d)`.

docs/presets.md

@@ -0,0 +1,111 @@
+**English** · [Français](presets.fr.md)
+
+# Color tag presets
+
+In **Settings › Patterns**, the **+ Preset…** menu adds a group of ready-made color tags in one
+click. Added tags are ordinary tags: you can change their color, pattern or options, or delete
+them. A tag whose pattern is already in the list is not added twice.
+
+The list comes from a text file, [`presets.json`](../presets.json), built into LogStream. You
+can replace it with your own file (see [Using your own file](#using-your-own-file)).
+
+## Built-in presets
+
+### HTTP/HTTPS
+
+These presets read access logs from nginx and Apache (common and combined formats), Traefik
+(CLF and JSON), Caddy (JSON) and HAProxy (`option httplog`).
+
+| Preset | Tags | What gets colored |
+| --- | --- | --- |
+| HTTP status codes | `HTTP 2xx` green, `HTTP 3xx` blue, `HTTP 4xx` orange, `HTTP 5xx` red | only the status code, e.g. `404` in `"GET /x HTTP/1.1" 404 153`, `"status":404` or `"DownstreamStatus":404`. Other numbers on the line (size, path) are left alone. |
+| HTTP methods | `GET/HEAD/OPTIONS` grey, `POST/PUT/PATCH` purple, `DELETE` pink | only the method in `"GET /path` or `"method":"GET"` (upper case only) |
+| Probes and attacks | `probes / attacks` | `wp-login.php`, `xmlrpc.php`, `wp-admin`, `phpmyadmin`, `/.env`, `/.git`, `/.aws`, `/cgi-bin/`, `../`, `%2e%2e`, `/etc/passwd`, `<script`, `union select` |
+| Bots and scripts | `bots / scripts` | words ending in `bot` (`Googlebot`, `bingbot`…), `crawler`, `spider`, `curl`, `wget`, `python-requests`, `Go-http-client`, `zgrab`, `masscan`, `nmap`, `sqlmap`, `nikto` |
+| TLS/HTTPS and proxy errors | `TLS errors`, `proxy errors` | TLS handshake failures, expired or rejected certificates, `x509:`; `upstream timed out`, `no live upstreams`, `connect() failed`, `connection refused`, `bad gateway`, `gateway timeout`, `service unavailable` |
+
+### System
+
+| Preset | Tags | What gets colored |
+| --- | --- | --- |
+| SSH and logins | `login failures` red, `logins` green | sshd/PAM: `Failed password`, `Invalid user`, `authentication failure`, `incorrect password attempts`, `NOT in sudoers`…; `Accepted publickey`, `session opened for user`, `New session … of user` |
+| sudo commands | `sudo commands` | the command run, e.g. `COMMAND=/usr/bin/apt` |
+| Kernel: OOM, crashes, disks | `out of memory`, `kernel errors` | `Out of memory`, `oom-killer`, `Killed process 4242`; `Kernel panic`, `BUG:`, `Oops`, `Call Trace`, `segfault at`, `I/O error`, `EXT4-fs error`, `blocked for more than 120 seconds`, `soft lockup` |
+| systemd services | `failed services` red, `service start/stop` green | `Failed to start`, `Failed with result`, `Main process exited, code=killed`, `Start request repeated too quickly`; `Started`, `Stopping`, `Reloaded`, `Reached target` |
+| Firewall and fail2ban | `firewall` | `[UFW BLOCK]`, `[UFW ALLOW]`, `DROP`, `REJECT`, `Ban 203.0.113.9`, `Unban …`, `Found …` |
+
+### Applications
+
+| Preset | Tags | What gets colored |
+| --- | --- | --- |
+| Docker and containers | `container problems` | `exited with code 137` (non-zero codes only), `OOMKilled`, `unhealthy`, `Back-off restarting`, `CrashLoopBackOff`, `container die/kill/oom` |
+| Databases | `database errors` | PostgreSQL and MySQL/MariaDB: `deadlock detected`, `duplicate key`, `too many connections`, `lock wait timeout`, `slow query`, `server has gone away`, `Access denied for user`, `password authentication failed`… |
+
+### General
+
+| Preset | Tags | What gets colored |
+| --- | --- | --- |
+| Log levels | `fatal / critical` red, `info / notice` blue, `debug / trace` grey, `ok` green | these words as whole words, any case (the default `warning` and `error` tags cover the rest) |
+| IPv4 addresses | `IPv4 addresses` | `192.168.1.20`, `203.0.113.9`… Four-part version numbers such as `1.2.3.4` are colored too. |
+
+When tags overlap, the one highest in the tag list wins, so presets added after the default
+tags never hide them.
+
+## Using your own file
+
+LogStream reads the file named by `PRESETS_FILE`, `/data/presets.json` by default (in the
+`logstream-data` volume). When the file does not exist, the built-in list is used. The file is
+read again each time Settings is opened: no restart is needed after an edit.
+
+With docker-compose, the simplest is to keep the file next to `docker-compose.yml`:
+
+1. Copy [`presets.json`](../presets.json) from this repository and edit it.
+2. In `docker-compose.yml`, uncomment the line `- ./presets.json:/config/presets.json:ro`.
+3. In `.env`, set `PRESETS_FILE=/config/presets.json`, then run `docker compose up -d`.
+
+If the file is invalid (JSON error, bad regular expression or color, duplicate id), Settings
+shows the error and the built-in list is used until the file is fixed.
+
+## File format
+
+The file is a JSON list of groups. Each group has a name and a list of presets; each preset has
+an `id`, a name and its tags.
+
+```json
+[
+  {
+    "group": { "en": "My apps", "fr": "Mes applis" },
+    "presets": [
+      {
+        "id": "myapp",
+        "name": "My app",
+        "tags": [
+          { "label": "payment failed", "color": "#fca5a5", "pattern": "payment (?:failed|refused)" },
+          { "label": "order", "color": "#86efac", "pattern": "order #\\d+" },
+          { "label": "slow", "color": "#fde68a", "pattern": "SLOW", "regex": false, "caseSensitive": true }
+        ]
+      }
+    ]
+  }
+]
+```
+
+| Field | Required | Meaning |
+| --- | --- | --- |
+| `group` | yes | name of the group in the menu |
+| `id` | yes | unique identifier of the preset |
+| `name` | yes | name of the preset in the menu |
+| `tags[].pattern` | yes | what to color: a regular expression, or plain text with `"regex": false` |
+| `tags[].color` | yes | background color, `#rrggbb` |
+| `tags[].label` | no | name shown in the tag list instead of the pattern |
+| `tags[].regex` | no | `true` by default |
+| `tags[].wholeWord` | no | only match whole words, `false` by default |
+| `tags[].caseSensitive` | no | match case, `false` by default |
+
+Names and labels are either one text for every language (`"My app"`) or one text per language
+(`{ "en": "My app", "fr": "Mon appli" }`); a missing language falls back to English.
+
+Regular expressions must work both in the browser (JavaScript) and in Go, which checks them:
+avoid look-behind `(?<=…)`, look-ahead `(?=…)` and back-references `\1`. In JSON, every
+backslash is written twice: `\d` becomes `"\\d"`. A group named `hl`, `(?<hl>…)`, colors only
+that part of the match, as the HTTP presets do with `(?<hl>5\\d\\d)`.

fileformats.go

@@ -0,0 +1,689 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"os"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+	"unicode/utf8"
+)
+
+// Formats of the "Files" source (Settings > Sources), one per declared file.
+const (
+	fmtAuto    = "auto"    // detected from the last lines of the file
+	fmtText    = "text"    // one line per entry, level and leading timestamp detected
+	fmtJSON    = "json"    // JSON lines: msg/time/level recognized, other keys as fields
+	fmtLogfmt  = "logfmt"  // key=value pairs (Traefik "common" logs, Go programs…)
+	fmtRegex   = "regex"   // regular expression with named groups
+	fmtCLF     = "clf"     // access logs in Common/Combined Log Format (nginx, Apache, Traefik)
+	fmtTraefik = "traefik" // Traefik access log in JSON
+)
+
+var fileFormats = map[string]bool{fmtText: true, fmtJSON: true, fmtLogfmt: true, fmtRegex: true, fmtCLF: true, fmtTraefik: true}
+
+// fileRec is one parsed line (or several, for continuation lines).
+type fileRec struct {
+	t      time.Time
+	dated  bool // t comes from the line
+	sev    int
+	msg    string
+	host   string
+	app    string
+	fields map[string]string
+}
+
+const (
+	maxFileFields   = 64
+	maxFieldValue   = 4096
+	maxFileMsg      = 64 << 10 // message with its continuation lines
+	maxContinuation = 500      // continuation lines added to one entry
+)
+
+// fileParser turns a line of a file into an entry, for one format.
+type fileParser struct {
+	format string
+	re     *regexp.Regexp // fmtRegex
+}
+
+func newFileParser(format, expr string) (*fileParser, error) {
+	if !fileFormats[format] {
+		return nil, fmt.Errorf("unknown format %q", format)
+	}
+	p := &fileParser{format: format}
+	if format == fmtRegex {
+		if strings.TrimSpace(expr) == "" {
+			return nil, fmt.Errorf("the regex format needs a regular expression")
+		}
+		re, err := regexp.Compile(expr)
+		if err != nil {
+			return nil, fmt.Errorf("invalid regular expression: %v", err)
+		}
+		p.re = re
+	}
+	return p, nil
+}
+
+// multiline tells whether lines that do not start an entry are added to the
+// previous one (stack traces…). Structured formats are one entry per line.
+func (p *fileParser) multiline() bool {
+	return p.format == fmtText || p.format == fmtRegex
+}
+
+// continuation reports a line that belongs to the previous entry: indented,
+// or not matching the regular expression.
+func (p *fileParser) continuation(line string) bool {
+	if line != "" && (line[0] == ' ' || line[0] == '\t') {
+		return true
+	}
+	return p.format == fmtRegex && !p.re.MatchString(line)
+}
+
+// parse decodes one line; it never fails (a line in another format is kept as text).
+func (p *fileParser) parse(line string, now time.Time) *fileRec {
+	line = cleanLine(line)
+	switch p.format {
+	case fmtJSON, fmtTraefik:
+		if obj, ok := decodeJSONLine(line); ok {
+			if p.format == fmtTraefik {
+				if r := traefikRec(obj, line, now); r != nil {
+					return r
+				}
+			}
+			return jsonRec(obj, line, now)
+		}
+	case fmtLogfmt:
+		if kv := parseLogfmt(line); len(kv) > 0 {
+			return logfmtRec(kv, line, now)
+		}
+	case fmtRegex:
+		if m := p.re.FindStringSubmatch(line); m != nil {
+			return p.regexRec(m, line, now)
+		}
+	case fmtCLF:
+		if r := clfRec(line, now); r != nil {
+			return r
+		}
+	}
+	return textRec(line, now)
+}
+
+func cleanLine(s string) string {
+	s = strings.TrimRight(s, "\r")
+	s = ansiRe.ReplaceAllString(s, "")
+	if !utf8.ValidString(s) {
+		s = strings.ToValidUTF8(s, "�")
+	}
+	return s
+}
+
+// textRec: the line itself, without its leading timestamp when there is one.
+func textRec(line string, now time.Time) *fileRec {
+	r := &fileRec{t: now, sev: 6, msg: line}
+	if m := leadTimeRe.FindStringSubmatchIndex(line); m != nil {
+		if t, ok := parseLogTime(line[m[2]:m[3]], now); ok {
+			r.t, r.dated = t, true
+			if rest := line[m[1]:]; strings.TrimSpace(rest) != "" {
+				r.msg = rest
+			}
+		}
+	}
+	if n, ok := detectLevel(r.msg); ok {
+		r.sev = n
+	}
+	return r
+}
+
+/* ---------- Timestamps ---------- */
+
+// leadTimeRe: a timestamp at the start of a line, possibly in brackets
+// (ISO 8601 / RFC 3339, 2006/01/02 15:04:05, CLF, syslog "Jan _2 15:04:05").
+var leadTimeRe = regexp.MustCompile(`^\[?(\d{4}[-/]\d{2}[-/]\d{2}[T ]\d{2}:\d{2}:\d{2}(?:[.,]\d+)?(?: ?(?:Z|[+-]\d{2}:?\d{2}))?|\d{2}/[A-Z][a-z]{2}/\d{4}:\d{2}:\d{2}:\d{2} [+-]\d{4}|[A-Z][a-z]{2} +\d{1,2} \d{2}:\d{2}:\d{2})\]?[ \t]*(?:[-|:][ \t]+)?`)
+
+var timeLayouts = []string{
+	time.RFC3339Nano,
+	"2006-01-02T15:04:05Z0700",
+	"2006-01-02T15:04:05",
+	"02/Jan/2006:15:04:05 -0700",
+	"Jan _2 15:04:05",
+	time.RFC1123Z,
+	time.RFC1123,
+	time.UnixDate,
+	time.ANSIC,
+}
+
+// parseLogTime reads the usual log timestamps; times without a zone are local.
+func parseLogTime(s string, now time.Time) (time.Time, bool) {
+	s = strings.TrimSpace(s)
+	if s == "" {
+		return time.Time{}, false
+	}
+	if s[0] >= '0' && s[0] <= '9' && !strings.ContainsAny(s, ":/-") {
+		if whole, _, _ := strings.Cut(s, "."); len(whole) < 9 {
+			return time.Time{}, false // not a Unix time of this century
+		}
+		return epochTime(s)
+	}
+	// 2006/01/02 15:04:05,123 +02:00 -> 2006-01-02T15:04:05.123+02:00
+	if len(s) >= 19 && s[4] == '/' && s[7] == '/' {
+		s = s[:4] + "-" + s[5:7] + "-" + s[8:]
+	}
+	if len(s) >= 19 && s[4] == '-' && s[10] == ' ' {
+		s = s[:10] + "T" + s[11:]
+	}
+	if len(s) > 19 && s[4] == '-' {
+		s = s[:19] + strings.Replace(strings.Replace(s[19:], ",", ".", 1), " ", "", 1)
+	}
+	s = strings.Join(strings.Fields(s), " ") // "Jan  5" -> "Jan 5"
+	for _, layout := range timeLayouts {
+		if layout == "Jan _2 15:04:05" {
+			layout = "Jan 2 15:04:05"
+		}
+		t, err := time.ParseInLocation(layout, s, time.Local)
+		if err != nil {
+			continue
+		}
+		if t.Year() == 0 { // syslog timestamps have no year
+			t = t.AddDate(now.Year(), 0, 0)
+			if t.After(now.Add(24 * time.Hour)) {
+				t = t.AddDate(-1, 0, 0)
+			}
+		}
+		return t, true
+	}
+	return time.Time{}, false
+}
+
+// epochTime reads a Unix time in seconds, milliseconds, microseconds or
+// nanoseconds (guessed from its size), with an optional fraction.
+func epochTime(s string) (time.Time, bool) {
+	f, err := strconv.ParseFloat(s, 64)
+	if err != nil || f <= 0 {
+		return time.Time{}, false
+	}
+	switch {
+	case f < 1e11:
+		return time.Unix(0, int64(f*1e9)), true
+	case f < 1e14:
+		return time.UnixMilli(int64(f)), true
+	case f < 1e17:
+		return time.UnixMicro(int64(f)), true
+	}
+	return time.Unix(0, int64(f)), true
+}
+
+/* ---------- Fields ---------- */
+
+// reservedFields are stored by LogStream itself: fields of the logs with the
+// same name are renamed field_<name>.
+var reservedFields = map[string]bool{
+	"_time": true, "_msg": true, "_stream": true, "_stream_id": true, "received": true, "msg_time": true,
+	"host": true, "host_name": true, "host_ip": true, "app": true, "facility": true, "severity": true,
+	"sevnum": true, "source": true, "proto": true, "procid": true, "sd": true, "source_type": true, "log_file": true,
+}
+
+func fieldName(k string) string {
+	k = strings.Map(func(r rune) rune {
+		if r == '_' || r == '.' || r == '-' || r >= '0' && r <= '9' || r >= 'a' && r <= 'z' || r >= 'A' && r <= 'Z' {
+			return r
+		}
+		return '_'
+	}, k)
+	if k == "" || reservedFields[k] || k[0] == '_' {
+		k = "field_" + strings.TrimLeft(k, "_")
+	}
+	return k
+}
+
+func (r *fileRec) set(k, v string) {
+	if v == "" {
+		return
+	}
+	if r.fields == nil {
+		r.fields = map[string]string{}
+	}
+	k = fieldName(k)
+	if _, ok := r.fields[k]; !ok && len(r.fields) >= maxFileFields {
+		return
+	}
+	if len(v) > maxFieldValue {
+		v = strings.ToValidUTF8(v[:maxFieldValue], "") + "…"
+	}
+	r.fields[k] = v
+}
+
+/* ---------- JSON lines ---------- */
+
+func decodeJSONLine(line string) (map[string]any, bool) {
+	s := strings.TrimSpace(line)
+	if len(s) < 2 || s[0] != '{' {
+		return nil, false
+	}
+	dec := json.NewDecoder(strings.NewReader(s))
+	dec.UseNumber()
+	var obj map[string]any
+	if dec.Decode(&obj) != nil {
+		return nil, false
+	}
+	return obj, true
+}
+
+var (
+	jsonMsgKeys   = []string{"msg", "message", "@message", "log", "text"}
+	jsonTimeKeys  = []string{"time", "ts", "timestamp", "@timestamp", "@t", "t", "datetime", "date"}
+	jsonLevelKeys = []string{"level", "lvl", "severity", "log.level", "@level", "@l", "loglevel", "levelname"}
+)
+
+// takeString removes the first of keys found in obj and returns it as text.
+func takeString(obj map[string]any, keys []string) (string, bool) {
+	for _, k := range keys {
+		if v, ok := obj[k]; ok {
+			if s := scalarString(v); s != "" {
+				delete(obj, k)
+				return s, true
+			}
+		}
+	}
+	return "", false
+}
+
+func scalarString(v any) string {
+	switch v := v.(type) {
+	case string:
+		return v
+	case json.Number:
+		return v.String()
+	case bool:
+		return strconv.FormatBool(v)
+	}
+	return ""
+}
+
+func jsonRec(obj map[string]any, line string, now time.Time) *fileRec {
+	r := &fileRec{t: now, sev: 6, msg: line}
+	for _, k := range jsonTimeKeys {
+		if t, ok := parseLogTime(scalarString(obj[k]), now); ok {
+			r.t, r.dated = t, true
+			delete(obj, k)
+			break
+		}
+	}
+	lvl, hasLevel := takeString(obj, jsonLevelKeys)
+	if hasLevel {
+		if n, ok := levelNum(lvl); ok {
+			r.sev = n
+		} else if n, err := strconv.Atoi(lvl); err == nil {
+			r.sev = numericLevel(n)
+		} else {
+			r.set("level", lvl)
+		}
+	}
+	if s, ok := takeString(obj, jsonMsgKeys); ok {
+		r.msg = strings.TrimRight(s, "\n")
+	}
+	flattenJSON("", obj, r)
+	if !hasLevel {
+		if n, ok := detectLevel(r.msg); ok {
+			r.sev = n
+		}
+	}
+	return r
+}
+
+// numericLevel maps numeric levels: syslog (0-7) or pino/bunyan (10-60).
+func numericLevel(n int) int {
+	switch {
+	case n >= 0 && n <= 7:
+		return n
+	case n >= 60:
+		return 2
+	case n >= 50:
+		return 3
+	case n >= 40:
+		return 4
+	case n >= 30:
+		return 6
+	}
+	return 7
+}
+
+// flattenJSON stores the remaining keys as fields; nested objects give
+// dotted names, arrays stay in JSON.
+func flattenJSON(prefix string, obj map[string]any, r *fileRec) {
+	for k, v := range obj {
+		name := prefix + k
+		switch v := v.(type) {
+		case map[string]any:
+			flattenJSON(name+".", v, r)
+		case []any:
+			b, _ := json.Marshal(v)
+			r.set(name, string(b))
+		case nil:
+		default:
+			r.set(name, scalarString(v))
+		}
+	}
+}
+
+/* ---------- logfmt ---------- */
+
+// parseLogfmt splits `k=v k2="v 2"` (with \" escapes); words without a value
+// are skipped. Nil when the line has no pair.
+func parseLogfmt(s string) [][2]string {
+	var out [][2]string
+	for i := 0; i < len(s); {
+		for i < len(s) && (s[i] == ' ' || s[i] == '\t') {
+			i++
+		}
+		start := i
+		for i < len(s) && s[i] != '=' && s[i] != ' ' && s[i] != '\t' {
+			i++
+		}
+		if i >= len(s) || s[i] != '=' || i == start {
+			for i < len(s) && s[i] != ' ' && s[i] != '\t' {
+				i++
+			}
+			continue
+		}
+		k := s[start:i]
+		i++
+		var v string
+		if i < len(s) && s[i] == '"' {
+			var b strings.Builder
+			i++
+			for i < len(s) && s[i] != '"' {
+				if s[i] == '\\' && i+1 < len(s) {
+					i++
+					switch s[i] {
+					case 'n':
+						b.WriteByte('\n')
+					case 't':
+						b.WriteByte('\t')
+					default:
+						b.WriteByte(s[i])
+					}
+				} else {
+					b.WriteByte(s[i])
+				}
+				i++
+			}
+			i++ // closing quote
+			v = b.String()
+		} else {
+			end := i
+			for end < len(s) && s[end] != ' ' && s[end] != '\t' {
+				end++
+			}
+			v, i = s[i:end], end
+		}
+		out = append(out, [2]string{k, v})
+	}
+	return out
+}
+
+func logfmtRec(kv [][2]string, line string, now time.Time) *fileRec {
+	obj := make(map[string]any, len(kv))
+	for _, p := range kv {
+		obj[p[0]] = p[1]
+	}
+	return jsonRec(obj, line, now)
+}
+
+/* ---------- Regular expression ---------- */
+
+func (p *fileParser) regexRec(m []string, line string, now time.Time) *fileRec {
+	r := &fileRec{t: now, sev: 6, msg: line}
+	hasLevel := false
+	for i, name := range p.re.SubexpNames() {
+		if i == 0 || name == "" || m[i] == "" {
+			continue
+		}
+		v := m[i]
+		switch strings.ToLower(name) {
+		case "time", "timestamp", "ts":
+			if t, ok := parseLogTime(v, now); ok {
+				r.t, r.dated = t, true
+			}
+		case "level", "severity", "lvl":
+			if n, ok := levelNum(v); ok {
+				r.sev, hasLevel = n, true
+			}
+		case "msg", "message":
+			r.msg = v
+		case "host":
+			r.host = v
+		case "app":
+			r.app = v
+		case "status":
+			r.set(name, v)
+			if n, ok := statusLevel(v); ok && !hasLevel {
+				r.sev, hasLevel = n, true
+			}
+		default:
+			r.set(name, v)
+		}
+	}
+	if !hasLevel {
+		if n, ok := detectLevel(r.msg); ok {
+			r.sev = n
+		}
+	}
+	return r
+}
+
+/* ---------- Access logs ---------- */
+
+// statusLevel: 5xx are errors, 4xx warnings, the rest info.
+func statusLevel(s string) (int, bool) {
+	n, err := strconv.Atoi(s)
+	if err != nil || n < 100 || n > 999 {
+		return 0, false
+	}
+	switch {
+	case n >= 500:
+		return 3, true
+	case n >= 400:
+		return 4, true
+	}
+	return 6, true
+}
+
+// clfRe: Common Log Format, the combined extension (referer, user agent) and
+// the Traefik one (request count, router, server URL, duration).
+var clfRe = regexp.MustCompile(`^(\S+) (\S+) (\S+) \[([^\]]+)\] "((?:[^"\\]|\\.)*)" (\d{3}) (\d+|-)(?: "((?:[^"\\]|\\.)*)" "((?:[^"\\]|\\.)*)")?(?: (\d+) "([^"]*)" "([^"]*)" (\d+)ms)?`)
+
+func clfRec(line string, now time.Time) *fileRec {
+	m := clfRe.FindStringSubmatch(line)
+	if m == nil {
+		return nil
+	}
+	r := &fileRec{t: now, sev: 6, msg: line}
+	if t, ok := parseLogTime(m[4], now); ok {
+		r.t, r.dated = t, true
+	}
+	dash := func(s string) string {
+		if s == "-" {
+			return ""
+		}
+		return s
+	}
+	r.set("client_ip", m[1])
+	r.set("http_user", dash(m[3]))
+	if req := strings.Fields(m[5]); len(req) == 3 {
+		r.set("http_method", req[0])
+		r.set("http_path", req[1])
+		r.set("http_proto", req[2])
+	} else {
+		r.set("http_request", m[5])
+	}
+	r.set("http_status", m[6])
+	r.set("http_size", dash(m[7]))
+	r.set("http_referer", dash(m[8]))
+	r.set("user_agent", dash(m[9]))
+	r.set("router", dash(m[11]))
+	r.set("backend", dash(m[12]))
+	r.set("duration_ms", m[13])
+	r.sev, _ = statusLevel(m[6])
+	return r
+}
+
+// traefikRec reads a Traefik access log line in JSON; nil for the other
+// lines (Traefik's own logs), read as generic JSON.
+func traefikRec(obj map[string]any, line string, now time.Time) *fileRec {
+	status := scalarString(obj["DownstreamStatus"])
+	if status == "" {
+		status = scalarString(obj["OriginStatus"])
+	}
+	method := scalarString(obj["RequestMethod"])
+	if status == "" && method == "" {
+		return nil
+	}
+	r := &fileRec{t: now, sev: 6}
+	if t, ok := parseLogTime(firstNonEmpty(scalarString(obj["StartUTC"]), scalarString(obj["time"])), now); ok {
+		r.t, r.dated = t, true
+	}
+	if n, ok := statusLevel(status); ok {
+		r.sev = n
+	}
+	rename := map[string]string{
+		"ClientHost": "client_ip", "ClientUsername": "http_user", "RequestMethod": "http_method",
+		"RequestHost": "http_host", "RequestPath": "http_path", "RequestProtocol": "http_proto",
+		"DownstreamStatus": "http_status", "DownstreamContentSize": "http_size", "OriginStatus": "origin_status",
+		"RouterName": "router", "ServiceName": "service", "ServiceURL": "backend", "entryPointName": "entrypoint",
+		"request_User-Agent": "user_agent", "request_Referer": "http_referer",
+	}
+	dur := ""
+	if d, err := strconv.ParseFloat(scalarString(obj["Duration"]), 64); err == nil {
+		dur = strconv.FormatFloat(d/1e6, 'f', -1, 64)
+		r.set("duration_ms", dur)
+	}
+	for _, k := range []string{"Duration", "StartUTC", "StartLocal", "time", "level", "msg"} {
+		delete(obj, k)
+	}
+	for k, v := range obj {
+		if to, ok := rename[k]; ok {
+			r.set(to, scalarString(v))
+			delete(obj, k)
+		}
+	}
+	flattenJSON("", obj, r)
+	// "GET example.com/path 404 · 12.5 ms · router@docker"
+	var b strings.Builder
+	b.WriteString(firstNonEmpty(method, "-"))
+	b.WriteByte(' ')
+	b.WriteString(r.fields["http_host"])
+	b.WriteString(r.fields["http_path"])
+	b.WriteByte(' ')
+	b.WriteString(firstNonEmpty(status, "-"))
+	if dur != "" {
+		b.WriteString(" · " + dur + " ms")
+	}
+	if rt := r.fields["router"]; rt != "" {
+		b.WriteString(" · " + rt)
+	}
+	if ip := r.fields["client_ip"]; ip != "" {
+		b.WriteString(" · " + ip)
+	}
+	r.msg = b.String()
+	return r
+}
+
+/* ---------- Detection ---------- */
+
+const detectWindow = 64 << 10
+
+// sampleLines returns the last complete lines of a file (50 at most).
+func sampleLines(path string) ([]string, error) {
+	fh, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer fh.Close()
+	fi, err := fh.Stat()
+	if err != nil {
+		return nil, err
+	}
+	off := fi.Size() - detectWindow
+	if off < 0 {
+		off = 0
+	}
+	buf, err := io.ReadAll(io.NewSectionReader(fh, off, detectWindow))
+	if err != nil {
+		return nil, err
+	}
+	end := bytes.LastIndexByte(buf, '\n')
+	if end < 0 {
+		return nil, nil
+	}
+	buf = buf[:end]
+	if off > 0 { // first line cut by the window
+		if nl := bytes.IndexByte(buf, '\n'); nl >= 0 {
+			buf = buf[nl+1:]
+		} else {
+			return nil, nil
+		}
+	}
+	var lines []string
+	for _, b := range bytes.Split(buf, []byte{'\n'}) {
+		if len(bytes.TrimSpace(b)) > 0 {
+			lines = append(lines, string(bytes.TrimRight(b, "\r")))
+		}
+	}
+	if len(lines) > 50 {
+		lines = lines[len(lines)-50:]
+	}
+	return lines, nil
+}
+
+// logfmtKeys: the pairs have one of the usual logfmt keys.
+func logfmtKeys(kv [][2]string) bool {
+	for _, p := range kv {
+		switch strings.ToLower(p[0]) {
+		case "level", "lvl", "msg", "message", "time", "ts", "t":
+			return true
+		}
+	}
+	return false
+}
+
+// detectFormat guesses the format of a file from some of its lines: the
+// structured format most lines follow, else plain text (a regular
+// expression is never guessed).
+func detectFormat(lines []string) string {
+	var js, traefik, clf, logfmt int
+	for _, l := range lines {
+		l = strings.TrimSpace(l)
+		if obj, ok := decodeJSONLine(l); ok {
+			js++
+			if _, ok := obj["RequestMethod"]; ok {
+				traefik++
+			} else if _, ok := obj["DownstreamStatus"]; ok {
+				traefik++
+			}
+			continue
+		}
+		if clfRe.MatchString(l) {
+			clf++
+			continue
+		}
+		if kv := parseLogfmt(l); len(kv) >= 3 && logfmtKeys(kv) {
+			logfmt++
+		}
+	}
+	most := func(n int) bool { return n > 0 && n*5 >= len(lines)*4 } // 80 %
+	switch {
+	case most(js) && traefik*2 >= js:
+		return fmtTraefik
+	case most(js):
+		return fmtJSON
+	case most(clf):
+		return fmtCLF
+	case most(logfmt):
+		return fmtLogfmt
+	}
+	return fmtText
+}

filesource.go

@@ -0,0 +1,711 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"crypto/rand"
+	"encoding/hex"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"sync"
+	"time"
+)
+
+// fileSourceDef is one log file declared in Settings > Sources.
+type fileSourceDef struct {
+	ID      string `json:"id"`
+	Name    string `json:"name"`            // app of the entries
+	Path    string `json:"path"`            // the file, as mounted in the container
+	Format  string `json:"format"`          // auto (detected), or text, json, logfmt, regex, clf, traefik
+	Regex   string `json:"regex,omitempty"` // format regex: named groups time, level, msg, host, app…
+	Host    string `json:"host,omitempty"`  // host of the entries (empty: the host name of the machine)
+	Enabled bool   `json:"enabled"`
+}
+
+// filesConfig is saved in /data/files.json.
+type filesConfig struct {
+	Sources []fileSourceDef `json:"sources"`
+}
+
+// filePos is where reading resumes in a file: its inode and an offset before
+// which every entry was sent. Until: end of the history found when the
+// source was turned on; entries before it are kept only when dated within
+// FILES_BACKFILL.
+type filePos struct {
+	Ino   uint64 `json:"ino"`
+	Off   int64  `json:"off"`
+	Until int64  `json:"until,omitempty"`
+}
+
+type filesState struct {
+	Pos     map[string]filePos   `json:"pos"`     // by source id
+	Started map[string]time.Time `json:"started"` // when each source was turned on
+}
+
+type fileSourceStatus struct {
+	Open     bool
+	Read     uint64
+	Detected string // format found when the source is in auto
+	Behind   int64  // bytes left to read (history being read)
+	Code     string
+	Error    string
+}
+
+// fileSource is a definition with its parser (nil in auto: detected from
+// the file).
+type fileSource struct {
+	fileSourceDef
+	parser *fileParser
+}
+
+// pendingEntry is an entry waiting for its continuation lines.
+type pendingEntry struct {
+	rec     *fileRec
+	off     int64     // offset of its first line
+	seen    time.Time // when its last line was read
+	history bool      // read from the history found when the source was turned on
+	lines   int
+}
+
+// fileTail is the reading state of one file, owned by the Run goroutine.
+type fileTail struct {
+	readOff int64 // where the next read starts (after the lines of the pending entry)
+	known   bool  // readOff is set
+	pending *pendingEntry
+	auto    *fileParser // format detected from the file, in auto
+	behind  int64       // bytes left to read after the last poll
+}
+
+// Files follows log files of other programs (Traefik, nginx, applications…)
+// mounted in the container, one entry per line in the format detected or
+// chosen for each file. Source type "file".
+type Files struct {
+	sink      func(*Entry)
+	hostName  string
+	backfill  time.Duration
+	cfgPath   string
+	statePath string
+	wake      chan struct{}
+
+	// Owned by the Run goroutine.
+	st    filesState
+	tails map[string]*fileTail
+	dirty bool
+
+	mu       sync.Mutex
+	cfg      []*fileSource
+	resets   map[string]bool // sources to read again from FILES_BACKFILL ago
+	redetect map[string]bool // sources whose format changed
+	status   map[string]*fileSourceStatus
+}
+
+func NewFiles(hostRoot, dataDir string, backfill time.Duration, sink func(*Entry)) *Files {
+	f := &Files{
+		sink:      sink,
+		hostName:  readTrim(filepath.Join(hostRoot, "etc/hostname")),
+		backfill:  backfill,
+		cfgPath:   filepath.Join(dataDir, "files.json"),
+		statePath: filepath.Join(dataDir, "files-state.json"),
+		wake:      make(chan struct{}, 1),
+		tails:     map[string]*fileTail{},
+		resets:    map[string]bool{},
+		redetect:  map[string]bool{},
+		status:    map[string]*fileSourceStatus{},
+	}
+	if f.hostName == "" {
+		f.hostName = "localhost"
+	}
+	var cfg filesConfig
+	if b, err := os.ReadFile(f.cfgPath); err == nil {
+		_ = json.Unmarshal(b, &cfg)
+	}
+	for _, d := range cfg.Sources {
+		src, err := compileFileSource(d)
+		if err != nil {
+			logEvent("files", 4, "file %q ignored: %v", d.Name, err)
+			continue
+		}
+		f.cfg = append(f.cfg, src)
+	}
+	if b, err := os.ReadFile(f.statePath); err == nil {
+		_ = json.Unmarshal(b, &f.st)
+	}
+	if f.st.Pos == nil {
+		f.st.Pos = map[string]filePos{}
+	}
+	if f.st.Started == nil {
+		f.st.Started = map[string]time.Time{}
+	}
+	return f
+}
+
+const maxFileSources = 50
+
+var fileIDRe = regexp.MustCompile(`^[0-9a-f]{1,32}$`)
+
+// checkFilePath: one file, absolute, without wildcards.
+func checkFilePath(p string) (string, error) {
+	p = strings.TrimSpace(p)
+	switch {
+	case !filepath.IsAbs(p):
+		return "", errors.New("the path must be absolute (as mounted in the container)")
+	case strings.ContainsAny(p, "*?["):
+		return "", errors.New("give the path of one file (no wildcards)")
+	}
+	return filepath.Clean(p), nil
+}
+
+// compileFileSource checks a definition and builds its parser.
+func compileFileSource(d fileSourceDef) (*fileSource, error) {
+	d.Name = strings.TrimSpace(d.Name)
+	d.Host = strings.TrimSpace(d.Host)
+	if d.Format == "" {
+		d.Format = fmtAuto
+	}
+	if d.Format != fmtRegex {
+		d.Regex = ""
+	}
+	switch {
+	case !fileIDRe.MatchString(d.ID):
+		return nil, errors.New("invalid id")
+	case d.Name == "" || len(d.Name) > 64:
+		return nil, errors.New("the name is required (64 characters at most)")
+	case len(d.Host) > 253:
+		return nil, fmt.Errorf("%s: host name too long", d.Name)
+	}
+	p, err := checkFilePath(d.Path)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %v", d.Name, err)
+	}
+	d.Path = p
+	src := &fileSource{fileSourceDef: d}
+	if d.Format != fmtAuto {
+		if src.parser, err = newFileParser(d.Format, d.Regex); err != nil {
+			return nil, fmt.Errorf("%s: %v", d.Name, err)
+		}
+	}
+	return src, nil
+}
+
+func newFileID() string {
+	b := make([]byte, 6)
+	_, _ = rand.Read(b)
+	return hex.EncodeToString(b)
+}
+
+// Configure checks, saves and applies the list of files. Files turned off,
+// removed or given another path are read again from FILES_BACKFILL ago the
+// next time they are on.
+func (f *Files) Configure(cfg filesConfig) error {
+	if len(cfg.Sources) > maxFileSources {
+		return fmt.Errorf("%d files at most", maxFileSources)
+	}
+	var srcs []*fileSource
+	ids := map[string]bool{}
+	for _, d := range cfg.Sources {
+		if d.ID == "" {
+			d.ID = newFileID()
+		}
+		if ids[d.ID] {
+			return fmt.Errorf("duplicate id %s", d.ID)
+		}
+		ids[d.ID] = true
+		src, err := compileFileSource(d)
+		if err != nil {
+			return err
+		}
+		srcs = append(srcs, src)
+	}
+	saved := filesConfig{Sources: []fileSourceDef{}}
+	for _, s := range srcs {
+		saved.Sources = append(saved.Sources, s.fileSourceDef)
+	}
+	if err := writeJSONFile(f.cfgPath, saved); err != nil {
+		return err
+	}
+	f.mu.Lock()
+	old := map[string]*fileSource{}
+	for _, s := range f.cfg {
+		old[s.ID] = s
+	}
+	for _, s := range srcs {
+		o := old[s.ID]
+		if o != nil && ((o.Enabled && !s.Enabled) || o.Path != s.Path) {
+			f.resets[s.ID] = true
+			delete(f.status, s.ID)
+		}
+		if o != nil && (o.Format != s.Format || o.Regex != s.Regex) {
+			f.redetect[s.ID] = true
+		}
+		delete(old, s.ID)
+	}
+	for id := range old { // removed
+		f.resets[id] = true
+		delete(f.status, id)
+	}
+	f.cfg = srcs
+	f.mu.Unlock()
+	select {
+	case f.wake <- struct{}{}:
+	default:
+	}
+	return nil
+}
+
+// Status is the state shown in Settings > Sources.
+func (f *Files) Status() map[string]any {
+	f.mu.Lock()
+	defer f.mu.Unlock()
+	list := make([]map[string]any, 0, len(f.cfg))
+	for _, s := range f.cfg {
+		m := map[string]any{
+			"id": s.ID, "name": s.Name, "path": s.Path, "format": s.Format, "regex": s.Regex,
+			"host": s.Host, "enabled": s.Enabled, "open": false, "read": 0, "detected": "", "behind": 0, "code": "", "error": "",
+		}
+		if st := f.status[s.ID]; st != nil && s.Enabled {
+			m["open"], m["read"], m["detected"], m["code"], m["error"] = st.Open, st.Read, st.Detected, st.Code, st.Error
+			m["behind"] = st.Behind
+		}
+		list = append(list, m)
+	}
+	return map[string]any{"sources": list, "defaultHost": f.hostName}
+}
+
+// Run polls the files every second.
+func (f *Files) Run(ctx context.Context) {
+	tick := time.NewTicker(time.Second)
+	defer tick.Stop()
+	n := 0
+	for {
+		select {
+		case <-ctx.Done():
+			now := time.Now()
+			for id := range f.tails {
+				f.flushPending(id, now)
+			}
+			f.checkpointAll()
+			f.saveState()
+			return
+		case <-tick.C:
+		case <-f.wake:
+		}
+		f.poll(time.Now())
+		if n++; n%5 == 0 {
+			f.saveState()
+		}
+	}
+}
+
+func (f *Files) saveState() {
+	if !f.dirty {
+		return
+	}
+	f.dirty = false
+	if err := writeJSONFile(f.statePath, f.st); err != nil {
+		logEvent("files", 4, "saving positions: %v", err)
+	}
+}
+
+// poll reads what was added to every file that is on.
+func (f *Files) poll(now time.Time) {
+	f.mu.Lock()
+	srcs := f.cfg
+	resets, redetect := f.resets, f.redetect
+	f.resets, f.redetect = map[string]bool{}, map[string]bool{}
+	f.mu.Unlock()
+	for id := range resets {
+		delete(f.st.Pos, id)
+		delete(f.st.Started, id)
+		delete(f.tails, id)
+		f.dirty = true
+	}
+	for id := range redetect {
+		if tl := f.tails[id]; tl != nil {
+			tl.auto = nil
+		}
+	}
+	active := map[string]bool{}
+	for _, s := range srcs {
+		if !s.Enabled {
+			continue
+		}
+		active[s.ID] = true
+		f.setStatus(s.ID, f.pollFile(s, now))
+	}
+	// Files turned off: their position is kept until the next poll forgets it.
+	for id := range f.tails {
+		if !active[id] {
+			delete(f.tails, id)
+		}
+	}
+	f.checkpointAll()
+}
+
+const (
+	maxFileRead       = 4 << 20         // per read
+	maxFileReads      = 16              // reads per file and per poll (64 MB)
+	fileContinueDelay = 2 * time.Second // an entry waits this long for continuation lines
+)
+
+func (f *Files) setStatus(id string, err error) {
+	code, detail := "", ""
+	if err != nil {
+		code, detail = errCode(err), err.Error()
+		if errors.Is(err, fs.ErrNotExist) {
+			code = "not_found"
+		}
+	}
+	detected := ""
+	if tl := f.tails[id]; tl != nil && tl.auto != nil {
+		detected = tl.auto.format
+	}
+	f.mu.Lock()
+	st := f.status[id]
+	if st == nil {
+		st = &fileSourceStatus{}
+		f.status[id] = st
+	}
+	changed := code != st.Code
+	st.Open, st.Detected, st.Code, st.Error = err == nil, detected, code, detail
+	st.Behind = 0
+	if tl := f.tails[id]; tl != nil && err == nil {
+		st.Behind = tl.behind
+	}
+	name := id
+	for _, s := range f.cfg {
+		if s.ID == id {
+			name = s.Name
+		}
+	}
+	f.mu.Unlock()
+	if changed && code != "" && code != "not_found" {
+		logEvent("files", 4, "cannot read the file %s: %v", name, err)
+	}
+}
+
+func (f *Files) count(id string) {
+	f.mu.Lock()
+	st := f.status[id]
+	if st == nil { // first poll of the file: its status comes after
+		st = &fileSourceStatus{}
+		f.status[id] = st
+	}
+	st.Read++
+	f.mu.Unlock()
+}
+
+// parserOf is the parser of a file: the chosen format, or the one detected
+// from its last lines (nil while the file has none).
+func (f *Files) parserOf(s *fileSource, tl *fileTail, path string) *fileParser {
+	if s.parser != nil {
+		return s.parser
+	}
+	if tl.auto == nil {
+		lines, err := sampleLines(path)
+		if err != nil || len(lines) == 0 {
+			return nil
+		}
+		tl.auto, _ = newFileParser(detectFormat(lines), "")
+	}
+	return tl.auto
+}
+
+func (f *Files) pollFile(s *fileSource, now time.Time) error {
+	path := s.Path
+	first := false
+	if _, ok := f.st.Started[s.ID]; !ok {
+		f.st.Started[s.ID], f.dirty, first = now, true, true
+	}
+	fi, err := os.Stat(path)
+	if err != nil {
+		return err
+	}
+	if !fi.Mode().IsRegular() {
+		return fmt.Errorf("%s is not a regular file", path)
+	}
+	tl := f.tails[s.ID]
+	if tl == nil {
+		tl = &fileTail{}
+		f.tails[s.ID] = tl
+	}
+	ino := inodeOf(fi)
+	pos, known := f.st.Pos[s.ID]
+	if !known {
+		pos = filePos{Ino: ino}
+		if first {
+			// Turned on: the last FILES_BACKFILL of what is already there
+			// (0: only new lines), found by date rather than read from the
+			// start of a file that can hold months of logs.
+			pos.Off = fi.Size()
+			if p := f.parserOf(s, tl, path); f.backfill > 0 && p != nil {
+				pos.Off = backfillStart(path, p, fi.Size(), f.st.Started[s.ID].Add(-f.backfill), now)
+				pos.Until = fi.Size()
+			}
+		}
+		f.st.Pos[s.ID], f.dirty = pos, true
+	}
+	if !tl.known {
+		tl.readOff, tl.known = pos.Off, true
+	}
+	if pos.Ino != ino {
+		// Rotated (access.log -> access.log.1): finish the old file, then
+		// read the new one from its start.
+		if old, err := os.Stat(path + ".1"); err == nil && inodeOf(old) == pos.Ino {
+			if p := f.parserOf(s, tl, path+".1"); p != nil {
+				for {
+					next, more, err := f.readFrom(s, tl, p, path+".1", tl.readOff, pos.Until, now)
+					if err != nil || !more {
+						break
+					}
+					tl.readOff = next
+				}
+			}
+		}
+		f.flushPending(s.ID, now)
+		pos, tl.readOff = filePos{Ino: ino}, 0
+		f.st.Pos[s.ID], f.dirty = pos, true
+	} else if fi.Size() < tl.readOff {
+		f.flushPending(s.ID, now) // truncated (copytruncate)
+		pos.Until, tl.readOff = 0, 0
+		f.st.Pos[s.ID], f.dirty = pos, true
+	}
+	if fi.Size() > tl.readOff {
+		p := f.parserOf(s, tl, path)
+		if p == nil {
+			return nil // nothing complete to detect the format from yet
+		}
+		for i := 0; i < maxFileReads; i++ {
+			next, more, err := f.readFrom(s, tl, p, path, tl.readOff, pos.Until, now)
+			if err != nil {
+				return err
+			}
+			tl.readOff = next
+			if !more {
+				break
+			}
+		}
+	}
+	tl.behind = max(fi.Size()-tl.readOff, 0)
+	if pe := tl.pending; pe != nil && now.Sub(pe.seen) >= fileContinueDelay {
+		f.flushPending(s.ID, now)
+	}
+	return nil
+}
+
+// backfillStart finds where the lines dated notBefore or later start, by
+// bisection on the dates of the lines (logs are written in order). Undated
+// lines are left out of the history anyway: then only new lines are read.
+func backfillStart(path string, p *fileParser, size int64, notBefore, now time.Time) int64 {
+	fh, err := os.Open(path)
+	if err != nil {
+		return size
+	}
+	defer fh.Close()
+	buf := make([]byte, 64<<10)
+	// lineAt reads the first line starting at or after off (off itself when
+	// it is 0): its start and its date.
+	lineAt := func(off int64) (int64, time.Time, bool) {
+		n, _ := fh.ReadAt(buf, off)
+		b := buf[:n]
+		start := off
+		if off > 0 {
+			nl := bytes.IndexByte(b, '\n')
+			if nl < 0 {
+				return size, time.Time{}, false
+			}
+			b, start = b[nl+1:], off+int64(nl)+1
+		}
+		end := bytes.IndexByte(b, '\n')
+		if end < 0 {
+			return size, time.Time{}, false
+		}
+		r := p.parse(string(b[:end]), now)
+		return start, r.t, r.dated
+	}
+	if _, t, ok := lineAt(0); !ok || !t.Before(notBefore) {
+		if !ok {
+			// No date on the first line: try the last ones.
+			if _, _, ok := lineAt(max(size-int64(len(buf)), 0)); !ok {
+				return size
+			}
+		} else {
+			return 0 // all of it is recent
+		}
+	}
+	lo, hi := int64(0), size // line at lo: before notBefore; at hi: not
+	for hi-lo > int64(len(buf)) {
+		mid := lo + (hi-lo)/2
+		_, t, ok := lineAt(mid)
+		if ok && t.Before(notBefore) {
+			lo = mid
+		} else {
+			hi = mid
+		}
+	}
+	start, _, _ := lineAt(lo)
+	return min(start, size)
+}
+
+// readFrom parses the complete lines written after off and returns the new
+// offset; more tells whether the read window was full.
+func (f *Files) readFrom(s *fileSource, tl *fileTail, p *fileParser, path string, off, until int64, now time.Time) (int64, bool, error) {
+	fh, err := os.Open(path)
+	if err != nil {
+		return off, false, err
+	}
+	defer fh.Close()
+	buf, err := io.ReadAll(io.NewSectionReader(fh, off, maxFileRead))
+	if err != nil {
+		return off, false, err
+	}
+	full := len(buf) == maxFileRead
+	end := bytes.LastIndexByte(buf, '\n')
+	if end < 0 {
+		if !full {
+			return off, false, nil // partial line: wait for its end
+		}
+		end = len(buf) - 1 // line longer than the read window: cut it
+	}
+	start := off
+	for _, b := range bytes.Split(buf[:end], []byte{'\n'}) {
+		f.line(s, tl, p, string(b), start, start < until, now)
+		start += int64(len(b)) + 1
+	}
+	return off + int64(end) + 1, full, nil
+}
+
+// line handles one line: a continuation of the pending entry, or a new one.
+func (f *Files) line(s *fileSource, tl *fileTail, p *fileParser, line string, off int64, history bool, now time.Time) {
+	if strings.TrimSpace(line) == "" {
+		return
+	}
+	if pe := tl.pending; p.multiline() && pe != nil && p.continuation(line) {
+		if pe.lines < maxContinuation && len(pe.rec.msg) < maxFileMsg {
+			pe.rec.msg += "\n" + strings.TrimRight(cleanLine(line), " \t")
+			pe.lines++
+		}
+		pe.seen = now
+		return
+	}
+	f.flushPending(s.ID, now)
+	pe := &pendingEntry{rec: p.parse(line, now), off: off, seen: now, history: history}
+	if p.multiline() {
+		tl.pending = pe
+		return
+	}
+	f.emit(s, pe, now)
+}
+
+func (f *Files) flushPending(id string, now time.Time) {
+	tl := f.tails[id]
+	if tl == nil || tl.pending == nil {
+		return
+	}
+	pe := tl.pending
+	tl.pending = nil
+	f.mu.Lock()
+	var src *fileSource
+	for _, s := range f.cfg {
+		if s.ID == id {
+			src = s
+		}
+	}
+	f.mu.Unlock()
+	if src != nil {
+		f.emit(src, pe, now)
+	}
+}
+
+// emit sends an entry; history entries are kept only when dated within
+// FILES_BACKFILL of when the file was turned on.
+func (f *Files) emit(s *fileSource, pe *pendingEntry, now time.Time) {
+	r := pe.rec
+	if pe.history {
+		notBefore := f.st.Started[s.ID].Add(-f.backfill)
+		if !r.dated || r.t.Before(notBefore) {
+			return
+		}
+	}
+	if len(r.msg) > maxFileMsg {
+		r.msg = strings.ToValidUTF8(r.msg[:maxFileMsg], "") + "…"
+	}
+	extra := map[string]string{"log_file": s.Path}
+	for k, v := range r.fields {
+		extra[k] = v
+	}
+	f.sink(&Entry{
+		Time:       r.t,
+		Received:   now,
+		Host:       firstNonEmpty(r.host, s.Host, f.hostName),
+		App:        firstNonEmpty(r.app, s.Name),
+		SevNum:     r.sev,
+		Severity:   severityNames[r.sev],
+		Message:    r.msg,
+		Proto:      "file",
+		SourceType: "file",
+		Extra:      extra,
+		Wait:       true, // the file keeps the lines: wait for room in the queue
+	})
+	f.count(s.ID)
+}
+
+// checkpointAll saves, for each file, an offset before which every entry is
+// sent: the start of its pending entry, or the read offset.
+func (f *Files) checkpointAll() {
+	for id, tl := range f.tails {
+		pos, ok := f.st.Pos[id]
+		if !ok || !tl.known {
+			continue
+		}
+		off := tl.readOff
+		if pe := tl.pending; pe != nil && pe.off < off {
+			off = pe.off
+		}
+		if off != pos.Off {
+			pos.Off, f.dirty = off, true
+			f.st.Pos[id] = pos
+		}
+	}
+}
+
+// DetectFile tells, for the settings, whether a file can be read and its
+// format, with a line as example.
+func DetectFile(path string) map[string]any {
+	res := map[string]any{"format": "", "sample": "", "code": "", "error": ""}
+	p, err := checkFilePath(path)
+	if err != nil {
+		res["code"], res["error"] = "invalid", err.Error()
+		return res
+	}
+	var lines []string
+	if fi, err2 := os.Stat(p); err2 != nil {
+		err = err2
+	} else if !fi.Mode().IsRegular() {
+		err = fmt.Errorf("%s is not a regular file", p)
+	} else {
+		lines, err = sampleLines(p)
+	}
+	switch {
+	case errors.Is(err, fs.ErrNotExist):
+		res["code"], res["error"] = "not_found", err.Error()
+	case err != nil:
+		res["code"], res["error"] = errCode(err), err.Error()
+	case len(lines) == 0:
+		res["code"] = "empty"
+	default:
+		res["format"] = detectFormat(lines)
+		sample := lines[len(lines)-1]
+		if len(sample) > 300 {
+			sample = strings.ToValidUTF8(sample[:300], "") + "…"
+		}
+		res["sample"] = cleanLine(sample)
+	}
+	return res
+}

filesource_test.go

@@ -0,0 +1,427 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"testing"
+	"time"
+)
+
+func mustParser(t *testing.T, format, expr string) *fileParser {
+	t.Helper()
+	p, err := newFileParser(format, expr)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return p
+}
+
+func TestParseLogTime(t *testing.T) {
+	now := time.Date(2026, 10, 5, 12, 0, 0, 0, time.UTC)
+	utc := func(s string) time.Time { t, _ := time.Parse(time.RFC3339Nano, s); return t }
+	tests := []struct {
+		in   string
+		want time.Time
+	}{
+		{"2026-10-05T10:00:00.123Z", utc("2026-10-05T10:00:00.123Z")},
+		{"2026-10-05T10:00:00+02:00", utc("2026-10-05T08:00:00Z")},
+		{"2026-10-05 10:00:00,250 +0200", utc("2026-10-05T08:00:00.25Z")},
+		{"2026/10/05 10:00:00Z", utc("2026-10-05T10:00:00Z")},
+		{"05/Oct/2026:10:00:00 +0200", utc("2026-10-05T08:00:00Z")},
+		{"1759572000", time.Unix(1759572000, 0)},
+		{"1759572000123", time.UnixMilli(1759572000123)},
+	}
+	for _, tt := range tests {
+		got, ok := parseLogTime(tt.in, now)
+		if !ok || !got.Equal(tt.want) {
+			t.Errorf("%q: got %v %v, want %v", tt.in, got, ok, tt.want)
+		}
+	}
+	// Syslog timestamps: no year, the last one before tomorrow.
+	if got, ok := parseLogTime("Dec 31 23:00:00", now); !ok || got.Year() != 2025 {
+		t.Errorf("Dec 31: %v %v", got, ok)
+	}
+	if got, ok := parseLogTime("Oct  5 11:00:00", now); !ok || got.Year() != 2026 || got.Day() != 5 {
+		t.Errorf("Oct 5: %v %v", got, ok)
+	}
+	for _, bad := range []string{"", "hello", "200", "12345"} {
+		if _, ok := parseLogTime(bad, now); ok {
+			t.Errorf("%q parsed", bad)
+		}
+	}
+}
+
+func TestParseText(t *testing.T) {
+	now := time.Now()
+	p := mustParser(t, fmtText, "")
+	r := p.parse("2026-10-05 10:00:00.5 ERROR db: connection refused", now)
+	if !r.dated || r.msg != "ERROR db: connection refused" || r.sev != 3 {
+		t.Errorf("got %+v", r)
+	}
+	r = p.parse("[2026-10-05T10:00:00Z] - started", now)
+	if !r.dated || r.msg != "started" || r.sev != 6 {
+		t.Errorf("got %+v", r)
+	}
+	r = p.parse("\x1b[33mWARN\x1b[0m no timestamp here", now)
+	if r.dated || r.msg != "WARN no timestamp here" || r.sev != 4 || !r.t.Equal(now) {
+		t.Errorf("got %+v", r)
+	}
+}
+
+func TestParseJSON(t *testing.T) {
+	now := time.Now()
+	p := mustParser(t, fmtJSON, "")
+	r := p.parse(`{"time":"2026-10-05T10:00:00Z","level":"warn","msg":"slow query","host":"db.example","req":{"id":7,"tags":["a"]},"ok":true}`, now)
+	if !r.dated || r.sev != 4 || r.msg != "slow query" {
+		t.Errorf("got %+v", r)
+	}
+	for k, want := range map[string]string{"field_host": "db.example", "req.id": "7", "req.tags": `["a"]`, "ok": "true"} {
+		if r.fields[k] != want {
+			t.Errorf("%s = %q, want %q", k, r.fields[k], want)
+		}
+	}
+	// pino: numeric level, epoch in ms.
+	r = p.parse(`{"level":50,"time":1759572000123,"msg":"boom"}`, now)
+	if r.sev != 3 || !r.t.Equal(time.UnixMilli(1759572000123)) {
+		t.Errorf("got %+v", r)
+	}
+	// No message key: the whole line; not JSON: text.
+	line := `{"event":"login","user":"bob"}`
+	if r = p.parse(line, now); r.msg != line || r.fields["user"] != "bob" {
+		t.Errorf("got %+v", r)
+	}
+	if r = p.parse("plain ERROR line", now); r.msg != "plain ERROR line" || r.sev != 3 {
+		t.Errorf("got %+v", r)
+	}
+}
+
+func TestParseLogfmt(t *testing.T) {
+	p := mustParser(t, fmtLogfmt, "")
+	r := p.parse(`time="2026-10-05T10:00:00Z" level=error msg="Cannot connect: \"docker\" down" providerName=docker flag`, time.Now())
+	if !r.dated || r.sev != 3 || r.msg != `Cannot connect: "docker" down` || r.fields["providerName"] != "docker" {
+		t.Errorf("got %+v", r)
+	}
+}
+
+func TestParseRegex(t *testing.T) {
+	if _, err := newFileParser(fmtRegex, "("); err == nil {
+		t.Error("invalid regex accepted")
+	}
+	if _, err := newFileParser(fmtRegex, ""); err == nil {
+		t.Error("empty regex accepted")
+	}
+	p := mustParser(t, fmtRegex, `^(?P<time>\S+ \S+) \[(?P<level>\w+)\] (?P<module>[\w.]+): (?P<msg>.*)$`)
+	r := p.parse("2026-10-05 10:00:00 [warning] app.db: pool exhausted", time.Now())
+	if !r.dated || r.sev != 4 || r.msg != "pool exhausted" || r.fields["module"] != "app.db" {
+		t.Errorf("got %+v", r)
+	}
+	if !p.continuation("Traceback (most recent call last):") || p.continuation("2026-10-05 10:00:01 [info] a: b") {
+		t.Error("continuation")
+	}
+}
+
+func TestParseCLF(t *testing.T) {
+	p := mustParser(t, fmtCLF, "")
+	r := p.parse(`203.0.113.9 - - [05/Oct/2026:10:00:00 +0200] "GET /api/x?y=1 HTTP/1.1" 502 157 "-" "curl/8.0" 4211 "api@docker" "http://172.18.0.5:8080" 31ms`, time.Now())
+	if !r.dated || r.sev != 3 || !strings.HasPrefix(r.msg, "203.0.113.9 - - [") {
+		t.Errorf("got %+v", r)
+	}
+	for k, want := range map[string]string{"client_ip": "203.0.113.9", "http_method": "GET", "http_path": "/api/x?y=1", "http_status": "502",
+		"user_agent": "curl/8.0", "router": "api@docker", "backend": "http://172.18.0.5:8080", "duration_ms": "31"} {
+		if r.fields[k] != want {
+			t.Errorf("%s = %q, want %q", k, r.fields[k], want)
+		}
+	}
+	if _, ok := r.fields["http_referer"]; ok {
+		t.Error("empty referer kept")
+	}
+	// nginx combined, 404.
+	r = p.parse(`10.0.0.1 - alice [05/Oct/2026:10:00:00 +0000] "POST /login HTTP/2.0" 404 0 "https://example.com/" "Mozilla/5.0"`, time.Now())
+	if r.sev != 4 || r.fields["http_user"] != "alice" || r.fields["http_referer"] != "https://example.com/" {
+		t.Errorf("got %+v", r)
+	}
+}
+
+func TestParseTraefikJSON(t *testing.T) {
+	p := mustParser(t, fmtTraefik, "")
+	r := p.parse(`{"ClientHost":"203.0.113.9","DownstreamStatus":200,"Duration":12500000,"RequestHost":"app.example.com","RequestMethod":"GET","RequestPath":"/","RequestProtocol":"HTTP/2.0","RouterName":"app@docker","StartUTC":"2026-10-05T10:00:00.1Z","entryPointName":"websecure","level":"info","msg":"","time":"2026-10-05T10:00:00Z","TLSVersion":"1.3"}`, time.Now())
+	if !r.dated || r.sev != 6 || r.msg != "GET app.example.com/ 200 · 12.5 ms · app@docker · 203.0.113.9" {
+		t.Errorf("got %+v", r)
+	}
+	for k, want := range map[string]string{"entrypoint": "websecure", "http_status": "200", "TLSVersion": "1.3", "duration_ms": "12.5"} {
+		if r.fields[k] != want {
+			t.Errorf("%s = %q, want %q", k, r.fields[k], want)
+		}
+	}
+	// Traefik's own logs in the same file: generic JSON.
+	r = p.parse(`{"level":"error","msg":"Provider error","time":"2026-10-05T10:00:00Z"}`, time.Now())
+	if r.sev != 3 || r.msg != "Provider error" {
+		t.Errorf("got %+v", r)
+	}
+}
+
+func TestDetectFormat(t *testing.T) {
+	tests := map[string][]string{
+		fmtJSON:    {`{"level":"info","msg":"a"}`, `{"level":"warn","msg":"b"}`},
+		fmtTraefik: {`{"RequestMethod":"GET","DownstreamStatus":200}`, `{"level":"info","msg":"Configuration loaded"}`},
+		fmtCLF:     {`10.0.0.1 - - [05/Oct/2026:10:00:00 +0000] "GET / HTTP/1.1" 200 12 "-" "curl"`},
+		fmtLogfmt:  {`time="2026-10-05T10:00:00Z" level=info msg="Starting provider" providerName=docker`},
+		fmtText:    {`2026-10-05 10:00:00 INFO started`, `user=bob logged in`},
+	}
+	for want, lines := range tests {
+		if got := detectFormat(lines); got != want {
+			t.Errorf("%q: got %s, want %s", lines, got, want)
+		}
+	}
+	// A few lines of another format do not change the answer (80 %).
+	lines := []string{`{"a":1}`, `{"a":2}`, `{"a":3}`, `{"a":4}`, `not json`}
+	if got := detectFormat(lines); got != fmtJSON {
+		t.Errorf("got %s", got)
+	}
+	lines = append(lines, `still not json`)
+	if got := detectFormat(lines); got != fmtText {
+		t.Errorf("got %s", got)
+	}
+}
+
+func TestDetectFile(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "access.log")
+	appendFile(t, path, `10.0.0.1 - - [05/Oct/2026:10:00:00 +0000] "GET / HTTP/1.1" 200 12 "-" "curl"`+"\n"+`partial`)
+	res := DetectFile(path)
+	if res["format"] != fmtCLF || !strings.HasPrefix(res["sample"].(string), "10.0.0.1 - -") || res["code"] != "" {
+		t.Errorf("got %+v", res)
+	}
+	for p, code := range map[string]string{
+		filepath.Join(dir, "nope.log"): "not_found", "relative.log": "invalid", filepath.Join(dir, "*.log"): "invalid", dir: "read",
+	} {
+		if res := DetectFile(p); res["code"] != code {
+			t.Errorf("%s: got %+v, want %s", p, res, code)
+		}
+	}
+	empty := filepath.Join(dir, "empty.log")
+	appendFile(t, empty, "")
+	if res := DetectFile(empty); res["code"] != "empty" {
+		t.Errorf("got %+v", res)
+	}
+}
+
+func TestFileSourceValidation(t *testing.T) {
+	f := NewFiles(t.TempDir(), t.TempDir(), time.Hour, func(*Entry) {})
+	bad := []fileSourceDef{
+		{Name: "", Path: "/logs/a.log"},
+		{Name: "a", Path: "relative.log"},
+		{Name: "a", Path: "/logs/*.log"},
+		{Name: "a", Path: "/logs/a.log", Format: "xml"},
+		{Name: "a", Path: "/logs/a.log", Format: fmtRegex, Regex: "(?P<x"},
+	}
+	for _, d := range bad {
+		if err := f.Configure(filesConfig{Sources: []fileSourceDef{d}}); err == nil {
+			t.Errorf("%+v accepted", d)
+		}
+	}
+	if err := f.Configure(filesConfig{Sources: []fileSourceDef{{Name: " traefik ", Path: "/logs/traefik/access.log"}}}); err != nil {
+		t.Fatal(err)
+	}
+	src := f.Status()["sources"].([]map[string]any)
+	if len(src) != 1 || src[0]["name"] != "traefik" || src[0]["id"] == "" || src[0]["format"] != fmtAuto {
+		t.Errorf("got %+v", src)
+	}
+}
+
+type fileSink struct {
+	mu sync.Mutex
+	e  []*Entry
+}
+
+func (s *fileSink) add(e *Entry) { s.mu.Lock(); s.e = append(s.e, e); s.mu.Unlock() }
+func (s *fileSink) take() []*Entry {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	e := s.e
+	s.e = nil
+	return e
+}
+
+func appendFile(t *testing.T, path, s string) {
+	t.Helper()
+	fh, err := os.OpenFile(path, os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0o644)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := fh.WriteString(s); err != nil {
+		t.Fatal(err)
+	}
+	fh.Close()
+}
+
+func msgs(es []*Entry) []string {
+	var out []string
+	for _, e := range es {
+		out = append(out, e.Message)
+	}
+	return out
+}
+
+func TestFilesFollow(t *testing.T) {
+	dir, data := t.TempDir(), t.TempDir()
+	now := time.Now()
+	old := now.Add(-3 * time.Hour).UTC().Format(time.RFC3339)
+	recent := now.Add(-10 * time.Minute).UTC().Format(time.RFC3339)
+	app := filepath.Join(dir, "app.log")
+	appendFile(t, app, old+" INFO too old\n"+recent+" ERROR recent\n  at line 1\nundated history line\n")
+
+	sink := &fileSink{}
+	f := NewFiles(dir, data, time.Hour, sink.add)
+	if err := f.Configure(filesConfig{Sources: []fileSourceDef{{Name: "myapp", Path: app, Host: "web1", Enabled: true}}}); err != nil {
+		t.Fatal(err)
+	}
+	f.poll(now)
+	f.poll(now.Add(3 * time.Second)) // the pending entry waited for continuation lines
+	got := sink.take()
+	if len(got) != 1 || got[0].Message != "ERROR recent\n  at line 1" || got[0].SevNum != 3 || got[0].App != "myapp" ||
+		got[0].Host != "web1" || got[0].SourceType != "file" || got[0].Extra["log_file"] != app {
+		t.Fatalf("history: got %q %+v", msgs(got), got)
+	}
+	if st := f.Status()["sources"].([]map[string]any)[0]; st["detected"] != fmtText || st["open"] != true {
+		t.Errorf("status %+v", st)
+	}
+
+	appendFile(t, app, "plain new line\n\tcontinued\n")
+	f.poll(now.Add(4 * time.Second))
+	appendFile(t, app, "after\n")
+	f.poll(now.Add(5 * time.Second))
+	f.poll(now.Add(8 * time.Second))
+	if got = sink.take(); strings.Join(msgs(got), "|") != "plain new line\n\tcontinued|after" {
+		t.Fatalf("new lines: got %q", msgs(got))
+	}
+
+	appendFile(t, app, "before rotation\n")
+	if err := os.Rename(app, app+".1"); err != nil {
+		t.Fatal(err)
+	}
+	appendFile(t, app, "after rotation\n")
+	f.poll(now.Add(9 * time.Second))
+	f.poll(now.Add(12 * time.Second))
+	if got = sink.take(); strings.Join(msgs(got), "|") != "before rotation|after rotation" {
+		t.Fatalf("rotation: got %q", msgs(got))
+	}
+
+	// Restart: resumes where it stopped, nothing sent twice.
+	f.checkpointAll()
+	f.dirty = true
+	f.saveState()
+	appendFile(t, app, "while stopped\n")
+	f2 := NewFiles(dir, data, time.Hour, sink.add)
+	f2.poll(now.Add(13 * time.Second))
+	f2.poll(now.Add(16 * time.Second))
+	if got = sink.take(); strings.Join(msgs(got), "|") != "while stopped" {
+		t.Fatalf("restart: got %q", msgs(got))
+	}
+
+	// Truncated in place (copytruncate).
+	os.Truncate(app, 0)
+	appendFile(t, app, "x\n")
+	f2.poll(now.Add(17 * time.Second))
+	f2.poll(now.Add(20 * time.Second))
+	if got = sink.take(); strings.Join(msgs(got), "|") != "x" {
+		t.Fatalf("truncate: got %q", msgs(got))
+	}
+}
+
+func TestFilesAutoAndErrors(t *testing.T) {
+	dir, data := t.TempDir(), t.TempDir()
+	path := filepath.Join(dir, "access.json")
+	sink := &fileSink{}
+	f := NewFiles(dir, data, 0, sink.add) // FILES_BACKFILL=0: only new lines
+	cfg := filesConfig{Sources: []fileSourceDef{
+		{ID: "a1", Name: "api", Path: path, Enabled: true}, // auto
+		{ID: "b2", Name: "missing", Path: filepath.Join(dir, "nope.log"), Format: fmtText, Enabled: true},
+	}}
+	if err := f.Configure(cfg); err != nil {
+		t.Fatal(err)
+	}
+	now := time.Now()
+	appendFile(t, path, "")
+	f.poll(now) // empty file: format not known yet
+	appendFile(t, path, `{"msg":"one","level":"error"}`+"\n"+`{"msg":"two"}`+"\n"+`{"msg":"partial`)
+	f.poll(now.Add(time.Second))
+	got := sink.take()
+	if strings.Join(msgs(got), "|") != "one|two" || got[0].SevNum != 3 {
+		t.Fatalf("got %q", msgs(got))
+	}
+	src := f.Status()["sources"].([]map[string]any)
+	if src[0]["detected"] != fmtJSON || src[0]["open"] != true || src[1]["code"] != "not_found" {
+		t.Errorf("status %+v", src)
+	}
+
+	// Forced format: the JSON lines are read as text.
+	cfg.Sources[0].Format = fmtText
+	f.Configure(cfg)
+	appendFile(t, path, `"}`+"\n")
+	f.poll(now.Add(2 * time.Second))
+	f.poll(now.Add(5 * time.Second))
+	if got = sink.take(); strings.Join(msgs(got), "|") != `{"msg":"partial"}` {
+		t.Fatalf("forced: got %q", msgs(got))
+	}
+
+	// Turned off then on: starts over (only new lines here).
+	cfg.Sources[0].Enabled = false
+	f.Configure(cfg)
+	f.poll(now.Add(6 * time.Second))
+	appendFile(t, path, "while off\n")
+	cfg.Sources[0].Enabled = true
+	f.Configure(cfg)
+	f.poll(now.Add(7 * time.Second))
+	appendFile(t, path, "three\n")
+	f.poll(now.Add(8 * time.Second))
+	f.poll(now.Add(11 * time.Second))
+	if got = sink.take(); strings.Join(msgs(got), "|") != "three" {
+		t.Fatalf("re-enabled: got %q", msgs(got))
+	}
+}
+
+// A large access log: the last hour is found by date, not read from the
+// start, and every entry is counted from the first poll.
+func TestFilesBackfillLargeFile(t *testing.T) {
+	dir, data := t.TempDir(), t.TempDir()
+	path := filepath.Join(dir, "access.log")
+	now := time.Now()
+	line := func(at time.Time, n int) string {
+		return fmt.Sprintf(`86.246.223.62 - - [%s] "GET /wp-content/x.png HTTP/2.0" 200 640365 "-" "-" %d "vblog-io-router@file" "http://wordpress" 3ms`+"\n",
+			at.UTC().Format("02/Jan/2006:15:04:05 -0700"), n)
+	}
+	var b strings.Builder
+	const n = 200000 // one line every 3 s for a week: ~32 MB
+	for i := 0; i < n; i++ {
+		b.WriteString(line(now.Add(-time.Duration(n-i)*3*time.Second), i))
+	}
+	appendFile(t, path, b.String())
+	sink := &fileSink{}
+	f := NewFiles(dir, data, time.Hour, sink.add)
+	f.Configure(filesConfig{Sources: []fileSourceDef{{ID: "a1", Name: "traefik-log", Path: path, Enabled: true}}})
+	f.poll(now)
+	if pos := f.st.Pos["a1"]; pos.Off < int64(b.Len())*99/100 {
+		t.Errorf("history read from offset %d of %d", pos.Off, b.Len())
+	}
+	appendFile(t, path, line(now, n))
+	f.poll(now.Add(time.Second))
+	got := sink.take()
+	// The last hour (1200 lines, the oldest one on the edge) and the new line.
+	if len(got) < 1200 || len(got) > 1201 || got[0].App != "traefik-log" || got[len(got)-1].Extra["http_status"] != "200" {
+		t.Fatalf("got %d entries", len(got))
+	}
+	if st := f.Status()["sources"].([]map[string]any)[0]; st["read"] != uint64(len(got)) || st["behind"] != int64(0) || st["detected"] != fmtCLF {
+		t.Errorf("status %+v", st)
+	}
+	// Undated plain text: only new lines.
+	txt := filepath.Join(dir, "app.log")
+	appendFile(t, txt, strings.Repeat("no date here\n", 1000))
+	p := mustParser(t, fmtText, "")
+	if off := backfillStart(txt, p, 13000, now.Add(-time.Hour), now); off != 13000 {
+		t.Errorf("undated: %d", off)
+	}
+}

guard.go

@@ -0,0 +1,122 @@
+package main
+
+import (
+	"context"
+	"crypto/sha256"
+	"encoding/base64"
+	"io/fs"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+)
+
+// Request guards shared by every auth mode: security headers, a cross-site
+// request check, and the read-only role.
+
+type viewerKey struct{}
+
+// asViewer marks the request as made by a read-only user.
+func asViewer(r *http.Request) *http.Request {
+	return r.WithContext(context.WithValue(r.Context(), viewerKey{}, true))
+}
+
+func isViewer(r *http.Request) bool {
+	v, _ := r.Context().Value(viewerKey{}).(bool)
+	return v
+}
+
+func roleName(viewer bool) string {
+	if viewer {
+		return "viewer"
+	}
+	return "admin"
+}
+
+func isSafeMethod(m string) bool {
+	return m == http.MethodGet || m == http.MethodHead || m == http.MethodOptions
+}
+
+// readOnly refuses the API calls that change something (tags, sources, purge)
+// to read-only users. Without authentication everyone is admin.
+func readOnly(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if isViewer(r) && !isSafeMethod(r.Method) && strings.HasPrefix(r.URL.Path, "/api/") {
+			writeErr(w, http.StatusForbidden, &codedError{code: "read_only", msg: "read-only account: changes are reserved to administrators"})
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+// crossSite tells whether a request that changes something comes from another
+// site (a form or script on a third-party page), using the headers browsers
+// add; tools such as curl send neither and are let through.
+func crossSite(r *http.Request) bool {
+	switch r.Header.Get("Sec-Fetch-Site") {
+	case "same-origin", "none":
+		return false
+	case "":
+	default: // same-site, cross-site
+		return true
+	}
+	o := r.Header.Get("Origin")
+	if o == "" {
+		return false
+	}
+	u, err := url.Parse(o)
+	return err != nil || !strings.EqualFold(u.Host, r.Host)
+}
+
+// secure adds the security headers to every answer and refuses cross-site
+// changes. Without authentication it also answers /auth/me, so the UI can
+// warn that anyone on the network has full access.
+func secure(next http.Handler, csp string, authOn bool) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		h := w.Header()
+		h.Set("X-Content-Type-Options", "nosniff")
+		h.Set("X-Frame-Options", "DENY")
+		h.Set("Referrer-Policy", "same-origin")
+		h.Set("Content-Security-Policy", csp)
+		if !isSafeMethod(r.Method) && crossSite(r) {
+			writeErr(w, http.StatusForbidden, &codedError{code: "cross_site", msg: "cross-site request refused"})
+			return
+		}
+		if !authOn && r.URL.Path == "/auth/me" {
+			writeJSON(w, http.StatusOK, map[string]string{"mode": "none", "role": "admin"})
+			return
+		}
+		next.ServeHTTP(w, r)
+	})
+}
+
+var inlineScript = regexp.MustCompile(`(?s)<script>(.*?)</script>`)
+
+// contentSecurityPolicy allows the UI's own files, the inline scripts of the
+// embedded pages (by hash) and the optional Bunny Fonts.
+func contentSecurityPolicy(static fs.FS) string {
+	scripts := []string{"'self'"}
+	for _, page := range []string{"index.html", "login.html"} {
+		b, err := fs.ReadFile(static, page)
+		if err != nil {
+			continue
+		}
+		for _, m := range inlineScript.FindAllSubmatch(b, -1) {
+			sum := sha256.Sum256(m[1])
+			scripts = append(scripts, "'sha256-"+base64.StdEncoding.EncodeToString(sum[:])+"'")
+		}
+	}
+	return strings.Join([]string{
+		"default-src 'self'",
+		"script-src " + strings.Join(scripts, " "),
+		// Inline style attributes carry the tag and project colors.
+		"style-src 'self' 'unsafe-inline' https://fonts.bunny.net",
+		"font-src 'self' https://fonts.bunny.net",
+		"img-src 'self' data:",
+		"connect-src 'self'",
+		"object-src 'none'",
+		"base-uri 'none'",
+		"form-action 'self'",
+		"frame-ancestors 'none'",
+	}, "; ")
+}

guard_test.go

@@ -0,0 +1,168 @@
+package main
+
+import (
+	"errors"
+	"io/fs"
+	"net"
+	"net/http"
+	"net/http/cookiejar"
+	"net/http/httptest"
+	"os"
+	"strings"
+	"testing"
+	"time"
+)
+
+var echo = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { _, _ = w.Write([]byte("app " + r.URL.Path)) })
+
+func TestSecureHeadersAndCrossSite(t *testing.T) {
+	h := secure(echo, "default-src 'self'", false)
+	cases := []struct {
+		method string
+		hdr    map[string]string
+		want   int
+	}{
+		{"GET", map[string]string{"Sec-Fetch-Site": "cross-site"}, 200}, // reading is fine
+		{"POST", nil, 200}, // curl, scripts
+		{"POST", map[string]string{"Sec-Fetch-Site": "same-origin"}, 200},
+		{"POST", map[string]string{"Sec-Fetch-Site": "cross-site"}, 403},
+		{"DELETE", map[string]string{"Sec-Fetch-Site": "same-site"}, 403},
+		{"POST", map[string]string{"Origin": "http://logs.lan:8080"}, 200},
+		{"POST", map[string]string{"Origin": "https://evil.example"}, 403},
+		{"PUT", map[string]string{"Origin": "null"}, 403},
+	}
+	for _, c := range cases {
+		r := httptest.NewRequest(c.method, "http://logs.lan:8080/api/purge", nil)
+		for k, v := range c.hdr {
+			r.Header.Set(k, v)
+		}
+		rec := httptest.NewRecorder()
+		h.ServeHTTP(rec, r)
+		if rec.Code != c.want {
+			t.Errorf("%s %v: %d, want %d", c.method, c.hdr, rec.Code, c.want)
+		}
+		if rec.Header().Get("Content-Security-Policy") == "" || rec.Header().Get("X-Frame-Options") != "DENY" {
+			t.Errorf("%s %v: security headers missing", c.method, c.hdr)
+		}
+	}
+
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, httptest.NewRequest("GET", "/auth/me", nil))
+	if !strings.Contains(rec.Body.String(), `"mode":"none"`) || !strings.Contains(rec.Body.String(), `"role":"admin"`) {
+		t.Errorf("/auth/me without auth: %s", rec.Body)
+	}
+	rec = httptest.NewRecorder()
+	secure(echo, "", true).ServeHTTP(rec, httptest.NewRequest("GET", "/auth/me", nil))
+	if rec.Body.String() != "app /auth/me" {
+		t.Errorf("/auth/me with auth answered by the guard: %s", rec.Body)
+	}
+}
+
+func TestContentSecurityPolicyHashesInlineScripts(t *testing.T) {
+	static, _ := fs.Sub(webFS, "web")
+	csp := contentSecurityPolicy(static)
+	// index.html and login.html each have inline scripts.
+	if n := strings.Count(csp, "'sha256-"); n < 3 {
+		t.Errorf("%d script hashes in %q", n, csp)
+	}
+	for _, want := range []string{"frame-ancestors 'none'", "connect-src 'self'", "https://fonts.bunny.net"} {
+		if !strings.Contains(csp, want) {
+			t.Errorf("CSP lacks %q", want)
+		}
+	}
+}
+
+func TestLocalViewerIsReadOnly(t *testing.T) {
+	loginFailDelay = 0
+	h, err := newAuth(authConfig{mode: "local", user: "admin", pass: "pw", viewerUser: "guest", viewerPass: "ro", dataDir: t.TempDir()}, readOnly(echo))
+	if err != nil {
+		t.Fatal(err)
+	}
+	jar, _ := cookiejar.New(nil)
+	c := &http.Client{Jar: jar, Transport: hosts{"app.test": h}, CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }}
+	app := "http://app.test"
+
+	login(t, c, app, "guest", "ro", "/")
+	if code, body := get(t, c, app+"/auth/me"); code != 200 || !strings.Contains(body, `"role":"viewer"`) {
+		t.Fatalf("me: %d %s", code, body)
+	}
+	if code, _ := get(t, c, app+"/api/logs"); code != 200 {
+		t.Errorf("viewer reading logs: %d", code)
+	}
+	res, err := c.Post(app+"/api/purge", "application/json", strings.NewReader(`{"confirm":"PURGE"}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	if res.StatusCode != http.StatusForbidden {
+		t.Errorf("viewer purge: %d, want 403", res.StatusCode)
+	}
+
+	// The admin account still changes things, also through Basic auth.
+	req, _ := http.NewRequest("PUT", app+"/api/syslog", strings.NewReader("{}"))
+	req.SetBasicAuth("admin", "pw")
+	if res, _ := (&http.Client{Transport: hosts{"app.test": h}}).Do(req); res.StatusCode != 200 {
+		t.Errorf("admin change: %d", res.StatusCode)
+	}
+	req, _ = http.NewRequest("PUT", app+"/api/syslog", strings.NewReader("{}"))
+	req.SetBasicAuth("guest", "ro")
+	if res, _ := (&http.Client{Transport: hosts{"app.test": h}}).Do(req); res.StatusCode != http.StatusForbidden {
+		t.Errorf("viewer change through Basic auth: %d", res.StatusCode)
+	}
+}
+
+func TestOIDCAdminGroup(t *testing.T) {
+	for _, tc := range []struct {
+		groups any
+		role   string
+	}{
+		{[]any{"staff", "/logstream-admins"}, "admin"},
+		{[]any{"staff"}, "viewer"},
+		{nil, "viewer"},
+	} {
+		idp := newFakeIdP(t)
+		idp.claims = func(c map[string]any) {
+			if tc.groups != nil {
+				c["groups"] = tc.groups
+			}
+		}
+		h, err := newAuth(authConfig{
+			mode: "oidc", issuer: "http://idp.test/realm", clientID: "logstream", clientSecret: "s3cret",
+			redirectURL: "http://app.test/auth/callback", dataDir: t.TempDir(), adminGroup: "logstream-admins",
+		}, readOnly(echo))
+		if err != nil {
+			t.Fatal(err)
+		}
+		netw := hosts{"app.test": h, "idp.test": idp.mux}
+		h.(*OIDC).client.Transport = netw
+		jar, _ := cookiejar.New(nil)
+		c := &http.Client{Jar: jar, Transport: netw}
+		get(t, c, "http://app.test/")
+		if _, body := get(t, c, "http://app.test/auth/me"); !strings.Contains(body, `"role":"`+tc.role+`"`) {
+			t.Errorf("groups %v: %s, want role %s", tc.groups, body, tc.role)
+		}
+	}
+}
+
+func TestHasGroup(t *testing.T) {
+	if !hasGroup("ops logstream-admins", "/logstream-admins") || !hasGroup([]any{"a", "b"}, "b") || hasGroup(42, "b") {
+		t.Error("hasGroup")
+	}
+}
+
+func TestTCPIdleTimeout(t *testing.T) {
+	a, b := net.Pipe()
+	defer b.Close()
+	c := idleConn{a, 30 * time.Millisecond}
+	go func() { _, _ = b.Write([]byte("x")) }()
+	buf := make([]byte, 1)
+	if _, err := c.Read(buf); err != nil {
+		t.Fatal(err)
+	}
+	start := time.Now()
+	if _, err := c.Read(buf); !errors.Is(err, os.ErrDeadlineExceeded) {
+		t.Fatalf("silent connection: %v, want a deadline error", err)
+	}
+	if time.Since(start) > time.Second {
+		t.Error("deadline not applied")
+	}
+}

histogram_test.go

@@ -153,7 +153,7 @@ func TestHistogramHandler(t *testing.T) {
 {"_time":"2000-01-01T00:00:00Z","severity":"info","hits":"9"}
 `, recent.Format(time.RFC3339), recent.Format(time.RFC3339), older.Format(time.RFC3339))
 	}}
-	store := NewStore("http://vl", 10, 10, time.Second)
+	store := NewStore("http://vl", 10, 10, time.Second, nil)
 	store.streamClient.Transport = vl
 	a := &API{store: store}
 
@@ -207,7 +207,7 @@ func TestHistogramDayInParis(t *testing.T) {
 {"_time":"2026-09-21T20:00:00Z","severity":"info","hits":"100"}
 `
 	}}
-	store := NewStore("http://vl", 10, 10, time.Second)
+	store := NewStore("http://vl", 10, 10, time.Second, nil)
 	store.streamClient.Transport = vl
 	a := &API{store: store}
 	from := time.Date(2026, 9, 10, 0, 0, 0, 0, time.UTC)

hostlogs.go

@@ -7,7 +7,6 @@ import (
 	"errors"
 	"io"
 	"io/fs"
-	"log"
 	"os"
 	"path/filepath"
 	"sort"
@@ -116,14 +115,18 @@ func (h *HostLogs) saveState() {
 	}
 	h.dirty = false
 	if err := writeJSONFile(h.statePath, h.pos); err != nil {
-		log.Printf("host logs: saving positions: %v", err)
+		logEvent("host", 4, "saving positions: %v", err)
 	}
 }
 
 func (h *HostLogs) setStatus(mode string, files int, code, detail string) {
 	h.mu.Lock()
+	changed := code != h.errCode
 	h.mode, h.files, h.errCode, h.errDetail = mode, files, code, detail
 	h.mu.Unlock()
+	if changed && code != "" && code != "empty" {
+		logEvent("host", 4, "cannot read the host system logs (%s): %s", code, detail)
+	}
 }
 
 // scan reads what was added since the previous poll.
@@ -327,6 +330,7 @@ func (h *HostLogs) readFile(path, name string, off int64) (int64, error) {
 		}
 		e.SourceType = "host"
 		e.Extra = map[string]string{"log_file": "/var/log/" + name}
+		e.Wait = true
 		h.sink(e)
 		h.count(1, 0)
 	}
@@ -400,6 +404,7 @@ func (h *HostLogs) emitJournal(je *journalEntry) {
 		Proto:      "journal",
 		SourceType: "host",
 		Extra:      map[string]string{"unit": f["_SYSTEMD_UNIT"]},
+		Wait:       true,
 	})
 }
 

main.go

@@ -38,9 +38,16 @@ type config struct {
 	backfill   time.Duration
 	hostRoot   string
 	hostFill   time.Duration
+	kmsgDevice string
+	kmsgFill   time.Duration
+	auditLog   string
+	auditHost  string
+	auditFill  time.Duration
+	filesFill  time.Duration
 	batchSize  int
 	queueSize  int
 	flushEvery time.Duration
+	spoolMax   int64
 }
 
 func getenv(key, def string) string {
@@ -57,6 +64,14 @@ func getenvInt(key string, def int) int {
 	return def
 }
 
+// getenvIntZero is getenvInt that also accepts 0 (to turn a feature off).
+func getenvIntZero(key string, def int) int {
+	if v, err := strconv.Atoi(os.Getenv(key)); err == nil && v >= 0 {
+		return v
+	}
+	return def
+}
+
 func getenvBool(key string, def bool) bool {
 	switch strings.ToLower(os.Getenv(key)) {
 	case "1", "true", "yes", "on":
@@ -84,6 +99,10 @@ func main() {
 			mode:         getenv("AUTH_MODE", "local"),
 			user:         os.Getenv("AUTH_USER"),
 			pass:         os.Getenv("AUTH_PASS"),
+			viewerUser:   os.Getenv("AUTH_VIEWER_USER"),
+			viewerPass:   os.Getenv("AUTH_VIEWER_PASS"),
+			adminGroup:   os.Getenv("OIDC_ADMIN_GROUP"),
+			groupsClaim:  os.Getenv("OIDC_GROUPS_CLAIM"),
 			issuer:       os.Getenv("OIDC_ISSUER"),
 			clientID:     os.Getenv("OIDC_CLIENT_ID"),
 			clientSecret: os.Getenv("OIDC_CLIENT_SECRET"),
@@ -95,16 +114,23 @@ func main() {
 		},
 		rdns:       getenvBool("RDNS", true),
 		dnsServer:  os.Getenv("DNS_SERVER"),
-		allowPurge: getenvBool("ALLOW_PURGE", true),
+		allowPurge: getenvBool("ALLOW_PURGE", false),
 		exportMax:  getenvInt("EXPORT_MAX", 100000),
 		dockerLogs: getenvBool("DOCKER_LOGS", false),
 		dockerHost: getenv("DOCKER_HOST", "unix:///var/run/docker.sock"),
 		backfill:   getenvDuration("DOCKER_BACKFILL", time.Hour),
 		hostRoot:   getenv("HOST_LOGS_ROOT", "/host"),
 		hostFill:   getenvDuration("HOST_LOGS_BACKFILL", time.Hour),
+		kmsgDevice: getenv("DMESG_DEVICE", "/dev/kmsg"),
+		kmsgFill:   getenvDuration("DMESG_BACKFILL", time.Hour),
+		auditLog:   getenv("AUDIT_LOG", "/var/log/audit/audit.log"),
+		auditHost:  os.Getenv("AUDIT_HOST"),
+		auditFill:  getenvDuration("AUDIT_BACKFILL", time.Hour),
+		filesFill:  getenvDuration("FILES_BACKFILL", time.Hour),
 		batchSize:  getenvInt("BATCH_SIZE", 1000),
 		queueSize:  getenvInt("QUEUE_SIZE", 100000),
 		flushEvery: time.Duration(getenvInt("FLUSH_MS", 1000)) * time.Millisecond,
+		spoolMax:   int64(getenvIntZero("SPOOL_MAX_MB", 1024)) << 20,
 	}
 
 	cfg.auth.dataDir = cfg.dataDir
@@ -117,10 +143,19 @@ func main() {
 		log.Fatalf("tags: %v", err)
 	}
 
-	store := NewStore(cfg.vlogsURL, cfg.batchSize, cfg.queueSize, cfg.flushEvery)
+	var spool *Spool
+	if cfg.spoolMax > 0 {
+		if spool, err = OpenSpool(filepath.Join(cfg.dataDir, "spool"), cfg.spoolMax); err != nil {
+			log.Printf("disk buffer disabled: %v", err) // before the self-logs exist
+			spool = nil
+		}
+	}
+	store := NewStore(cfg.vlogsURL, cfg.batchSize, cfg.queueSize, cfg.flushEvery, spool)
+	// The store stops after everything else, so the stop event is still stored.
+	storeCtx, stopStore := context.WithCancel(context.Background())
 	storeDone := make(chan struct{})
 	go func() {
-		store.Run(ctx)
+		store.Run(storeCtx)
 		close(storeDone)
 	}()
 
@@ -128,12 +163,33 @@ func main() {
 	rdns := NewReverseDNS(cfg.rdns, cfg.dnsServer)
 	sink := func(e *Entry) {
 		// Host sent as an IP (or no host in the header): replace it with its DNS name.
-		// A new IP waits at most 300 ms; slower lookups finish in the background.
-		if name := rdns.Lookup(e.Host, 300*time.Millisecond); name != "" {
-			e.HostIP, e.Host = e.Host, name
-		}
+		// A new IP waits at most 300 ms, without holding up the listener; slower
+		// lookups finish in the background.
+		rdns.Resolve(e.Host, 300*time.Millisecond, func(name string) {
+			if name != "" {
+				e.HostIP, e.Host = e.Host, name
+			}
+			store.Enqueue(e)
+			hub.Publish(e)
+		})
+	}
+	// Internal events of LogStream (host=logstream), WARNING and above unless
+	// changed in Settings > Sources.
+	selfLog = NewSelfLog(cfg.dataDir, func(e *Entry) {
 		store.Enqueue(e)
 		hub.Publish(e)
+	})
+	selfCtx, stopSelf := context.WithCancel(context.Background())
+	selfDone := make(chan struct{})
+	go func() {
+		selfLog.Run(selfCtx)
+		close(selfDone)
+	}()
+	logEvent("main", 5, "LogStream started")
+
+	tcpMaxConns = getenvInt("SYSLOG_TCP_MAX_CONNS", tcpMaxConns)
+	if d := getenvDuration("SYSLOG_TCP_IDLE", tcpIdle); d > 0 {
+		tcpIdle = d
 	}
 	// Listening errors (port already used…) are shown in Settings > Sources.
 	syslogSrv := NewSyslogServer(ctx, cfg.syslogAddr, getenv("SYSLOG_PUBLIC_PORT", ""), cfg.dataDir, sink)
@@ -143,11 +199,12 @@ func main() {
 		log.Fatal(err)
 	}
 	mux := http.NewServeMux()
-	api := &API{store: store, hub: hub, tags: tags, rdns: rdns, allowPurge: cfg.allowPurge, exportMax: cfg.exportMax, syslog: syslogSrv}
+	presets := getenv("PRESETS_FILE", filepath.Join(cfg.dataDir, "presets.json"))
+	api := &API{store: store, hub: hub, tags: tags, presets: presets, rdns: rdns, allowPurge: cfg.allowPurge, exportMax: cfg.exportMax, syslog: syslogSrv}
 	if cfg.dockerLogs {
 		dm, err := NewDockerManager(cfg.dockerHost, cfg.dataDir, cfg.backfill, sink)
 		if err != nil {
-			log.Printf("docker logs disabled: %v", err)
+			logEvent("docker", 3, "Docker logs disabled: %v", err)
 		} else {
 			go dm.Run(ctx)
 			api.docker = dm
@@ -157,20 +214,39 @@ func main() {
 	// System logs of the host (journal or /var/log), off until enabled in Settings > Sources.
 	api.host = NewHostLogs(cfg.hostRoot, cfg.dataDir, cfg.hostFill, sink)
 	go api.host.Run(ctx)
+	// Kernel messages of the host (/dev/kmsg), off until enabled in Settings > Sources.
+	api.dmesg = NewDmesg(cfg.kmsgDevice, cfg.dataDir, cfg.kmsgFill, sink)
+	go api.dmesg.Run(ctx)
+	// Linux audit log of the host (auditd), off until enabled in Settings > Sources.
+	api.audit = NewAudit(cfg.auditLog, cfg.hostRoot, cfg.auditHost, cfg.dataDir, cfg.auditFill, sink)
+	go api.audit.Run(ctx)
+	// Log files of other programs (Traefik, nginx…) mounted in the container,
+	// declared in Settings > Sources.
+	api.files = NewFiles(cfg.hostRoot, cfg.dataDir, cfg.filesFill, sink)
+	go api.files.Run(ctx)
+	api.selfLog = selfLog
 	api.Routes(mux)
 	mux.Handle("GET /", http.FileServer(http.FS(static)))
 
-	handler, err := newAuth(cfg.auth, mux)
+	handler, err := newAuth(cfg.auth, readOnly(mux))
 	if err != nil {
 		log.Fatalf("auth: %v", err)
 	}
 	if o, ok := handler.(*OIDC); ok {
 		go o.checkProvider()
 	}
+	_, local := handler.(*Local)
+	_, oidc := handler.(*OIDC)
+	authOn := local || oidc
+	if !authOn {
+		log.Printf("warning: no authentication (AUTH_USER is empty): anyone who can reach %s can read the logs and change the settings", cfg.httpAddr)
+	}
+	handler = secure(handler, contentSecurityPolicy(static), authOn)
 	srv := &http.Server{
 		Addr:              cfg.httpAddr,
 		Handler:           handler,
 		ReadHeaderTimeout: 10 * time.Second,
+		IdleTimeout:       2 * time.Minute,
 		// Requests inherit the global context so SSE streams end on shutdown.
 		BaseContext: func(net.Listener) context.Context { return ctx },
 	}
@@ -185,6 +261,10 @@ func main() {
 	if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
 		log.Fatalf("http: %v", err)
 	}
+	logEvent("main", 5, "LogStream stopping")
+	stopSelf()
+	<-selfDone
+	stopStore()
 	<-storeDone
 	log.Println("shutdown complete")
 }

presets.go

@@ -0,0 +1,110 @@
+package main
+
+import (
+	_ "embed"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"os"
+)
+
+// Built-in tag presets, used when no presets file is found (PRESETS_FILE,
+// /data/presets.json by default). See docs/presets.md.
+//
+//go:embed presets.json
+var builtinPresets []byte
+
+// i18nText is a text per language ({"en": "...", "fr": "..."}) or one plain
+// string for every language.
+type i18nText map[string]string
+
+func (t *i18nText) UnmarshalJSON(b []byte) error {
+	var s string
+	if json.Unmarshal(b, &s) == nil {
+		*t = i18nText{"en": s}
+		return nil
+	}
+	var m map[string]string
+	if err := json.Unmarshal(b, &m); err != nil {
+		return errors.New("expected a string or an object of strings per language")
+	}
+	*t = m
+	return nil
+}
+
+type PresetTag struct {
+	Label         i18nText `json:"label,omitempty"`
+	Pattern       string   `json:"pattern"`
+	Color         string   `json:"color"`
+	Regex         *bool    `json:"regex,omitempty"` // regular expression unless false
+	WholeWord     bool     `json:"wholeWord,omitempty"`
+	CaseSensitive bool     `json:"caseSensitive,omitempty"`
+}
+
+type Preset struct {
+	ID   string      `json:"id"`
+	Name i18nText    `json:"name"`
+	Tags []PresetTag `json:"tags"`
+}
+
+type PresetGroup struct {
+	Group   i18nText `json:"group"`
+	Presets []Preset `json:"presets"`
+}
+
+// parsePresets decodes and checks a presets file with the same rules as the
+// tags, so that every preset can be added as is.
+func parsePresets(b []byte) ([]PresetGroup, error) {
+	var groups []PresetGroup
+	if err := json.Unmarshal(b, &groups); err != nil {
+		return nil, err
+	}
+	seen := map[string]bool{}
+	for _, g := range groups {
+		for _, p := range g.Presets {
+			if p.ID == "" || seen[p.ID] {
+				return nil, fmt.Errorf("preset %q: missing or duplicate id", p.ID)
+			}
+			seen[p.ID] = true
+			if len(p.Tags) == 0 {
+				return nil, fmt.Errorf("preset %q: no tags", p.ID)
+			}
+			for i, pt := range p.Tags {
+				t := Tag{Pattern: pt.Pattern, Color: pt.Color, Regex: pt.Regex == nil || *pt.Regex}
+				if err := t.validate(); err != nil {
+					return nil, fmt.Errorf("preset %q, tag %d: %w", p.ID, i+1, err)
+				}
+			}
+		}
+	}
+	return groups, nil
+}
+
+// presetsResponse is what GET /api/presets returns.
+type presetsResponse struct {
+	Source string        `json:"source"` // "file" or "builtin"
+	File   string        `json:"file"`
+	Error  string        `json:"error,omitempty"` // the file is invalid: built-in presets are used
+	Groups []PresetGroup `json:"groups"`
+}
+
+// loadPresets reads the presets file on every call, so that edits apply
+// without a restart, and falls back to the built-in presets.
+func loadPresets(path string) presetsResponse {
+	res := presetsResponse{Source: "builtin", File: path}
+	if path != "" {
+		b, err := os.ReadFile(path)
+		switch {
+		case err == nil:
+			if res.Groups, err = parsePresets(b); err == nil {
+				res.Source = "file"
+				return res
+			}
+			res.Error = err.Error()
+		case !errors.Is(err, os.ErrNotExist):
+			res.Error = err.Error()
+		}
+	}
+	res.Groups, _ = parsePresets(builtinPresets) // checked by the tests
+	return res
+}

presets.json

@@ -0,0 +1,244 @@
+[
+  {
+    "group": "HTTP/HTTPS",
+    "presets": [
+      {
+        "id": "http_status",
+        "name": { "en": "HTTP status codes", "fr": "Codes HTTP" },
+        "tags": [
+          {
+            "label": "HTTP 2xx",
+            "color": "#86efac",
+            "pattern": "(?:\" |\"(?:status|DownstreamStatus|OriginStatus|status_code)\": ?|(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/\\+?\\d+ )(?<hl>2\\d\\d)\\b"
+          },
+          {
+            "label": "HTTP 3xx",
+            "color": "#93c5fd",
+            "pattern": "(?:\" |\"(?:status|DownstreamStatus|OriginStatus|status_code)\": ?|(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/\\+?\\d+ )(?<hl>3\\d\\d)\\b"
+          },
+          {
+            "label": "HTTP 4xx",
+            "color": "#fdba74",
+            "pattern": "(?:\" |\"(?:status|DownstreamStatus|OriginStatus|status_code)\": ?|(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/\\+?\\d+ )(?<hl>4\\d\\d)\\b"
+          },
+          {
+            "label": "HTTP 5xx",
+            "color": "#f87171",
+            "pattern": "(?:\" |\"(?:status|DownstreamStatus|OriginStatus|status_code)\": ?|(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/(?:-1|\\d+)/\\+?\\d+ )(?<hl>5\\d\\d)\\b"
+          }
+        ]
+      },
+      {
+        "id": "http_methods",
+        "name": { "en": "HTTP methods", "fr": "Méthodes HTTP" },
+        "tags": [
+          {
+            "label": "GET/HEAD/OPTIONS",
+            "color": "#cbd5e1",
+            "caseSensitive": true,
+            "pattern": "\"(?<hl>GET|HEAD|OPTIONS)[ \"]"
+          },
+          {
+            "label": "POST/PUT/PATCH",
+            "color": "#c4b5fd",
+            "caseSensitive": true,
+            "pattern": "\"(?<hl>POST|PUT|PATCH)[ \"]"
+          },
+          {
+            "label": "DELETE",
+            "color": "#f9a8d4",
+            "caseSensitive": true,
+            "pattern": "\"(?<hl>DELETE)[ \"]"
+          }
+        ]
+      },
+      {
+        "id": "http_probes",
+        "name": { "en": "Probes and attacks", "fr": "Sondes et attaques" },
+        "tags": [
+          {
+            "label": { "en": "probes / attacks", "fr": "sondes / attaques" },
+            "color": "#fda4af",
+            "pattern": "(?:wp-login\\.php|xmlrpc\\.php|wp-admin|phpmyadmin|/\\.env|/\\.git|/\\.aws|/cgi-bin/|\\.\\./|%2e%2e|/etc/passwd|<script|union(?:\\s|%20|\\+)+select)"
+          }
+        ]
+      },
+      {
+        "id": "http_bots",
+        "name": { "en": "Bots and scripts", "fr": "Robots et scripts" },
+        "tags": [
+          {
+            "label": { "en": "bots / scripts", "fr": "robots / scripts" },
+            "color": "#fde68a",
+            "pattern": "\\b(?:[a-z]*bot|crawler|spider|curl|wget|python-requests|Go-http-client|zgrab|masscan|nmap|sqlmap|nikto)\\b"
+          }
+        ]
+      },
+      {
+        "id": "http_errors",
+        "name": { "en": "TLS/HTTPS and proxy errors", "fr": "Erreurs TLS/HTTPS et proxy" },
+        "tags": [
+          {
+            "label": { "en": "TLS errors", "fr": "erreurs TLS" },
+            "color": "#f0abfc",
+            "pattern": "(?:TLS handshake error|SSL_do_handshake\\(\\) failed|SSL handshake|SSL routines|certificate (?:has )?expired|certificate verify failed|bad certificate|unknown certificate|x509:)"
+          },
+          {
+            "label": { "en": "proxy errors", "fr": "erreurs proxy" },
+            "color": "#fdba74",
+            "pattern": "(?:upstream timed out|upstream prematurely closed|no live upstreams|connect\\(\\) failed|connection refused|bad gateway|gateway time-?out|service unavailable)"
+          }
+        ]
+      }
+    ]
+  },
+  {
+    "group": { "en": "System", "fr": "Système" },
+    "presets": [
+      {
+        "id": "sys_auth",
+        "name": { "en": "SSH and logins", "fr": "SSH et connexions" },
+        "tags": [
+          {
+            "label": { "en": "login failures", "fr": "échecs de connexion" },
+            "color": "#fca5a5",
+            "pattern": "(?:Failed (?:password|publickey|none)|Invalid user|authentication failures?|Connection closed by (?:invalid|authenticating) user|maximum authentication attempts exceeded|FAILED (?:LOGIN|SU)|incorrect password attempts?|NOT in sudoers)"
+          },
+          {
+            "label": { "en": "logins", "fr": "connexions" },
+            "color": "#86efac",
+            "pattern": "(?:Accepted (?:password|publickey|keyboard-interactive(?:/pam)?)|session opened for user|New session \\S+ of user)"
+          }
+        ]
+      },
+      {
+        "id": "sys_sudo",
+        "name": { "en": "sudo commands", "fr": "Commandes sudo" },
+        "tags": [
+          {
+            "label": { "en": "sudo commands", "fr": "commandes sudo" },
+            "color": "#fde68a",
+            "caseSensitive": true,
+            "pattern": "\\bCOMMAND=\\S+"
+          }
+        ]
+      },
+      {
+        "id": "sys_kernel",
+        "name": { "en": "Kernel: OOM, crashes, disks", "fr": "Noyau : OOM, plantages, disques" },
+        "tags": [
+          {
+            "label": { "en": "out of memory", "fr": "mémoire épuisée" },
+            "color": "#f87171",
+            "pattern": "(?:Out of memory|oom-kill(?:er)?|oom_reaper|Killed process \\d+|invoked oom-killer)"
+          },
+          {
+            "label": { "en": "kernel errors", "fr": "erreurs noyau" },
+            "color": "#fda4af",
+            "pattern": "(?:Kernel panic|\\bBUG: |\\bOops\\b|Call Trace|segfault at|general protection fault|I/O error|EXT4-fs error|Buffer I/O error|blocked for more than \\d+ seconds|Hardware Error|soft lockup|hard LOCKUP)"
+          }
+        ]
+      },
+      {
+        "id": "sys_systemd",
+        "name": { "en": "systemd services", "fr": "Services systemd" },
+        "tags": [
+          {
+            "label": { "en": "failed services", "fr": "services en échec" },
+            "color": "#fca5a5",
+            "pattern": "(?:Failed to start|failed with result|Main process exited, code=(?:exited|killed|dumped)|entered failed state|Start request repeated too quickly|Dependency failed)"
+          },
+          {
+            "label": { "en": "service start/stop", "fr": "démarrage/arrêt de service" },
+            "color": "#bbf7d0",
+            "caseSensitive": true,
+            "pattern": "\\b(?:Started|Starting|Stopped|Stopping|Reloaded|Reloading|Reached target)\\b"
+          }
+        ]
+      },
+      {
+        "id": "sys_firewall",
+        "name": { "en": "Firewall and fail2ban", "fr": "Pare-feu et fail2ban" },
+        "tags": [
+          {
+            "label": { "en": "firewall", "fr": "pare-feu" },
+            "color": "#fdba74",
+            "caseSensitive": true,
+            "pattern": "(?:\\[UFW (?:BLOCK|ALLOW|AUDIT|LIMIT BLOCK)\\]|\\b(?:DROP|REJECT)\\b|\\b(?:Ban|Unban|Found) \\d{1,3}(?:\\.\\d{1,3}){3}\\b)"
+          }
+        ]
+      }
+    ]
+  },
+  {
+    "group": "Applications",
+    "presets": [
+      {
+        "id": "app_docker",
+        "name": { "en": "Docker and containers", "fr": "Docker et conteneurs" },
+        "tags": [
+          {
+            "label": { "en": "container problems", "fr": "problèmes de conteneur" },
+            "color": "#fcd34d",
+            "pattern": "(?:\\bOOMKilled\\b|exited with code [1-9]\\d*|exit code: [1-9]\\d*|health_status: unhealthy|\\bunhealthy\\b|Back-off restarting|CrashLoopBackOff|container (?:die|kill|oom)\\b|restarting \\(\\d+\\))"
+          }
+        ]
+      },
+      {
+        "id": "app_db",
+        "name": { "en": "Databases", "fr": "Bases de données" },
+        "tags": [
+          {
+            "label": { "en": "database errors", "fr": "erreurs base de données" },
+            "color": "#c4b5fd",
+            "pattern": "(?:\\bdeadlock(?: detected| found)?\\b|duplicate key|too many (?:connections|clients)|lock wait timeout|slow query|could not connect to server|server has gone away|out of shared memory|terminating connection|Access denied for user|password authentication failed)"
+          }
+        ]
+      }
+    ]
+  },
+  {
+    "group": { "en": "General", "fr": "Général" },
+    "presets": [
+      {
+        "id": "gen_levels",
+        "name": { "en": "Log levels", "fr": "Niveaux de log" },
+        "tags": [
+          {
+            "label": { "en": "fatal / critical", "fr": "fatal / critique" },
+            "color": "#ef4444",
+            "pattern": "\\b(?:fatal|crit(?:ical)?|panic|emerg(?:ency)?)\\b"
+          },
+          {
+            "label": "info / notice",
+            "color": "#bfdbfe",
+            "pattern": "\\b(?:info|notice)\\b"
+          },
+          {
+            "label": "debug / trace",
+            "color": "#e5e7eb",
+            "pattern": "\\b(?:debug|trace)\\b"
+          },
+          {
+            "label": "ok",
+            "color": "#86efac",
+            "regex": false,
+            "wholeWord": true,
+            "pattern": "ok"
+          }
+        ]
+      },
+      {
+        "id": "gen_ip",
+        "name": { "en": "IPv4 addresses", "fr": "Adresses IPv4" },
+        "tags": [
+          {
+            "label": { "en": "IPv4 addresses", "fr": "adresses IPv4" },
+            "color": "#a5f3fc",
+            "pattern": "\\b(?:(?:25[0-5]|2[0-4]\\d|1?\\d?\\d)\\.){3}(?:25[0-5]|2[0-4]\\d|1?\\d?\\d)\\b"
+          }
+        ]
+      }
+    ]
+  }
+]

presets_test.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestBuiltinPresets(t *testing.T) {
+	groups, err := parsePresets(builtinPresets)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(groups) == 0 {
+		t.Fatal("no built-in presets")
+	}
+}
+
+func TestLoadPresetsFile(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "presets.json")
+
+	if res := loadPresets(path); res.Source != "builtin" || res.Error != "" {
+		t.Fatalf("missing file: got %q, error %q", res.Source, res.Error)
+	}
+
+	os.WriteFile(path, []byte(`[{"group":"Mine","presets":[{"id":"a","name":{"en":"A","fr":"A fr"},
+		"tags":[{"label":"x","pattern":"foo|bar","color":"#112233"},{"pattern":"a.b","color":"#445566","regex":false}]}]}]`), 0o644)
+	res := loadPresets(path)
+	if res.Source != "file" || res.Error != "" || res.Groups[0].Presets[0].Name["fr"] != "A fr" || res.Groups[0].Group["en"] != "Mine" {
+		t.Fatalf("valid file: %+v", res)
+	}
+
+	for _, bad := range []string{
+		`not json`,
+		`[{"group":"G","presets":[{"id":"a","name":"A","tags":[{"pattern":"(","color":"#112233"}]}]}]`,
+		`[{"group":"G","presets":[{"id":"a","name":"A","tags":[{"pattern":"x","color":"red"}]}]}]`,
+		`[{"group":"G","presets":[{"id":"a","name":"A","tags":[]}]}]`,
+		`[{"group":"G","presets":[{"id":"a","name":"A","tags":[{"pattern":"x","color":"#112233"}]},{"id":"a","name":"B","tags":[{"pattern":"y","color":"#112233"}]}]}]`,
+	} {
+		os.WriteFile(path, []byte(bad), 0o644)
+		if res := loadPresets(path); res.Source != "builtin" || res.Error == "" || len(res.Groups) == 0 {
+			t.Errorf("%s: got %q, error %q", bad, res.Source, res.Error)
+		}
+	}
+}

query.go

@@ -119,10 +119,10 @@ func (f Filter) filterExpr() string {
 		parts = append(parts, "app:="+strconv.Quote(f.App))
 	}
 	switch f.Source {
-	case "docker", "host":
+	case "docker", "host", "kernel", "audit", "logstream", "file":
 		parts = append(parts, `source_type:=`+strconv.Quote(f.Source))
 	case "syslog": // also matches logs stored before source_type existed
-		parts = append(parts, `!(source_type:in("docker","host"))`)
+		parts = append(parts, `!(source_type:in("docker","host","kernel","audit","logstream","file"))`)
 	}
 	if f.Severity >= 0 && f.Severity < 7 {
 		names := make([]string, 0, 8)

rdns.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"container/list"
 	"context"
 	"net"
 	"strings"
@@ -15,17 +16,26 @@ type ReverseDNS struct {
 	posTTL  time.Duration // cache duration of a found name
 	negTTL  time.Duration // cache duration of "no name"
 
+	lookups chan struct{} // limits the lookups running at once
+	waiters chan struct{} // limits the messages waiting for a lookup (Resolve)
+
 	mu    sync.Mutex
-	cache map[string]*rdnsEntry
+	cache map[string]*list.Element // ip -> element of lru
+	lru   *list.List               // *rdnsEntry, most recently used first
 }
 
 type rdnsEntry struct {
+	ip      string
 	name    string
 	expires time.Time
 	done    chan struct{} // closed once the lookup has finished
 }
 
-const rdnsMaxEntries = 10000
+const (
+	rdnsMaxEntries = 10000
+	rdnsMaxLookups = 64
+	rdnsMaxWaiters = 1024
+)
 
 // NewReverseDNS uses the system resolver, or `server` ("ip" or "ip:port") when set.
 func NewReverseDNS(enabled bool, server string) *ReverseDNS {
@@ -47,7 +57,10 @@ func NewReverseDNS(enabled bool, server string) *ReverseDNS {
 		r:       r,
 		posTTL:  time.Hour,
 		negTTL:  10 * time.Minute,
-		cache:   make(map[string]*rdnsEntry),
+		lookups: make(chan struct{}, rdnsMaxLookups),
+		waiters: make(chan struct{}, rdnsMaxWaiters),
+		cache:   make(map[string]*list.Element),
+		lru:     list.New(),
 	}
 }
 
@@ -60,6 +73,38 @@ func isClosed(ch chan struct{}) bool {
 	}
 }
 
+// entry returns the cache entry of ip, starting its lookup when it is missing
+// or expired, or nil when too many lookups are already running (a flood of
+// unknown addresses). The least recently used entry makes room for a new one.
+func (d *ReverseDNS) entry(ip string) *rdnsEntry {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+	if el := d.cache[ip]; el != nil {
+		e := el.Value.(*rdnsEntry)
+		if !isClosed(e.done) || time.Now().Before(e.expires) {
+			d.lru.MoveToFront(el)
+			return e
+		}
+	}
+	select {
+	case d.lookups <- struct{}{}:
+	default:
+		return nil
+	}
+	if el := d.cache[ip]; el != nil {
+		d.lru.Remove(el)
+	}
+	for d.lru.Len() >= rdnsMaxEntries {
+		old := d.lru.Back()
+		d.lru.Remove(old)
+		delete(d.cache, old.Value.(*rdnsEntry).ip)
+	}
+	e := &rdnsEntry{ip: ip, done: make(chan struct{})}
+	d.cache[ip] = d.lru.PushFront(e)
+	go d.resolve(ip, e)
+	return e
+}
+
 // Lookup returns the name of ip, or "" when ip is not an IP address, has no
 // PTR record, or is not resolved within `wait`. A lookup that takes longer
 // keeps running in the background and fills the cache for later calls.
@@ -67,18 +112,10 @@ func (d *ReverseDNS) Lookup(ip string, wait time.Duration) string {
 	if !d.enabled || net.ParseIP(ip) == nil {
 		return ""
 	}
-	d.mu.Lock()
-	e := d.cache[ip]
-	if e == nil || (isClosed(e.done) && time.Now().After(e.expires)) {
-		if len(d.cache) >= rdnsMaxEntries {
-			d.cache = make(map[string]*rdnsEntry)
-		}
-		e = &rdnsEntry{done: make(chan struct{})}
-		d.cache[ip] = e
-		go d.resolve(ip, e)
+	e := d.entry(ip)
+	if e == nil {
+		return ""
 	}
-	d.mu.Unlock()
-
 	if !isClosed(e.done) {
 		timer := time.NewTimer(wait)
 		defer timer.Stop()
@@ -91,6 +128,43 @@ func (d *ReverseDNS) Lookup(ip string, wait time.Duration) string {
 	return e.name
 }
 
+// Resolve is Lookup without blocking the caller: fn gets the name (or "") at
+// once when it is known, otherwise from a goroutine after at most `wait`. The
+// syslog listeners use it so that a slow DNS server never delays the reading
+// of the next messages.
+func (d *ReverseDNS) Resolve(ip string, wait time.Duration, fn func(name string)) {
+	if !d.enabled || net.ParseIP(ip) == nil {
+		fn("")
+		return
+	}
+	e := d.entry(ip)
+	switch {
+	case e == nil:
+		fn("")
+		return
+	case isClosed(e.done):
+		fn(e.name)
+		return
+	}
+	select {
+	case d.waiters <- struct{}{}:
+	default:
+		fn("") // too many messages waiting already
+		return
+	}
+	go func() {
+		defer func() { <-d.waiters }()
+		timer := time.NewTimer(wait)
+		defer timer.Stop()
+		select {
+		case <-e.done:
+			fn(e.name)
+		case <-timer.C:
+			fn("")
+		}
+	}()
+}
+
 // LookupMany resolves several addresses in parallel; unresolved ones are absent.
 func (d *ReverseDNS) LookupMany(ips []string, wait time.Duration) map[string]string {
 	out := make(map[string]string)
@@ -112,6 +186,7 @@ func (d *ReverseDNS) LookupMany(ips []string, wait time.Duration) map[string]str
 }
 
 func (d *ReverseDNS) resolve(ip string, e *rdnsEntry) {
+	defer func() { <-d.lookups }()
 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
 	defer cancel()
 	ttl := d.negTTL

rdns_test.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"net"
+	"testing"
+	"time"
+)
+
+// slowDNS never answers before the context ends.
+func slowDNS() *ReverseDNS {
+	d := NewReverseDNS(true, "")
+	d.r = &net.Resolver{PreferGo: true, Dial: func(ctx context.Context, _, _ string) (net.Conn, error) {
+		<-ctx.Done()
+		return nil, errors.New("timeout")
+	}}
+	return d
+}
+
+func TestResolveDoesNotBlock(t *testing.T) {
+	d := slowDNS()
+	got := make(chan string, 1)
+	start := time.Now()
+	d.Resolve("192.0.2.1", 50*time.Millisecond, func(name string) { got <- name })
+	if time.Since(start) > 20*time.Millisecond {
+		t.Fatal("Resolve waited for the DNS server")
+	}
+	if name := <-got; name != "" {
+		t.Errorf("name %q, want none", name)
+	}
+
+	// Not an IP address: the callback runs at once.
+	called := false
+	d.Resolve("router", time.Second, func(name string) { called = name == "" })
+	if !called {
+		t.Error("callback not called synchronously for a host name")
+	}
+}
+
+func TestReverseDNSLimits(t *testing.T) {
+	d := slowDNS()
+	// Lookups beyond the limit are not started (and not cached).
+	for i := 0; i < rdnsMaxLookups+10; i++ {
+		d.Lookup(net.IPv4(10, 0, byte(i>>8), byte(i)).String(), 0)
+	}
+	if n := d.lru.Len(); n != rdnsMaxLookups {
+		t.Errorf("%d entries, want %d", n, rdnsMaxLookups)
+	}
+}
+
+func TestReverseDNSEvictsLeastRecentlyUsed(t *testing.T) {
+	d := slowDNS()
+	done := make(chan struct{})
+	close(done)
+	add := func(ip string) {
+		e := &rdnsEntry{ip: ip, name: ip + ".lan", expires: time.Now().Add(time.Hour), done: done}
+		d.cache[ip] = d.lru.PushFront(e)
+	}
+	for i := 0; i < rdnsMaxEntries; i++ {
+		add(net.IPv4(10, 1, byte(i>>8), byte(i)).String())
+	}
+	first := net.IPv4(10, 1, 0, 0).String()
+	if name := d.Lookup(first, 0); name != first+".lan" { // now the most recent
+		t.Fatalf("cached name %q", name)
+	}
+	d.entry("192.0.2.9")
+	if d.lru.Len() != rdnsMaxEntries {
+		t.Errorf("%d entries, want %d", d.lru.Len(), rdnsMaxEntries)
+	}
+	if d.cache[first] == nil {
+		t.Error("recently used entry evicted")
+	}
+	if d.cache[net.IPv4(10, 1, 0, 1).String()] != nil {
+		t.Error("least recently used entry kept")
+	}
+}

selflog.go

@@ -0,0 +1,187 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"os"
+	"path/filepath"
+	"sync"
+	"time"
+)
+
+// selfLogConfig is saved in /data/selflog.json and edited in Settings > Sources.
+type selfLogConfig struct {
+	Enabled  bool   `json:"enabled"`
+	MinLevel string `json:"min_level"` // severity name: "err", "warning", "notice", "info"…
+}
+
+// SelfLog turns the internal events of LogStream (storage errors, listener
+// failures, sources that stop…) into log entries, with host=logstream and
+// app=component. Events go through a bounded queue and a per-message
+// throttle: an event about a failing Store is itself stored through that
+// Store, so it must never be able to loop or pile up.
+type SelfLog struct {
+	cfgPath  string
+	sink     func(*Entry)
+	queue    chan *Entry
+	interval time.Duration // one event per component and message format per interval
+
+	mu         sync.Mutex
+	cfg        selfLogConfig
+	last       map[string]time.Time
+	suppressed map[string]int
+	emitted    uint64
+	dropped    uint64
+	throttled  uint64
+}
+
+// selfLog receives the events of logEvent; nil (tests) only writes them to
+// the process log.
+var selfLog *SelfLog
+
+func NewSelfLog(dataDir string, sink func(*Entry)) *SelfLog {
+	s := &SelfLog{
+		cfgPath:    filepath.Join(dataDir, "selflog.json"),
+		sink:       sink,
+		queue:      make(chan *Entry, 256),
+		interval:   30 * time.Second,
+		cfg:        selfLogConfig{Enabled: true, MinLevel: "warning"},
+		last:       map[string]time.Time{},
+		suppressed: map[string]int{},
+	}
+	if b, err := os.ReadFile(s.cfgPath); err == nil {
+		var cfg selfLogConfig
+		if json.Unmarshal(b, &cfg) == nil {
+			s.cfg = normSelfLogConfig(cfg)
+		}
+	}
+	return s
+}
+
+func normSelfLogConfig(cfg selfLogConfig) selfLogConfig {
+	if sevNum(cfg.MinLevel) < 0 {
+		cfg.MinLevel = "warning"
+	}
+	return cfg
+}
+
+func sevNum(name string) int {
+	for i, n := range severityNames {
+		if n == name {
+			return i
+		}
+	}
+	return -1
+}
+
+// logEvent writes an internal event to the process log and, when the
+// self-logs source is on and the level is high enough, emits it as an entry.
+// sev is a syslog severity (3 err, 4 warning, 5 notice, 6 info).
+func logEvent(component string, sev int, format string, args ...any) {
+	msg := fmt.Sprintf(format, args...)
+	log.Printf("%s: %s", component, msg)
+	if s := selfLog; s != nil {
+		s.Emit(component, sev, format, msg, time.Now())
+	}
+}
+
+// Emit queues an event without ever blocking. The same component and message
+// format are let through once per interval; the next one says how many were
+// left out in between.
+func (s *SelfLog) Emit(component string, sev int, format, msg string, now time.Time) {
+	sev = min(max(sev, 0), 7)
+	key := component + "\x00" + format
+	s.mu.Lock()
+	if !s.cfg.Enabled || sev > sevNum(s.cfg.MinLevel) {
+		s.mu.Unlock()
+		return
+	}
+	if t, ok := s.last[key]; ok && now.Sub(t) < s.interval {
+		s.suppressed[key]++
+		s.throttled++
+		s.mu.Unlock()
+		return
+	}
+	s.last[key] = now
+	if n := s.suppressed[key]; n > 0 {
+		msg += fmt.Sprintf(" (%d similar events not shown)", n)
+		delete(s.suppressed, key)
+	}
+	if len(s.last) > 1000 { // formats are constants: only a bug could get here
+		clear(s.last)
+	}
+	s.mu.Unlock()
+
+	e := &Entry{
+		Time:       now,
+		Received:   now,
+		Host:       "logstream",
+		App:        component,
+		Facility:   "syslog",
+		Severity:   severityNames[sev],
+		SevNum:     sev,
+		Message:    msg,
+		Proto:      "internal",
+		SourceType: "logstream",
+		// Wait stays false: when the Store queue is full, the event is dropped
+		// instead of blocking the component that reports it.
+	}
+	select {
+	case s.queue <- e:
+	default:
+		s.mu.Lock()
+		s.dropped++
+		s.mu.Unlock()
+	}
+}
+
+// Run hands the queued events to the sink until the context ends, then
+// delivers what is left (the stop event among them).
+func (s *SelfLog) Run(ctx context.Context) {
+	for {
+		select {
+		case e := <-s.queue:
+			s.deliver(e)
+		case <-ctx.Done():
+			for {
+				select {
+				case e := <-s.queue:
+					s.deliver(e)
+				default:
+					return
+				}
+			}
+		}
+	}
+}
+
+func (s *SelfLog) deliver(e *Entry) {
+	s.sink(e)
+	s.mu.Lock()
+	s.emitted++
+	s.mu.Unlock()
+}
+
+// Configure saves and applies the configuration.
+func (s *SelfLog) Configure(cfg selfLogConfig) error {
+	cfg = normSelfLogConfig(cfg)
+	s.mu.Lock()
+	s.cfg = cfg
+	s.mu.Unlock()
+	return writeJSONFile(s.cfgPath, cfg)
+}
+
+// Status is the state shown in Settings > Sources.
+func (s *SelfLog) Status() map[string]any {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return map[string]any{
+		"enabled":   s.cfg.Enabled,
+		"min_level": s.cfg.MinLevel,
+		"emitted":   s.emitted,
+		"dropped":   s.dropped,
+		"throttled": s.throttled,
+	}
+}

selflog_test.go

@@ -0,0 +1,102 @@
+package main
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestSelfLogEmit(t *testing.T) {
+	now := time.Unix(1759572000, 0)
+	tests := []struct {
+		name   string
+		cfg    selfLogConfig
+		events []int // severities, one second apart, same message format
+		want   int   // entries queued
+		suffix string
+	}{
+		{"warning and above", selfLogConfig{Enabled: true, MinLevel: "warning"}, []int{3}, 1, ""},
+		{"below the level", selfLogConfig{Enabled: true, MinLevel: "warning"}, []int{5, 6}, 0, ""},
+		{"info level", selfLogConfig{Enabled: true, MinLevel: "info"}, []int{6}, 1, ""},
+		{"disabled", selfLogConfig{Enabled: false, MinLevel: "debug"}, []int{0}, 0, ""},
+		{"bad level falls back to warning", normSelfLogConfig(selfLogConfig{Enabled: true, MinLevel: "loud"}), []int{4, 5}, 1, ""},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := NewSelfLog(t.TempDir(), func(*Entry) {})
+			s.cfg = tt.cfg
+			for i, sev := range tt.events {
+				s.Emit("store", sev, "fmt %d", "msg", now.Add(time.Duration(i)*time.Second))
+			}
+			if len(s.queue) != tt.want {
+				t.Fatalf("%d queued, want %d", len(s.queue), tt.want)
+			}
+		})
+	}
+
+	// Same component and format: once per interval, then a count of the others.
+	s := NewSelfLog(t.TempDir(), func(*Entry) {})
+	for i := 0; i < 5; i++ {
+		s.Emit("store", 3, "%d messages lost", "x", now.Add(time.Duration(i)*time.Second))
+	}
+	s.Emit("syslog", 3, "%d messages lost", "y", now) // another component
+	s.Emit("store", 3, "%d messages lost", "z", now.Add(s.interval))
+	if len(s.queue) != 3 {
+		t.Fatalf("%d queued", len(s.queue))
+	}
+	<-s.queue
+	if e := <-s.queue; e.App != "syslog" || e.Host != "logstream" || e.SourceType != "logstream" || e.Wait {
+		t.Fatalf("entry %+v", e)
+	}
+	if e := <-s.queue; e.Message != "z (4 similar events not shown)" || e.Severity != "err" {
+		t.Fatalf("message %q", e.Message)
+	}
+	if st := s.Status(); st["throttled"] != uint64(4) {
+		t.Fatalf("status %v", st)
+	}
+
+	// A full queue drops events instead of blocking.
+	s = NewSelfLog(t.TempDir(), func(*Entry) {})
+	for i := 0; i < cap(s.queue)+10; i++ {
+		s.Emit("store", 3, "event %d", "x", now.Add(time.Duration(i)*s.interval))
+	}
+	if st := s.Status(); st["dropped"] != uint64(10) {
+		t.Fatalf("status %v", st)
+	}
+}
+
+func TestSelfLogRunAndConfigure(t *testing.T) {
+	dir := t.TempDir()
+	sink := &entrySink{}
+	s := NewSelfLog(dir, sink.add)
+	if err := s.Configure(selfLogConfig{Enabled: true, MinLevel: "notice"}); err != nil {
+		t.Fatal(err)
+	}
+	if b, _ := os.ReadFile(filepath.Join(dir, "selflog.json")); !strings.Contains(string(b), `"notice"`) {
+		t.Fatalf("saved %s", b)
+	}
+	if s2 := NewSelfLog(dir, nil); s2.cfg.MinLevel != "notice" {
+		t.Fatalf("reloaded %+v", s2.cfg)
+	}
+	old := selfLog
+	selfLog = s
+	defer func() { selfLog = old }()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+	go func() { s.Run(ctx); close(done) }()
+	logEvent("main", 5, "LogStream started")
+	logEvent("main", 6, "too verbose")
+	cancel()
+	<-done
+	logEvent("main", 5, "LogStream stopping") // queued after Run: not lost if Run drains it
+	sink.mu.Lock()
+	n := len(sink.es)
+	sink.mu.Unlock()
+	if n != 1 || s.Status()["emitted"] != uint64(1) {
+		t.Fatalf("%d entries, status %v", n, s.Status())
+	}
+}

spool.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// Spool keeps on disk the batches VictoriaLogs could not take, so that they
+// are sent later instead of being lost. Each batch is one NDJSON file named
+// <unix nanoseconds>-<lines>.ndjson; files are sent back oldest first.
+type Spool struct {
+	dir string
+	max int64 // maximum total size in bytes
+
+	mu    sync.Mutex
+	size  int64 // bytes on disk
+	lines int64 // messages on disk
+	seq   int64
+}
+
+// errSpoolFull is returned when a batch does not fit within SPOOL_MAX_MB.
+var errSpoolFull = fmt.Errorf("disk buffer full")
+
+// OpenSpool creates the directory if needed and counts the batches already
+// there (left by a previous run).
+func OpenSpool(dir string, max int64) (*Spool, error) {
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return nil, err
+	}
+	s := &Spool{dir: dir, max: max}
+	files, err := s.files()
+	if err != nil {
+		return nil, err
+	}
+	for _, f := range files {
+		s.size += f.size
+		s.lines += f.lines
+	}
+	return s, nil
+}
+
+type spoolFile struct {
+	path  string
+	size  int64
+	lines int64
+}
+
+// files lists the batches on disk, oldest first. Unfinished writes (.tmp)
+// are removed.
+func (s *Spool) files() ([]spoolFile, error) {
+	entries, err := os.ReadDir(s.dir)
+	if err != nil {
+		return nil, err
+	}
+	var out []spoolFile
+	for _, e := range entries {
+		name := e.Name()
+		if strings.HasSuffix(name, ".tmp") {
+			_ = os.Remove(filepath.Join(s.dir, name))
+			continue
+		}
+		base, ok := strings.CutSuffix(name, ".ndjson")
+		if !ok {
+			continue
+		}
+		_, n, _ := strings.Cut(base, "-")
+		lines, _ := strconv.ParseInt(n, 10, 64)
+		info, err := e.Info()
+		if err != nil {
+			continue
+		}
+		out = append(out, spoolFile{path: filepath.Join(s.dir, name), size: info.Size(), lines: lines})
+	}
+	// The names start with a fixed-width timestamp: string order is time order.
+	sort.Slice(out, func(i, j int) bool { return out[i].path < out[j].path })
+	return out, nil
+}
+
+// Write saves one batch of `lines` messages.
+func (s *Spool) Write(body []byte, lines int) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.size+int64(len(body)) > s.max {
+		return errSpoolFull
+	}
+	s.seq++
+	name := fmt.Sprintf("%020d%04d-%d.ndjson", time.Now().UnixNano(), s.seq%10000, lines)
+	path := filepath.Join(s.dir, name)
+	tmp := path + ".tmp"
+	if err := os.WriteFile(tmp, body, 0o644); err != nil {
+		_ = os.Remove(tmp)
+		return err
+	}
+	if err := os.Rename(tmp, path); err != nil {
+		_ = os.Remove(tmp)
+		return err
+	}
+	s.size += int64(len(body))
+	s.lines += int64(lines)
+	return nil
+}
+
+// Oldest returns the oldest batch, or ok=false when the spool is empty.
+func (s *Spool) Oldest() (f spoolFile, body []byte, ok bool, err error) {
+	files, err := s.files()
+	if err != nil || len(files) == 0 {
+		return f, nil, false, err
+	}
+	f = files[0]
+	body, err = os.ReadFile(f.path)
+	return f, body, err == nil, err
+}
+
+// Remove deletes a batch once VictoriaLogs has taken it.
+func (s *Spool) Remove(f spoolFile) {
+	if err := os.Remove(f.path); err != nil && !os.IsNotExist(err) {
+		return
+	}
+	s.mu.Lock()
+	s.size -= f.size
+	s.lines -= f.lines
+	s.mu.Unlock()
+}
+
+// Pending returns the number of messages and bytes waiting on disk.
+func (s *Spool) Pending() (lines, size int64) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	return s.lines, s.size
+}

store.go

@@ -8,7 +8,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"log"
 	"net/http"
 	"net/url"
 	"strings"
@@ -17,43 +16,62 @@ import (
 )
 
 // Store sends messages to VictoriaLogs in batches and queries it with LogsQL.
+// Batches VictoriaLogs cannot take go to the disk spool (when enabled) and
+// are sent again, oldest first, once it answers.
 type Store struct {
 	base         string
 	client       *http.Client
 	streamClient *http.Client
-	in         chan *Entry
-	batchSize  int
-	flushEvery time.Duration
+	in           chan *Entry
+	quit         chan struct{} // closed on shutdown: unblocks waiting producers
+	batchSize    int
+	flushEvery   time.Duration
+	spool        *Spool        // nil: no disk buffer
+	spooled      chan struct{} // wakes the replay loop up after a write to the spool
 
 	received atomic.Int64
 	ingested atomic.Int64
 	dropped  atomic.Int64
 	lastErr  atomic.Value // string
+	failing  atomic.Bool  // VictoriaLogs refused or missed the last send
 }
 
-func NewStore(base string, batchSize, queueSize int, flushEvery time.Duration) *Store {
+func NewStore(base string, batchSize, queueSize int, flushEvery time.Duration, spool *Spool) *Store {
 	s := &Store{
-		base:       strings.TrimRight(base, "/"),
-		client:     &http.Client{Timeout: 60 * time.Second},
+		base:   strings.TrimRight(base, "/"),
+		client: &http.Client{Timeout: 60 * time.Second},
 		// No global timeout: a large export can take longer than a minute. The
 		// request context still cancels it when the browser goes away.
 		streamClient: &http.Client{},
-		in:         make(chan *Entry, queueSize),
-		batchSize:  batchSize,
-		flushEvery: flushEvery,
+		in:           make(chan *Entry, queueSize),
+		quit:         make(chan struct{}),
+		batchSize:    batchSize,
+		flushEvery:   flushEvery,
+		spool:        spool,
+		spooled:      make(chan struct{}, 1),
 	}
 	s.lastErr.Store("")
 	return s
 }
 
-// Enqueue never blocks: when the queue is full, the message is counted as dropped.
+// Enqueue adds a message to the queue. When the queue is full, a message
+// whose producer can wait (Entry.Wait: Docker, host logs) blocks until there
+// is room; any other one (syslog) is counted as dropped.
 func (s *Store) Enqueue(e *Entry) {
 	s.received.Add(1)
 	select {
 	case s.in <- e:
+		return
 	default:
-		s.dropped.Add(1)
 	}
+	if e.Wait {
+		select {
+		case s.in <- e:
+			return
+		case <-s.quit:
+		}
+	}
+	s.dropped.Add(1)
 }
 
 // Run drains the queue into VictoriaLogs until the context is cancelled,
@@ -62,20 +80,16 @@ func (s *Store) Run(ctx context.Context) {
 	ticker := time.NewTicker(s.flushEvery)
 	defer ticker.Stop()
 	batch := make([]*Entry, 0, s.batchSize)
+	if s.spool != nil {
+		go s.replay(ctx)
+	}
 
-	flush := func() {
-		if len(batch) == 0 {
-			return
+	flush := func(ctx context.Context) {
+		if len(batch) > 0 {
+			s.store(ctx, batch)
+			clear(batch)
+			batch = batch[:0]
 		}
-		if err := s.insert(batch); err != nil {
-			s.dropped.Add(int64(len(batch)))
-			s.lastErr.Store(err.Error())
-			log.Printf("victorialogs: %d messages dropped: %v", len(batch), err)
-		} else {
-			s.ingested.Add(int64(len(batch)))
-			s.lastErr.Store("")
-		}
-		batch = batch[:0]
 	}
 
 	for {
@@ -83,20 +97,24 @@ func (s *Store) Run(ctx context.Context) {
 		case e := <-s.in:
 			batch = append(batch, e)
 			if len(batch) >= s.batchSize {
-				flush()
+				flush(ctx)
 			}
 		case <-ticker.C:
-			flush()
+			flush(ctx)
 		case <-ctx.Done():
+			close(s.quit)
+			// The last batches get one short attempt, then go to the spool.
+			end, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
 			for {
 				select {
 				case e := <-s.in:
 					batch = append(batch, e)
 					if len(batch) >= s.batchSize {
-						flush()
+						flush(end)
 					}
 				default:
-					flush()
+					flush(end)
 					return
 				}
 			}
@@ -104,38 +122,179 @@ func (s *Store) Run(ctx context.Context) {
 	}
 }
 
-func (s *Store) insert(batch []*Entry) error {
+// store sends one batch to VictoriaLogs, or to the spool when VictoriaLogs
+// fails or older batches are still waiting there (to keep their order).
+// Entry.Done is called once the batch is stored or spooled.
+func (s *Store) store(ctx context.Context, batch []*Entry) {
+	body, err := encodeBatch(batch)
+	if err == nil {
+		err = s.save(ctx, body, len(batch))
+	}
+	if err != nil {
+		s.dropped.Add(int64(len(batch)))
+		s.lastErr.Store(err.Error())
+		logEvent("store", 3, "%d messages lost: %v", len(batch), err)
+		return
+	}
+	for _, e := range batch {
+		if e.Done != nil {
+			e.Done()
+		}
+	}
+}
+
+func (s *Store) save(ctx context.Context, body []byte, lines int) error {
+	if s.spool == nil {
+		// No disk buffer: retry a few times, then give up.
+		var err error
+		for attempt := 0; attempt < 5; attempt++ {
+			if attempt > 0 && !sleepCtx(ctx, time.Duration(1<<attempt)*500*time.Millisecond) { // 1s, 2s, 4s, 8s
+				break
+			}
+			if err = s.post(ctx, body); err == nil {
+				s.ingested.Add(int64(lines))
+				s.sent()
+				return nil
+			}
+			s.sendFailed(err)
+		}
+		return err
+	}
+
+	var postErr error
+	if waiting, _ := s.spool.Pending(); waiting == 0 {
+		if postErr = s.post(ctx, body); postErr == nil {
+			s.ingested.Add(int64(lines))
+			s.sent()
+			return nil
+		}
+		s.sendFailed(postErr)
+	}
+	err := s.spool.Write(body, lines)
+	if err == nil {
+		select {
+		case s.spooled <- struct{}{}:
+		default:
+		}
+		return nil
+	}
+	if postErr != nil {
+		return fmt.Errorf("%v; %v", postErr, err)
+	}
+	// Spool full while older batches wait: one direct attempt before dropping.
+	if postErr = s.post(ctx, body); postErr == nil {
+		s.ingested.Add(int64(lines))
+		return nil
+	}
+	return fmt.Errorf("%v; %v", err, postErr)
+}
+
+// replay sends the spooled batches back to VictoriaLogs, oldest first, with
+// an increasing pause (up to 30 s) while it keeps failing.
+func (s *Store) replay(ctx context.Context) {
+	if n, size := s.spool.Pending(); n > 0 {
+		logEvent("store", 5, "disk spool: %d messages (%d bytes) waiting from a previous run", n, size)
+	}
+	backoff := time.Second
+	for {
+		f, body, ok, err := s.spool.Oldest()
+		if err != nil {
+			logEvent("store", 4, "disk spool: %v", err)
+		}
+		if !ok {
+			select {
+			case <-ctx.Done():
+				return
+			case <-s.spooled:
+			case <-time.After(time.Minute):
+			}
+			continue
+		}
+		err = s.post(ctx, body)
+		switch {
+		case err == nil:
+			s.spool.Remove(f)
+			s.ingested.Add(f.lines)
+			s.sent()
+			backoff = time.Second
+			continue
+		case isRejected(err):
+			// VictoriaLogs refuses the data itself: sending it again would not help.
+			s.spool.Remove(f)
+			s.dropped.Add(f.lines)
+			logEvent("store", 3, "disk spool: %d messages refused by VictoriaLogs and lost: %v", f.lines, err)
+			continue
+		}
+		s.sendFailed(err)
+		if !sleepCtx(ctx, backoff) {
+			return
+		}
+		backoff = min(2*backoff, 30*time.Second)
+	}
+}
+
+// sendFailed and sent report when VictoriaLogs stops and starts taking the
+// batches again, once per change.
+func (s *Store) sendFailed(err error) {
+	s.lastErr.Store(err.Error())
+	if !s.failing.Swap(true) {
+		if s.spool != nil {
+			logEvent("store", 4, "VictoriaLogs unreachable, batches are kept in the disk spool: %v", err)
+		} else {
+			logEvent("store", 4, "VictoriaLogs unreachable, retrying: %v", err)
+		}
+	}
+}
+
+func (s *Store) sent() {
+	s.lastErr.Store("")
+	if s.failing.Swap(false) {
+		logEvent("store", 5, "VictoriaLogs reachable again")
+	}
+}
+
+func encodeBatch(batch []*Entry) ([]byte, error) {
 	var buf bytes.Buffer
 	enc := json.NewEncoder(&buf)
 	enc.SetEscapeHTML(false)
 	for _, e := range batch {
 		if err := enc.Encode(e.Record()); err != nil {
-			return err
+			return nil, err
 		}
 	}
-	u := s.base + "/insert/jsonline?_stream_fields=host,app&_msg_field=_msg&_time_field=_time"
-
-	var err error
-	for attempt := 0; attempt < 5; attempt++ {
-		if attempt > 0 {
-			time.Sleep(time.Duration(1<<attempt) * 500 * time.Millisecond) // 1s, 2s, 4s, 8s
-		}
-		if err = s.post(u, buf.Bytes()); err == nil {
-			return nil
-		}
-	}
-	return err
+	return buf.Bytes(), nil
 }
 
-func (s *Store) post(u string, body []byte) error {
-	resp, err := s.client.Post(u, "application/stream+json", bytes.NewReader(body))
+// insertError is an error status of VictoriaLogs to an insert.
+type insertError struct {
+	status int
+	msg    string
+}
+
+func (e *insertError) Error() string { return fmt.Sprintf("HTTP %d: %s", e.status, e.msg) }
+
+// isRejected tells whether VictoriaLogs refused the data itself (4xx other
+// than 429), as opposed to being unreachable or overloaded.
+func isRejected(err error) bool {
+	var ie *insertError
+	return errors.As(err, &ie) && ie.status >= 400 && ie.status < 500 && ie.status != http.StatusTooManyRequests
+}
+
+func (s *Store) post(ctx context.Context, body []byte) error {
+	u := s.base + "/insert/jsonline?_stream_fields=host,app&_msg_field=_msg&_time_field=_time"
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, u, bytes.NewReader(body))
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/stream+json")
+	resp, err := s.client.Do(req)
 	if err != nil {
 		return err
 	}
 	defer resp.Body.Close()
 	if resp.StatusCode/100 != 2 {
 		msg, _ := io.ReadAll(io.LimitReader(resp.Body, 512))
-		return fmt.Errorf("HTTP %d: %s", resp.StatusCode, strings.TrimSpace(string(msg)))
+		return &insertError{status: resp.StatusCode, msg: strings.TrimSpace(string(msg))}
 	}
 	_, _ = io.Copy(io.Discard, resp.Body)
 	return nil
@@ -265,11 +424,15 @@ func queryStatus(err error) int {
 }
 
 func (s *Store) Stats() map[string]any {
-	return map[string]any{
+	st := map[string]any{
 		"received":  s.received.Load(),
 		"ingested":  s.ingested.Load(),
 		"dropped":   s.dropped.Load(),
 		"queue":     len(s.in),
 		"lastError": s.lastErr.Load(),
 	}
+	if s.spool != nil {
+		st["spooled"], st["spoolBytes"] = s.spool.Pending()
+	}
+	return st
 }

store_test.go

@@ -0,0 +1,216 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+// insertVL plays VictoriaLogs' insert endpoint: it answers `status` (0 = the
+// connection fails) and keeps the lines it accepted.
+type insertVL struct {
+	mu     sync.Mutex
+	status int
+	lines  []string
+}
+
+func (v *insertVL) set(status int) {
+	v.mu.Lock()
+	v.status = status
+	v.mu.Unlock()
+}
+
+func (v *insertVL) got() []string {
+	v.mu.Lock()
+	defer v.mu.Unlock()
+	return append([]string(nil), v.lines...)
+}
+
+func (v *insertVL) RoundTrip(r *http.Request) (*http.Response, error) {
+	body, _ := io.ReadAll(r.Body)
+	v.mu.Lock()
+	defer v.mu.Unlock()
+	if v.status == 0 {
+		return nil, errors.New("connection refused")
+	}
+	if v.status == http.StatusOK {
+		for _, l := range strings.Split(strings.TrimSpace(string(body)), "\n") {
+			v.lines = append(v.lines, l)
+		}
+	}
+	return &http.Response{StatusCode: v.status, Body: io.NopCloser(strings.NewReader("")), Header: http.Header{}}, nil
+}
+
+func testEntry(msg string, done *atomic.Int64) *Entry {
+	e := &Entry{Received: time.Now(), Time: time.Now(), Host: "h", App: "a", Message: msg}
+	if done != nil {
+		e.Done = func() { done.Add(1) }
+	}
+	return e
+}
+
+func waitFor(t *testing.T, what string, cond func() bool) {
+	t.Helper()
+	for deadline := time.Now().Add(5 * time.Second); time.Now().Before(deadline); time.Sleep(10 * time.Millisecond) {
+		if cond() {
+			return
+		}
+	}
+	t.Fatalf("timed out waiting for %s", what)
+}
+
+func TestSpoolFiles(t *testing.T) {
+	dir := t.TempDir()
+	sp, err := OpenSpool(dir, 100)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := sp.Write([]byte("a\nb\n"), 2); err != nil {
+		t.Fatal(err)
+	}
+	if err := sp.Write([]byte("c\n"), 1); err != nil {
+		t.Fatal(err)
+	}
+	if err := sp.Write(bytes.Repeat([]byte("x"), 100), 1); !errors.Is(err, errSpoolFull) {
+		t.Fatalf("write over the limit: %v, want errSpoolFull", err)
+	}
+	_ = os.WriteFile(filepath.Join(dir, "broken.ndjson.tmp"), []byte("z"), 0o644)
+
+	// A new run finds the batches left on disk and drops unfinished writes.
+	sp, err = OpenSpool(dir, 100)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if n, size := sp.Pending(); n != 3 || size != 6 {
+		t.Fatalf("pending %d lines %d bytes, want 3 and 6", n, size)
+	}
+	f, body, ok, err := sp.Oldest()
+	if !ok || err != nil || string(body) != "a\nb\n" || f.lines != 2 {
+		t.Fatalf("oldest: %q %+v %v %v", body, f, ok, err)
+	}
+	sp.Remove(f)
+	if _, body, _, _ := sp.Oldest(); string(body) != "c\n" {
+		t.Fatalf("next oldest %q", body)
+	}
+	if _, err := os.Stat(filepath.Join(dir, "broken.ndjson.tmp")); !os.IsNotExist(err) {
+		t.Error("unfinished write left in the spool")
+	}
+}
+
+func TestStoreSpoolsWhileVictoriaLogsIsDown(t *testing.T) {
+	sp, err := OpenSpool(t.TempDir(), 1<<20)
+	if err != nil {
+		t.Fatal(err)
+	}
+	vl := &insertVL{status: 0}
+	s := NewStore("http://vl", 2, 100, 20*time.Millisecond, sp)
+	s.client.Transport = vl
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go s.Run(ctx)
+
+	var done atomic.Int64
+	for _, m := range []string{"one", "two", "three"} {
+		s.Enqueue(testEntry(m, &done))
+	}
+	// VictoriaLogs is down: the messages are kept on disk, and acknowledged.
+	waitFor(t, "3 spooled messages", func() bool { n, _ := sp.Pending(); return n == 3 })
+	if done.Load() != 3 || s.dropped.Load() != 0 {
+		t.Fatalf("done %d dropped %d, want 3 and 0", done.Load(), s.dropped.Load())
+	}
+	// While batches wait on disk, new ones queue behind them.
+	vl.set(http.StatusServiceUnavailable)
+	s.Enqueue(testEntry("four", &done))
+	waitFor(t, "4 spooled messages", func() bool { n, _ := sp.Pending(); return n == 4 })
+
+	vl.set(http.StatusOK)
+	waitFor(t, "the spool to drain", func() bool { n, _ := sp.Pending(); return n == 0 })
+	got := strings.Join(vl.got(), "\n")
+	for i, m := range []string{"one", "two", "three", "four"} {
+		if !strings.Contains(got, `"_msg":"`+m+`"`) {
+			t.Errorf("message %d %q not sent: %s", i, m, got)
+		}
+	}
+	if strings.Index(got, `"one"`) > strings.Index(got, `"four"`) {
+		t.Error("spooled batches sent out of order")
+	}
+	if s.ingested.Load() != 4 || s.lastErr.Load() != "" {
+		t.Errorf("ingested %d lastErr %q", s.ingested.Load(), s.lastErr.Load())
+	}
+
+	// Once the spool is empty, batches go straight to VictoriaLogs again.
+	s.Enqueue(testEntry("five", &done))
+	waitFor(t, "a direct insert", func() bool { return s.ingested.Load() == 5 })
+}
+
+func TestStoreDropsRefusedSpooledBatch(t *testing.T) {
+	sp, _ := OpenSpool(t.TempDir(), 1<<20)
+	_ = sp.Write([]byte("{bad json\n"), 1)
+	vl := &insertVL{status: http.StatusBadRequest}
+	s := NewStore("http://vl", 10, 10, time.Second, sp)
+	s.client.Transport = vl
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	go s.Run(ctx)
+	waitFor(t, "the refused batch to be dropped", func() bool { return s.dropped.Load() == 1 })
+	if n, _ := sp.Pending(); n != 0 {
+		t.Errorf("%d messages left in the spool", n)
+	}
+}
+
+func TestStoreWithoutSpoolDrops(t *testing.T) {
+	vl := &insertVL{status: 0}
+	s := NewStore("http://vl", 10, 10, time.Hour, nil)
+	s.client.Transport = vl
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // shutdown: one attempt, no retry pauses
+	var done atomic.Int64
+	s.store(ctx, []*Entry{testEntry("x", &done)})
+	if done.Load() != 0 || s.dropped.Load() != 1 {
+		t.Errorf("done %d dropped %d, want 0 and 1", done.Load(), s.dropped.Load())
+	}
+}
+
+func TestEnqueueWait(t *testing.T) {
+	s := NewStore("http://vl", 10, 1, time.Hour, nil)
+	s.Enqueue(testEntry("fills the queue", nil))
+	s.Enqueue(testEntry("syslog: dropped", nil))
+	if s.dropped.Load() != 1 {
+		t.Fatalf("dropped %d, want 1", s.dropped.Load())
+	}
+	// A producer that can wait blocks until there is room…
+	queued := make(chan struct{})
+	go func() {
+		e := testEntry("docker: waits", nil)
+		e.Wait = true
+		s.Enqueue(e)
+		close(queued)
+	}()
+	select {
+	case <-queued:
+		t.Fatal("did not wait for room in the queue")
+	case <-time.After(50 * time.Millisecond):
+	}
+	<-s.in
+	<-queued
+	if s.dropped.Load() != 1 {
+		t.Errorf("dropped %d, want 1", s.dropped.Load())
+	}
+	// …or until shutdown.
+	close(s.quit)
+	e := testEntry("docker: shutdown", nil)
+	e.Wait = true
+	s.Enqueue(e)
+	if s.dropped.Load() != 2 {
+		t.Errorf("dropped %d after shutdown, want 2", s.dropped.Load())
+	}
+}

syslog.go

@@ -36,8 +36,14 @@ type Entry struct {
 	Proto    string // udp or tcp
 	HostIP   string // original host value when it was an IP resolved through DNS
 
-	SourceType string            // "syslog" or "docker"
+	SourceType string            // "syslog", "docker", "host", "kernel", "audit", "file" or "logstream"
 	Extra      map[string]string // additional fields (docker: container, image, …)
+
+	// Not stored. Wait: the producer can be slowed down when the queue is full
+	// (Docker, host logs) instead of losing the message. Done: called once the
+	// message is stored in VictoriaLogs or in the disk spool.
+	Wait bool
+	Done func()
 }
 
 // Record returns the entry in the shape stored in VictoriaLogs and returned by the API.
@@ -233,7 +239,7 @@ func serveUDP(ctx context.Context, pc net.PacketConn, sink func(*Entry)) {
 			if ctx.Err() != nil {
 				return
 			}
-			log.Printf("syslog udp: %v", err)
+			logEvent("syslog", 4, "UDP read error: %v", err)
 			time.Sleep(100 * time.Millisecond)
 			continue
 		}
@@ -241,21 +247,51 @@ func serveUDP(ctx context.Context, pc net.PacketConn, sink func(*Entry)) {
 	}
 }
 
+// TCP limits: connections open at once, and how long a connection may stay
+// silent before it is closed (senders reconnect on their own).
+var (
+	tcpMaxConns = 512
+	tcpIdle     = 30 * time.Minute
+)
+
 func serveTCP(ctx context.Context, ln net.Listener, sink func(*Entry)) {
+	slots := make(chan struct{}, tcpMaxConns)
 	for {
 		conn, err := ln.Accept()
 		if err != nil {
 			if ctx.Err() != nil {
 				return
 			}
-			log.Printf("syslog tcp: %v", err)
+			logEvent("syslog", 4, "TCP accept error: %v", err)
 			time.Sleep(100 * time.Millisecond)
 			continue
 		}
-		go handleTCP(ctx, conn, sink)
+		select {
+		case slots <- struct{}{}:
+		default:
+			logEvent("syslog", 4, "%d TCP connections already open, refusing %s", tcpMaxConns, conn.RemoteAddr())
+			conn.Close()
+			continue
+		}
+		go func() {
+			defer func() { <-slots }()
+			handleTCP(ctx, conn, sink)
+		}()
 	}
 }
 
+// idleConn pushes the read deadline back before each read, so only a
+// connection that stays silent for tcpIdle is closed.
+type idleConn struct {
+	net.Conn
+	idle time.Duration
+}
+
+func (c idleConn) Read(p []byte) (int, error) {
+	_ = c.Conn.SetReadDeadline(time.Now().Add(c.idle))
+	return c.Conn.Read(p)
+}
+
 const maxFrame = 1 << 20
 
 // handleTCP supports both RFC 6587 framings: octet counting
@@ -266,7 +302,7 @@ func handleTCP(ctx context.Context, conn net.Conn, sink func(*Entry)) {
 	defer stop()
 
 	src := hostOf(conn.RemoteAddr())
-	r := bufio.NewReaderSize(conn, 64*1024)
+	r := bufio.NewReaderSize(idleConn{conn, tcpIdle}, 64*1024)
 	for {
 		c, err := r.ReadByte()
 		if err != nil {

syslogserver.go

@@ -94,7 +94,7 @@ func (s *SyslogServer) apply() {
 		pc, err := net.ListenPacket("udp", s.addr)
 		if err != nil {
 			s.errUDP = err.Error()
-			log.Printf("syslog udp: %v", err)
+			logEvent("syslog", 3, "UDP listener failed: %v", err)
 		} else {
 			if uc, ok := pc.(*net.UDPConn); ok {
 				_ = uc.SetReadBuffer(8 << 20)
@@ -108,7 +108,7 @@ func (s *SyslogServer) apply() {
 		ln, err := net.Listen("tcp", s.addr)
 		if err != nil {
 			s.errTCP = err.Error()
-			log.Printf("syslog tcp: %v", err)
+			logEvent("syslog", 3, "TCP listener failed: %v", err)
 		} else {
 			s.ln = ln
 			go serveTCP(ctx, ln, s.sink)

tags.go

@@ -30,7 +30,6 @@ func defaultTags() []Tag {
 	return []Tag{
 		{ID: "warning", Code: "01", Pattern: "warning", Color: "#fdba74", WholeWord: true, Enabled: true},
 		{ID: "error", Code: "02", Pattern: "error", Color: "#fca5a5", WholeWord: true, Enabled: true},
-		{ID: "ok", Code: "03", Pattern: "ok", Color: "#86efac", WholeWord: true, Enabled: true},
 	}
 }
 
@@ -218,6 +217,51 @@ func (s *TagStore) Delete(id string) error {
 	return errTagNotFound
 }
 
+// tagListError tells which tag of a list (PUT /api/tags) is invalid.
+type tagListError struct {
+	index int
+	err   error
+}
+
+func (e *tagListError) Error() string { return e.err.Error() }
+func (e *tagListError) Unwrap() error { return e.err }
+
+// Replace saves a whole list at once (the Save button of the settings). A tag
+// whose id is known keeps its code; the others get a new id and a free code.
+// Nothing is saved when a tag is invalid: the error gives its position.
+func (s *TagStore) Replace(in []Tag) ([]Tag, error) {
+	if len(in) > 99 {
+		return nil, errTooManyTags
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	codes := map[string]string{}
+	for _, t := range s.tags {
+		codes[t.ID] = t.Code
+	}
+	out := make([]Tag, len(in))
+	seen := map[string]bool{}
+	for i, t := range in {
+		if err := t.validate(); err != nil {
+			return nil, &tagListError{index: i, err: err}
+		}
+		if c, ok := codes[t.ID]; ok && !seen[t.ID] {
+			t.Code = c
+		} else {
+			t.ID, t.Code = newID(), ""
+		}
+		seen[t.ID] = true
+		out[i] = t
+	}
+	for i := range out {
+		if out[i].Code == "" {
+			out[i].Code = freeCode(out)
+		}
+	}
+	s.tags = out
+	return append([]Tag(nil), out...), s.save()
+}
+
 func (s *TagStore) Reset() ([]Tag, error) {
 	s.mu.Lock()
 	defer s.mu.Unlock()

tags_test.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"errors"
 	"os"
 	"path/filepath"
 	"slices"
@@ -52,3 +53,37 @@ func TestTagCodes(t *testing.T) {
 		t.Fatalf("reloaded code = %q, want 07", got)
 	}
 }
+
+func TestTagReplace(t *testing.T) {
+	s, err := LoadTagStore(filepath.Join(t.TempDir(), "tags.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	// Defaults: warning 01, error 02. Keep error, drop warning, add two tags
+	// (one with an unknown id, one repeating a known id).
+	got, err := s.Replace([]Tag{
+		{ID: "new1", Pattern: "a", Color: "#000000"},
+		{ID: "error", Code: "42", Pattern: "error", Color: "#111111", Enabled: true},
+		{ID: "error", Pattern: "b", Color: "#000000"},
+	})
+	if err != nil {
+		t.Fatal(err)
+	}
+	codes := []string{got[0].Code, got[1].Code, got[2].Code}
+	if want := []string{"01", "02", "03"}; !slices.Equal(codes, want) {
+		t.Fatalf("codes = %v, want %v", codes, want)
+	}
+	if got[1].ID != "error" || got[0].ID == "new1" || got[2].ID == "error" || got[1].Color != "#111111" {
+		t.Fatalf("ids/fields = %+v", got)
+	}
+
+	// An invalid tag saves nothing and gives its position.
+	_, err = s.Replace([]Tag{{Pattern: "ok", Color: "#000000"}, {Pattern: "(", Regex: true, Color: "#000000"}})
+	var le *tagListError
+	if !errors.As(err, &le) || le.index != 1 {
+		t.Fatalf("err = %v, want tagListError at 1", err)
+	}
+	if n := len(s.List()); n != 3 {
+		t.Fatalf("list after a failed Replace has %d tags, want 3", n)
+	}
+}

web/index.html

@@ -41,6 +41,7 @@
         <svg class="sun" viewBox="0 0 24 24"><circle cx="12" cy="12" r="4"/><path d="M12 2v2M12 20v2M4.9 4.9l1.4 1.4M17.7 17.7l1.4 1.4M2 12h2M20 12h2M4.9 19.1l1.4-1.4M17.7 6.3l1.4-1.4"/></svg>
         <svg class="moon" viewBox="0 0 24 24"><path d="M21 12.8A9 9 0 1 1 11.2 3a7 7 0 0 0 9.8 9.8z"/></svg>
       </button>
+      <span id="whoami" class="whoami" hidden><span class="who-name"></span><span class="who-badge"></span></span>
       <a id="logoutBtn" class="icon-btn" href="/auth/logout" hidden data-i18n-title="logout" data-i18n-aria="logout">
         <!-- Log out icon (Lucide "log-out", ISC license) -->
         <svg viewBox="0 0 24 24"><path d="M9 21H5a2 2 0 0 1-2-2V5a2 2 0 0 1 2-2h4"/><path d="m16 17 5-5-5-5"/><path d="M21 12H9"/></svg>
@@ -50,6 +51,33 @@
   </header>
 
   <section class="filters">
+    <div id="viewMode" class="seg view-mode" role="radiogroup" data-i18n-aria="viewAria">
+      <button type="button" role="radio" data-view="stream" data-i18n-title="viewStreamTitle">
+        <!-- Lucide "radio" (ISC license) -->
+        <svg viewBox="0 0 24 24" aria-hidden="true"><path d="M4.9 19.1C1 15.2 1 8.8 4.9 4.9"/><path d="M7.8 16.2c-2.3-2.3-2.3-6.1 0-8.5"/><circle cx="12" cy="12" r="2"/><path d="M16.2 7.8c2.3 2.3 2.3 6.1 0 8.5"/><path d="M19.1 4.9C23 8.8 23 15.1 19.1 19"/></svg>
+        <span data-i18n="viewStream">Stream</span>
+      </button>
+      <button type="button" role="radio" data-view="period" data-i18n-title="viewPeriodTitle">
+        <!-- Lucide "calendar-range" (ISC license) -->
+        <svg viewBox="0 0 24 24" aria-hidden="true"><rect width="18" height="18" x="3" y="4" rx="2"/><path d="M16 2v4M3 10h18M8 2v4M17 14h-6M13 18H7M7 14h.01M17 18h.01"/></svg>
+        <span data-i18n="viewPeriod">Time range</span>
+      </button>
+    </div>
+    <div id="period" class="period" hidden>
+      <button id="perPrev" class="btn tool" type="button" data-i18n-title="perPrev" data-i18n-aria="perPrev">
+        <svg viewBox="0 0 24 24" aria-hidden="true"><path d="m15 18-6-6 6-6"/></svg>
+      </button>
+      <input id="perFrom" type="datetime-local" data-i18n-title="perFrom" data-i18n-aria="perFrom">
+      <span class="muted" aria-hidden="true">→</span>
+      <input id="perTo" type="datetime-local" data-i18n-title="perTo" data-i18n-aria="perTo">
+      <button id="perNext" class="btn tool" type="button" data-i18n-title="perNext" data-i18n-aria="perNext">
+        <svg viewBox="0 0 24 24" aria-hidden="true"><path d="m9 18 6-6-6-6"/></svg>
+      </button>
+      <button id="perOut" class="btn tool" type="button" data-i18n-title="perOut" data-i18n-aria="perOut">
+        <!-- Lucide "zoom-out" (ISC license) -->
+        <svg viewBox="0 0 24 24" aria-hidden="true"><circle cx="11" cy="11" r="8"/><path d="m21 21-4.3-4.3M8 11h6"/></svg>
+      </button>
+    </div>
     <select id="range" data-i18n-aria="rangeAria">
       <option value="5m" data-i18n="r5m">5 min</option>
       <option value="15m" data-i18n="r15m">15 min</option>
@@ -75,6 +103,10 @@
       <option value="syslog">Syslog</option>
       <option value="docker">Docker</option>
       <option value="host" data-i18n="srcHost">Host system</option>
+      <option value="kernel" data-i18n="srcKernel">Kernel (dmesg)</option>
+      <option value="audit">Audit</option>
+      <option value="file" data-i18n="srcFile">Files</option>
+      <option value="logstream">LogStream</option>
     </select>
     <span class="spacer"></span>
     <span id="count" class="muted"></span>
@@ -97,17 +129,24 @@
 
   <section id="histo" class="histo" data-i18n-aria="histoAria" hidden></section>
 
+  <div id="authWarn" class="auth-warn" role="status" hidden>
+    <span data-i18n="authOff"></span>
+    <button id="authWarnClose" class="icon-btn" type="button" data-i18n-aria="close">
+      <svg viewBox="0 0 24 24"><path d="M6 6l12 12M18 6 6 18"/></svg>
+    </button>
+  </div>
   <div id="error" class="error-banner" hidden></div>
   <button id="newPill" class="pill" type="button" hidden></button>
 
   <div id="table" class="table" hidden>
     <div id="listHead" class="list-head" role="presentation">
+      <span data-col="src"><span class="lbl" data-i18n="colSrc">Source</span></span>
       <span data-col="rcv"><span class="lbl" data-i18n="colRcv">Received</span><i class="grip" data-i18n-title="colGrip"></i></span>
       <span data-col="mt"><span class="lbl" data-i18n="colMt">Message time</span><i class="grip" data-i18n-title="colGrip"></i></span>
       <span data-col="sev"><span class="lbl" data-i18n="colSev">Severity</span><i class="grip" data-i18n-title="colGrip"></i></span>
       <span data-col="host"><span class="lbl" data-i18n="colHost">Host</span><i class="grip" data-i18n-title="colGrip"></i></span>
       <span data-col="app"><span class="lbl" data-i18n="colApp">App</span><i class="grip" data-i18n-title="colGrip"></i></span>
-      <span data-col="codes"><span class="lbl" data-i18n="colCodes" data-i18n-title="codesTitle">Filters</span></span>
+      <span data-col="codes"><span class="lbl" data-i18n="colCodes" data-i18n-title="codesTitle">Pattern</span></span>
       <span data-col="msg"><span class="lbl" data-i18n="colMsg">Message</span></span>
     </div>
     <main id="list" class="list"></main>
@@ -136,6 +175,7 @@
       </header>
 
       <div class="set-body">
+        <div class="set-side">
         <nav id="setNav" class="set-nav" role="tablist" aria-orientation="vertical">
           <button type="button" role="tab" data-tab="locale">
             <svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="9"/><path d="M3 12h18M12 3a14 14 0 0 1 0 18M12 3a14 14 0 0 0 0 18"/></svg>
@@ -143,21 +183,30 @@
           </button>
           <button type="button" role="tab" data-tab="filters">
             <svg viewBox="0 0 24 24"><path d="M3 12V4a1 1 0 0 1 1-1h8l9 9-9 9z"/><circle cx="8" cy="8" r="1.5"/></svg>
-            <span data-i18n="tabFilters">Filters</span>
+            <span data-i18n="tabFilters">Patterns</span>
           </button>
           <button type="button" role="tab" data-tab="sources">
             <svg viewBox="0 0 24 24"><path d="M21 8 12 3 3 8v8l9 5 9-5z"/><path d="m3 8 9 5 9-5M12 13v8"/></svg>
-            <span data-i18n="tabSources">Sources</span>
+            <span data-i18n="tabSources">Log sources</span>
           </button>
           <button type="button" role="tab" data-tab="interface">
             <svg viewBox="0 0 24 24"><rect x="3" y="4" width="18" height="12" rx="2"/><path d="M8 20h8M12 16v4"/></svg>
-            <span data-i18n="tabInterface">Interface</span>
+            <span data-i18n="tabInterface">Appearance</span>
           </button>
           <button type="button" role="tab" data-tab="data">
             <svg viewBox="0 0 24 24"><ellipse cx="12" cy="5" rx="8" ry="3"/><path d="M4 5v14c0 1.7 3.6 3 8 3s8-1.3 8-3V5M4 12c0 1.7 3.6 3 8 3s8-1.3 8-3"/></svg>
-            <span data-i18n="tabData">Data</span>
+            <span data-i18n="tabData">Database</span>
           </button>
         </nav>
+        <div id="setActions" class="set-actions">
+          <button id="setSave" class="btn save" type="button" disabled>
+            <svg viewBox="0 0 24 24" aria-hidden="true"><path d="M5 12.5 10 17l9-10"/></svg>
+            <span data-i18n="saveSettings">Save</span>
+          </button>
+          <button id="setCancel" class="btn ghost" type="button" disabled data-i18n="cancelSettings">Cancel</button>
+          <p id="setState" class="set-state" role="status"></p>
+        </div>
+        </div>
 
         <div class="set-panels">
           <!-- Localization -->
@@ -182,26 +231,23 @@
             </section>
           </div>
 
-          <!-- Filters -->
-          <div class="set-panel" role="tabpanel" data-panel="filters" hidden>
-            <section class="set-section">
-              <h3 data-i18n="tagsTitle">Color tags</h3>
+          <!-- Pattern (color tags; the "filters" tab id is kept for saved settings) -->
+          <div class="set-panel wide" role="tabpanel" data-panel="filters" hidden>
+            <section class="set-section tags-section">
+              <div class="sec-head">
+                <h3 data-i18n="tagsTitle">Color tags</h3>
+                <span id="tagCount" class="muted small"></span>
+              </div>
               <p class="muted small" data-i18n="tagsHelp"></p>
-              <div id="tagList" class="tag-list"></div>
-              <footer>
-                <span class="tag-add">
-                  <button id="addTag" class="btn primary" type="button" data-i18n="addTag">+ Add tag</button>
-                  <select id="presetTags" class="field" aria-label="Presets" data-i18n-aria="presetAria">
-                    <option value="" data-i18n="presetPick">+ Preset…</option>
-                    <option value="http_status" data-i18n="preset_http_status">HTTP status codes</option>
-                    <option value="http_methods" data-i18n="preset_http_methods">HTTP methods</option>
-                    <option value="http_probes" data-i18n="preset_http_probes">Probes and attacks</option>
-                    <option value="http_bots" data-i18n="preset_http_bots">Bots and scripts</option>
-                    <option value="http_errors" data-i18n="preset_http_errors">TLS/HTTPS and proxy errors</option>
-                  </select>
-                </span>
+              <div class="tag-toolbar">
+                <button id="addTag" class="btn primary" type="button" data-i18n="addTag">+ Add tag</button>
+                <select id="presetTags" class="field" aria-label="Presets" data-i18n-aria="presetAria">
+                  <option value="" data-i18n="presetPick">+ Preset…</option>
+                </select>
+                <input id="tagFilter" type="search" class="dk-filter" autocomplete="off" spellcheck="false" data-i18n-ph="tagFilter" data-i18n-aria="tagFilter">
                 <button id="resetTags" class="btn ghost" type="button" data-i18n="resetTags">Restore default tags</button>
-              </footer>
+              </div>
+              <div id="tagList" class="tag-list"></div>
             </section>
           </div>
 
@@ -236,6 +282,58 @@
             </section>
 
             <section class="set-section">
+              <h3 data-i18n="dmesgTitle">Kernel messages (dmesg)</h3>
+              <p id="dmesgStatus" class="docker-status"></p>
+              <label class="switch-row">
+                <input id="dmesgEnabled" type="checkbox" class="switch">
+                <span data-i18n="dmesgEnabled">Collect the kernel messages of this machine</span>
+              </label>
+              <p class="muted small" data-i18n="dmesgHelp"></p>
+            </section>
+
+            <section class="set-section">
+              <h3 data-i18n="auditTitle">Linux audit (auditd)</h3>
+              <p id="auditStatus" class="docker-status"></p>
+              <label class="switch-row">
+                <input id="auditEnabled" type="checkbox" class="switch">
+                <span data-i18n="auditEnabled">Collect the audit events of this machine</span>
+              </label>
+              <div class="sl-grid">
+                <label class="lbl" for="auditPath" data-i18n="auditPath">File</label>
+                <input id="auditPath" type="text" class="dk-filter" autocomplete="off" spellcheck="false">
+              </div>
+              <p class="muted small src-help" data-i18n="auditHelp"></p>
+            </section>
+
+            <section class="set-section">
+              <h3 data-i18n="selfTitle">LogStream internal logs</h3>
+              <p id="selfStatus" class="docker-status"></p>
+              <label class="switch-row">
+                <input id="selfEnabled" type="checkbox" class="switch">
+                <span data-i18n="selfEnabled">Record the events of LogStream itself</span>
+              </label>
+              <div class="sl-grid">
+                <label class="lbl" for="selfLevel" data-i18n="selfLevel">Minimum level</label>
+                <select id="selfLevel" class="field self-level">
+                  <option value="err" data-i18n="sev3">Errors and above</option>
+                  <option value="warning" data-i18n="sev4">Warnings and above</option>
+                  <option value="notice" data-i18n="sev5">Notice and above</option>
+                  <option value="info" data-i18n="sev6">Info and above</option>
+                </select>
+              </div>
+              <p class="muted small src-help" data-i18n="selfHelp"></p>
+            </section>
+
+            <section class="set-section span">
+              <h3 data-i18n="filesTitle">Log files</h3>
+              <div id="fileList" class="file-list"></div>
+              <div class="file-toolbar">
+                <button id="addFile" class="btn primary" type="button" data-i18n="addFile">+ Add a file</button>
+              </div>
+              <p class="muted small src-help" data-i18n="filesHelp"></p>
+            </section>
+
+            <section class="set-section span">
               <h3 data-i18n="dockerTitle">Docker containers</h3>
               <p id="dockerStatus" class="docker-status"></p>
               <div id="dockerBody" hidden>
@@ -272,7 +370,7 @@
               </div>
               <p class="muted small hint" data-i18n="themeHelp"></p>
             </section>
-            <section class="set-section">
+            <section class="set-section span">
               <h3 data-i18n="logDisplay">Log display</h3>
               <div class="field-grid">
                 <span class="lbl" data-i18n="fontSize">Font size</span>
@@ -333,9 +431,14 @@
           </div>
 
           <!-- Data -->
-          <div class="set-panel" role="tabpanel" data-panel="data" hidden>
+          <div class="set-panel wide" role="tabpanel" data-panel="data" hidden>
             <section class="set-section danger">
               <h3 data-i18n="dangerZone">Danger zone</h3>
+              <div class="db-head">
+                <span class="lbl" data-i18n="dbTitle">Database</span>
+                <button id="dbRefresh" class="link-btn" type="button" data-i18n="dbRefresh">Refresh</button>
+              </div>
+              <dl id="dbStats" class="db-stats"></dl>
               <p class="muted small" data-i18n="purgeHelp"></p>
               <div class="purge-row">
                 <button id="purgeBtn" class="btn danger" type="button" data-i18n="purgeBtn">Delete all logs…</button>

web/style.css

@@ -22,6 +22,14 @@
   --hit: rgba(99, 102, 241, .18);
   --shadow: 0 10px 30px rgba(15, 23, 42, .12);
   --chip-l: 38%;            /* lightness of project-colored text (labels, Docker apps) */
+  --src-syslog: #64748b;    /* source badges: syslog received over the network */
+  --src-docker: #1d6fd6;    /* Docker containers */
+  --src-kernel: #b4540a;    /* kernel ring buffer (dmesg) */
+  --src-host: #b0407a;      /* /var/log files of the host system */
+  --src-audit: #7c4dbd;     /* audit events (auditd) */
+  --src-ls: #1f9aa3;        /* LogStream internal logs */
+  --src-file: #5f8a1f;      /* log files (Settings > Sources > Log files) */
+  --src-tint: 6%;           /* background tint of their rows */
 
   --sev-crit: #be123c;
   --sev-err: #dc2626;
@@ -70,6 +78,14 @@
   --hit: rgba(129, 140, 248, .28);
   --shadow: 0 10px 30px rgba(0, 0, 0, .5);
   --chip-l: 70%;
+  --src-syslog: #94a3b8;
+  --src-docker: #5aa2f5;
+  --src-kernel: #e7a25a;
+  --src-host: #e58bbb;
+  --src-audit: #a983e6;
+  --src-ls: #3cc3cc;
+  --src-file: #9ccc54;
+  --src-tint: 9%;
   --sev-crit: #fb7185;
   --sev-err: #f87171;
   --sev-warning: #fbbf24;
@@ -102,6 +118,14 @@
     --hit: rgba(129, 140, 248, .28);
     --shadow: 0 10px 30px rgba(0, 0, 0, .5);
   --chip-l: 70%;
+    --src-syslog: #94a3b8;
+    --src-docker: #5aa2f5;
+    --src-kernel: #e7a25a;
+    --src-host: #e58bbb;
+    --src-audit: #a983e6;
+    --src-ls: #3cc3cc;
+    --src-file: #9ccc54;
+    --src-tint: 9%;
     --sev-crit: #fb7185;
     --sev-err: #f87171;
     --sev-warning: #fbbf24;
@@ -180,6 +204,16 @@ svg { fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round;
 .chip.on { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }
 
 .actions { display: flex; align-items: center; gap: 6px; margin-left: auto; }
+/* Logged-in user, with how they logged in (oidc / local) */
+.whoami { display: flex; align-items: center; gap: 6px; min-width: 0; margin-left: 6px; font-size: 13px; color: var(--muted); }
+.whoami .who-name { font-weight: 600; color: var(--text); max-width: 18ch; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
+.whoami .who-badge {
+  flex: none; border: 1px solid var(--border); border-radius: 6px;
+  padding: 1px 6px; font-size: 10.5px; font-weight: 650; letter-spacing: .02em;
+}
+.whoami .who-badge.oidc { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }
+.whoami .who-badge:empty { display: none; }
+.whoami.none .who-name { font-weight: 400; color: var(--muted); }
 .icon-btn {
   width: 36px; height: 36px; display: grid; place-items: center;
   border: 1px solid transparent; background: transparent; border-radius: 9px; color: var(--muted);
@@ -240,6 +274,19 @@ body.busy .progress::after {
   font-size: 13px; max-width: 220px;
 }
 .filters select.set { border-color: var(--accent); background-color: var(--accent-soft); }
+/* Display mode: Stream or Time range, then the start → end fields of the range */
+.view-mode { padding: 2px; gap: 2px; border-radius: 9px; }
+.view-mode button { display: inline-flex; align-items: center; gap: 6px; height: 26px; padding: 0 10px; }
+.view-mode svg { width: 15px; height: 15px; }
+.period { display: inline-flex; align-items: center; gap: 6px; }
+.period .btn.tool { width: 32px; padding: 0; justify-content: center; }
+.period input {
+  height: 32px; padding: 0 8px;
+  border: 1px solid var(--accent); border-radius: 8px; background: var(--accent-soft);
+  font-size: 13px; font-variant-numeric: tabular-nums; color-scheme: light dark;
+}
+.period input:focus { outline: 0; box-shadow: 0 0 0 3px var(--accent-soft); }
+.period input.bad { border-color: var(--sev-err); background: color-mix(in srgb, var(--sev-err) 10%, transparent); }
 .spacer { flex: 1; }
 #count { font-size: 12.5px; font-variant-numeric: tabular-nums; }
 
@@ -308,12 +355,12 @@ body.busy .progress::after {
 .list { margin: 6px 20px 0; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
 .list:empty { display: none; }
 
-/* Columns: received, message time, severity, host, app, tag codes, message. Widths come from
+/* Columns: source, received, message time, severity, host, app, tag codes, message. Widths come from
    --col-* (set on #table when a column has been resized, see app.js), shared by
    the header and every row through subgrid so that the columns line up. */
 .table {
   display: grid;
-  grid-template-columns: var(--col-rcv, max-content) var(--col-mt, max-content) var(--col-sev, 4.6rem)
+  grid-template-columns: minmax(3.9rem, max-content) var(--col-rcv, max-content) var(--col-mt, max-content) var(--col-sev, 4.6rem)
     var(--col-host, minmax(5rem, 9rem)) var(--col-app, minmax(4rem, 8rem)) var(--codes-w) minmax(0, 1fr);
   column-gap: 12px;
   margin: 6px 20px 0; background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius);
@@ -343,20 +390,19 @@ body.col-resizing, body.col-resizing * { cursor: col-resize !important; user-sel
 
 .row {
   display: grid;
-  grid-template-columns: max-content max-content 4.6rem minmax(5rem, 9rem) minmax(4rem, 8rem) var(--codes-w) 1fr;
+  grid-template-columns: max-content max-content max-content 4.6rem minmax(5rem, 9rem) minmax(4rem, 8rem) var(--codes-w) 1fr;
   gap: 0 12px; align-items: baseline;
-  padding: 5px 14px 5px 11px;
+  padding: 3px 14px 3px 11px;
   border-left: 3px solid transparent;
   border-bottom: 1px solid var(--border);
-  font-family: var(--log-font, var(--mono)); font-size: var(--log-size);
+  font-family: var(--log-font, var(--mono)); font-size: var(--log-size); line-height: 1.35;
   font-variant-ligatures: none; /* keep -> != etc. as typed */
   cursor: pointer;
 }
 .row:last-child { border-bottom: 0; }
 /* Settings > Interface > Density: compact fits about 50% more lines on screen */
-:root[data-density="compact"] .row { padding-top: 1px; padding-bottom: 1px; line-height: 1.25; }
-:root[data-density="compact"] .row .sev { padding-top: 0; padding-bottom: 0; line-height: 1.3; }
-:root[data-density="compact"] .row .codes b { padding-top: 0; padding-bottom: 0; line-height: 1.2; }
+:root[data-density="compact"] .row { padding-top: 1px; padding-bottom: 1px; line-height: 1.2; }
+:root[data-density="compact"] .row :is(.src-badge, .sev, .codes b) { line-height: 1.15; }
 .row:hover { background: var(--row-hover); }
 .row:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; }
 .row.new { animation: flash 1.2s ease-out; }
@@ -374,7 +420,7 @@ body.col-resizing, body.col-resizing * { cursor: col-resize !important; user-sel
 .sev {
   justify-self: start; max-width: 100%; overflow: hidden; text-overflow: ellipsis;
   font-size: 10.5px; font-weight: 700; text-transform: uppercase; letter-spacing: .03em;
-  padding: 1px 6px; border-radius: 5px;
+  padding: 0 6px; border-radius: 5px; line-height: 1.3;
   color: var(--sev); background: color-mix(in srgb, var(--sev) 14%, transparent);
 }
 .sev-crit    { --sev: var(--tag-error); --sev-text: var(--tag-error-text); }
@@ -388,14 +434,39 @@ body.col-resizing, body.col-resizing * { cursor: col-resize !important; user-sel
 .row.sev-crit, .row.sev-err, .row.sev-warning { border-left-color: var(--sev); }
 .row.sev-crit, .row.sev-err { background: color-mix(in srgb, var(--sev) 7%, transparent); }
 .row .host[data-act], .row .app[data-act] { cursor: pointer; }
+/* Source badge at the start of every row, fixed width, one color per source.
+   Audit events, log files and LogStream internal logs also get a colored edge
+   (over the severity one) and a light tint. */
+.row.src-syslog { --src: var(--src-syslog); }
+.row.src-docker { --src: var(--src-docker); }
+.row.src-kernel { --src: var(--src-kernel); }
+.row.src-host { --src: var(--src-host); }
+.row.src-audit { --src: var(--src-audit); }
+.row.src-logstream { --src: var(--src-ls); }
+.row.src-file { --src: var(--src-file); }
+.row.src-audit, .row.src-logstream, .row.src-file { border-left-color: var(--src); background: color-mix(in srgb, var(--src) var(--src-tint), transparent); }
+.row.src-audit:hover, .row.src-logstream:hover, .row.src-file:hover { background: color-mix(in srgb, var(--src) 13%, var(--row-hover)); }
+.src-badge {
+  justify-self: start; box-sizing: content-box; width: 6ch; padding: 0 4px; border-radius: 4px; text-align: center;
+  font-family: var(--log-font, var(--mono)); font-size: 10px; font-weight: 700; letter-spacing: .02em; line-height: 1.3;
+  color: var(--src); background: color-mix(in srgb, var(--src) 16%, transparent);
+  box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--src) 40%, transparent);
+}
+.row .raw {
+  margin-top: 2px; font-size: .85em; line-height: 1.35; color: var(--muted);
+  white-space: pre-wrap; word-break: break-all;
+}
+:root[data-density="compact"] .row:not(.open) .raw { display: none; }
+.src-help { margin-top: 10px !important; }
+.self-level { width: auto; justify-self: start; }
 /* Codes of the tags found in the message: grey badges, fixed size */
 .row .codes { white-space: nowrap; overflow: hidden; }
 .row .codes > span { display: inline-flex; gap: 3px; vertical-align: 1px; }
 .row .codes b, .tag-code {
-  min-width: 2.2ch; padding: 1px 4px; border-radius: 5px; text-align: center;
+  min-width: 2.2ch; padding: 0 4px; border-radius: 5px; text-align: center;
   /* same font as the severity badges (the log font) */
   font-family: var(--log-font, var(--mono)); font-size: 10.5px; font-weight: 700; letter-spacing: .03em;
-  line-height: 1.35; font-variant-numeric: tabular-nums;
+  line-height: 1.3; font-variant-numeric: tabular-nums;
   background: var(--code-bg); color: #0b0f17;
 }
 .row .codes b.more { background: none; box-shadow: inset 0 0 0 1px var(--code-bg); color: var(--muted); }
@@ -433,6 +504,22 @@ mark.hit { background: var(--hit); color: inherit; border-radius: 3px; padding:
   font-family: var(--mono); font-size: 12.5px; white-space: pre-wrap;
 }
 
+.auth-warn {
+  display: flex; align-items: center; gap: 10px;
+  margin: 6px 20px 0; padding: 6px 8px 6px 14px;
+  border: 1px solid color-mix(in srgb, var(--sev-warning) 45%, transparent);
+  background: color-mix(in srgb, var(--sev-warning) 12%, transparent);
+  color: var(--text); border-radius: var(--radius); font-size: 12.5px;
+}
+.auth-warn[hidden] { display: none; }
+.auth-warn span { flex: 1; }
+.auth-warn .icon-btn { width: 26px; height: 26px; flex: none; }
+.ro-note {
+  margin: 0 0 12px; padding: 8px 12px; border-radius: var(--radius); font-size: 12.5px;
+  background: color-mix(in srgb, var(--accent) 10%, transparent); color: var(--text);
+}
+.read-only .set-panel .set-section[inert] { opacity: .55; }
+
 .pill {
   position: fixed; top: 70px; left: 50%; transform: translateX(-50%); z-index: 30;
   border: 0; border-radius: 999px; padding: 7px 16px;
@@ -452,6 +539,7 @@ mark.hit { background: var(--hit); color: inherit; border-radius: 3px; padding:
 .conn.ok::before { color: var(--sev-info); }
 .conn.ko::before { color: var(--sev-err); }
 #stats .bad { color: var(--sev-err); }
+#stats .warn { color: var(--sev-warning); }
 /* "Back to top", at the right end of the status bar: never over a log row */
 .to-top { width: 24px; height: 24px; margin: -5px -6px -5px auto; flex: none; } /* no taller bar */
 .to-top svg { width: 16px; height: 16px; }
@@ -465,17 +553,30 @@ mark.hit { background: var(--hit); color: inherit; border-radius: 3px; padding:
 
 /* ---------- Settings dialog ---------- */
 dialog.settings {
-  width: min(900px, calc(100vw - 32px));
-  height: min(660px, calc(100vh - 64px)); max-height: none;
+  width: min(1280px, calc(100vw - 32px));
+  height: calc(100vh - 48px); max-height: 960px;
 }
 dialog.settings .dlg { display: flex; flex-direction: column; height: 100%; padding: 0; }
 dialog.settings .dlg > header { padding: 14px 16px 14px 22px; border-bottom: 1px solid var(--border); }
-.set-body { flex: 1; min-height: 0; display: grid; grid-template-columns: 200px minmax(0, 1fr); }
-.set-nav {
-  display: flex; flex-direction: column; gap: 2px;
-  padding: 12px 10px; border-right: 1px solid var(--border);
+.set-body { flex: 1; min-height: 0; display: grid; grid-template-columns: minmax(176px, max-content) minmax(0, 1fr); }
+.set-side {
+  display: flex; flex-direction: column; min-height: 0; overflow-y: auto;
+  border-right: 1px solid var(--border);
   background: color-mix(in srgb, var(--panel-2) 50%, transparent);
 }
+.set-nav { display: flex; flex-direction: column; gap: 2px; padding: 12px 10px; }
+/* Save / Cancel, under the section labels: Save takes the accent color while changes wait. */
+.set-actions {
+  display: flex; flex-wrap: wrap; gap: 6px; margin: 4px 10px 12px; padding-top: 12px;
+  border-top: 1px solid var(--border);
+}
+.set-actions .btn { flex: 1; justify-content: center; }
+.set-actions .btn.save { color: var(--muted); }
+.set-actions .btn svg { width: 16px; height: 16px; }
+.set-actions.dirty .btn.save { background: var(--accent); border-color: var(--accent); color: #fff; box-shadow: 0 0 0 3px var(--accent-soft); }
+.set-actions.dirty .btn.save:hover { filter: brightness(1.08); }
+.set-state { flex-basis: 100%; margin: 2px 2px 0; font-size: 12px; color: var(--muted); }
+.set-actions.dirty .set-state { color: var(--accent); font-weight: 550; }
 .set-nav button {
   display: flex; align-items: center; gap: 10px;
   height: 38px; padding: 0 12px; border: 0; border-radius: 9px;
@@ -485,17 +586,29 @@ dialog.settings .dlg > header { padding: 14px 16px 14px 22px; border-bottom: 1px
 .set-nav button:hover { background: var(--panel-2); color: var(--text); }
 .set-nav button[aria-selected="true"] { background: var(--accent-soft); color: var(--accent); }
 .set-nav svg { width: 18px; height: 18px; flex: none; }
-.set-panels { overflow-y: auto; padding: 2px 24px 22px; }
-.set-panel > .set-section:first-child { margin-top: 16px; }
+.set-panels { overflow-y: auto; padding: 16px 20px 20px; }
+/* Sections are cards laid out in columns when there is room; .span ones take the full width. */
+.set-panel { display: grid; grid-template-columns: repeat(auto-fit, minmax(380px, 1fr)); gap: 14px; align-items: start; grid-auto-flow: row dense; }
+.set-panel[hidden] { display: none; }
+.set-panel.wide { grid-template-columns: minmax(0, 1fr); }
+.set-panel > .set-section, .set-panel > .set-section + .set-section {
+  margin: 0; padding: 14px 16px; min-width: 0;
+  border: 1px solid var(--border); border-radius: 12px;
+  background: color-mix(in srgb, var(--panel-2) 35%, var(--panel));
+}
+.set-panel > .set-section.span { grid-column: 1 / -1; }
+.set-panel > .ro-note { grid-column: 1 / -1; margin: 0; }
+.sec-head { display: flex; align-items: baseline; justify-content: space-between; gap: 12px; }
 .hint { margin-top: 8px !important; }
 .lbl { font-size: 13px; font-weight: 550; }
 .set-panel .preview-list { margin: 14px 0 10px; pointer-events: none; }
 .preview-list .row {
   cursor: default;
-  grid-template-columns: max-content max-content minmax(0, max-content) minmax(0, 1fr);
-  grid-template-areas: "rcv sev host app" "msg msg msg msg";
+  grid-template-columns: max-content max-content max-content minmax(0, max-content) minmax(0, 1fr);
+  grid-template-areas: "src rcv sev host app" "msg msg msg msg msg";
   gap: 3px 10px;
 }
+.preview-list .row .src-badge { grid-area: src; }
 .preview-list .row time.rcv { grid-area: rcv; }
 .preview-list .row time.mt { display: none; }
 .preview-list .row .sev { grid-area: sev; }
@@ -531,6 +644,17 @@ select.field:focus { outline: 0; border-color: var(--accent); box-shadow: 0 0 0
   background: var(--panel-2); font-family: var(--mono); font-size: 12.5px;
 }
 .set-section.danger h3 { color: var(--sev-err); }
+.db-head { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; margin: 4px 0 6px; }
+.db-stats {
+  display: grid; grid-template-columns: max-content minmax(0, 1fr); gap: 5px 14px;
+  margin: 0 0 14px; padding: 10px 12px; border-radius: 8px; background: var(--panel-2); font-size: 12.5px;
+}
+.db-stats dt { color: var(--muted); }
+.db-stats dd { margin: 0; min-width: 0; overflow-wrap: anywhere; }
+.db-stats dd b { font-weight: 600; font-variant-numeric: tabular-nums; }
+.db-msg { grid-column: 1 / -1; color: var(--muted); }
+.db-msg.bad { color: var(--sev-err); }
+.link-btn:disabled { opacity: .5; cursor: default; text-decoration: none; }
 .purge-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 10px; }
 .btn.danger { color: var(--sev-err); border-color: color-mix(in srgb, var(--sev-err) 45%, var(--border)); }
 .btn.danger:hover:not(:disabled) { background: var(--sev-err); border-color: var(--sev-err); color: #fff; }
@@ -605,9 +729,19 @@ input.switch:checked::after { transform: translateX(14px); }
 input.switch:disabled { cursor: not-allowed; }
 input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
 
-.set-section footer { display: flex; flex-wrap: wrap; gap: 8px; justify-content: space-between; margin-top: 14px; }
-.tag-add { display: flex; flex-wrap: wrap; gap: 8px; }
-.tag-add select.field { width: auto; }
+/* Settings > Pattern: toolbar kept in view while the list scrolls, dense rows. */
+.tags-section { padding-top: 12px !important; }
+.tag-toolbar {
+  position: sticky; top: -16px; z-index: 2;
+  display: flex; flex-wrap: wrap; align-items: center; gap: 8px;
+  margin: 10px -16px 0; padding: 8px 16px;
+  background: color-mix(in srgb, var(--panel-2) 35%, var(--panel));
+  border-bottom: 1px solid var(--border);
+}
+.tag-toolbar .btn { height: 30px; }
+.tag-toolbar select.field { width: auto; height: 30px; }
+.tag-toolbar .dk-filter { flex: 1 1 220px; height: 30px; }
+.tag-toolbar #resetTags { margin-left: auto; }
 
 .seg { display: inline-flex; padding: 3px; gap: 3px; background: var(--panel-2); border: 1px solid var(--border); border-radius: 10px; }
 .seg button {
@@ -617,61 +751,103 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
 .seg button:hover { color: var(--text); }
 .seg button[aria-checked="true"] { background: var(--panel); color: var(--accent); box-shadow: 0 1px 3px rgba(0, 0, 0, .12); }
 
-.tag-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
+/* One wide column: long regular expressions stay readable. */
+.tag-list { display: flex; flex-direction: column; gap: 3px; margin-top: 10px; }
 .tag-row {
-  display: grid; align-items: center; gap: 8px 10px;
-  grid-template-columns: auto 38px minmax(8rem, 1fr) 7.5rem auto 36px;
-  padding: 8px 10px; border: 1px solid var(--border); border-radius: 10px;
-  background: var(--panel-2);
+  display: grid; align-items: center; gap: 4px 6px;
+  grid-template-columns: 2.4em 30px minmax(7rem, 1fr) 10rem auto 26px;
+  padding: 3px 4px 3px 6px; border: 1px solid var(--border); border-radius: 8px;
+  background: var(--panel);
 }
+.tag-row[hidden] { display: none; }
 .tag-row.off { opacity: .55; }
-.tag-row .tag-code { font-size: 12px; padding: 3px 6px; cursor: default; }
+.tag-row .tag-code { font-size: 11px; padding: 2px 4px; cursor: default; text-align: center; }
 .tag-row input[type="color"] {
-  width: 38px; height: 32px; padding: 0; border: 1px solid var(--border); border-radius: 8px;
+  width: 30px; height: 26px; padding: 0; border: 1px solid var(--border); border-radius: 6px;
   background: none; cursor: pointer;
 }
-.tag-row input[type="color"]::-webkit-color-swatch-wrapper { padding: 3px; }
+.tag-row input[type="color"]::-webkit-color-swatch-wrapper { padding: 2px; }
 .tag-row input[type="color"]::-webkit-color-swatch { border: 0; border-radius: 5px; }
 .tag-row input[type="text"] {
-  height: 32px; padding: 0 10px; min-width: 0;
-  border: 1px solid var(--border); border-radius: 8px; background: var(--panel);
-  font-family: var(--mono); font-size: 13px; outline: 0;
+  height: 26px; padding: 0 8px; min-width: 0;
+  border: 1px solid var(--border); border-radius: 6px; background: var(--panel);
+  font-family: var(--mono); font-size: 12.5px; outline: 0;
 }
 .tag-row input[type="text"]:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
-.tag-row .preview { font-family: var(--mono); font-size: 12.5px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; text-align: center; }
-.tag-row .opts { display: flex; gap: 4px; }
+.tag-row .preview { font-family: var(--mono); font-size: 12px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; text-align: center; }
+.tag-row .opts { display: flex; gap: 3px; }
 .opt {
-  display: inline-flex; align-items: center; height: 28px; padding: 0 8px;
-  border: 1px solid var(--border); border-radius: 7px; background: var(--panel);
-  font-size: 11.5px; font-weight: 600; color: var(--muted); cursor: pointer; user-select: none;
+  display: inline-flex; align-items: center; height: 24px; padding: 0 6px;
+  border: 1px solid var(--border); border-radius: 6px; background: var(--panel);
+  font-size: 11px; font-weight: 600; color: var(--muted); cursor: pointer; user-select: none;
 }
+.tag-row .icon-btn { width: 26px; height: 26px; border-radius: 6px; }
+.tag-row .icon-btn svg { width: 15px; height: 15px; }
 .opt input { display: none; }
 .opt:has(input:checked) { color: var(--accent); border-color: var(--accent); background: var(--accent-soft); }
+/* Log files (Settings > Sources) */
+.file-list { display: flex; flex-direction: column; gap: 4px; }
+.file-row {
+  display: grid; align-items: center; gap: 6px;
+  grid-template-columns: auto minmax(7rem, 1fr) minmax(10rem, 2fr) minmax(9rem, 1.4fr) minmax(6rem, .8fr) 26px;
+  padding: 6px 6px 6px 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--panel);
+}
+.file-row.off > input[type="text"], .file-row.off > select { opacity: .6; }
+.file-row input[type="text"] {
+  height: 28px; padding: 0 8px; min-width: 0;
+  border: 1px solid var(--border); border-radius: 6px; background: var(--panel); font-size: 12.5px; outline: 0;
+}
+.file-row input.mono { font-family: var(--mono); }
+.file-row input[type="text"]:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
+.file-row select.field { height: 28px; }
+.file-row .icon-btn { width: 26px; height: 26px; border-radius: 6px; }
+.file-row .icon-btn svg { width: 15px; height: 15px; }
+.file-row .fr-regex, .file-row .fr-status, .file-row .fr-sample { grid-column: 2 / -1; }
+.file-row .fr-sample {
+  margin: 0; font: 11.5px var(--mono); color: var(--muted);
+  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
+}
+.file-row .fr-sample[hidden] { display: none; }
+.file-row .fr-regex[hidden] { display: none; }
+.file-row .fr-status { margin: 0 !important; font-size: 12px; }
+.file-toolbar { margin-top: 10px; }
 .tag-row .err { grid-column: 1 / -1; color: var(--sev-err); font-size: 12px; }
 .tag-row .err:empty { display: none; }
 
 /* ---------- Mobile ---------- */
 @media (max-width: 760px) {
+  .file-row { grid-template-columns: auto minmax(0, 1fr) 26px; }
+  .file-row [data-del] { grid-column: 3; grid-row: 1; }
+  .file-row > [data-f="path"], .file-row > [data-f="format"], .file-row > [data-f="host"] { grid-column: 2 / -1; }
   body { font-size: 13.5px; }
   .topbar { flex-wrap: wrap; padding: 8px 16px; gap: 8px 10px; }
   .search { order: 3; flex-basis: 100%; max-width: none; }
   .live .lbl { display: none; }
+  .whoami .who-name { max-width: 12ch; }
   .filters { padding: 10px 16px 6px; }
   .filters select { flex: 1 1 calc(50% - 8px); max-width: none; min-width: 0; }
+  .view-mode { flex: 1 1 100%; }
+  .view-mode button { flex: 1; justify-content: center; }
+  /* Phones: the two dates on one line, the ◀ ▶ − buttons below */
+  .period { flex: 1 1 100%; flex-wrap: wrap; }
+  .period > span { display: none; }
+  .period input { flex: 1 1 calc(50% - 3px); min-width: 0; }
+  .period .btn.tool { order: 1; flex: 1; }
   .spacer { display: none; }
   #count { flex: 1 1 50%; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
   .histo { padding: 0 16px 6px; }
   .h-leg { display: none; }
-  .list, .error-banner, .table { margin-left: 16px; margin-right: 16px; }
+  .list, .error-banner, .auth-warn, .table { margin-left: 16px; margin-right: 16px; }
   /* Phones: no columns, two lines per log (layout below); the widths do not apply */
   .table { display: block; }
   .table .list { display: block; margin: 0; }
   .list-head { display: none; }
   .row, .table .row {
-    grid-template-columns: auto auto 1fr auto;
-    grid-template-areas: "rcv sev host codes" "msg msg msg msg";
+    grid-template-columns: auto auto auto 1fr auto;
+    grid-template-areas: "src rcv sev host codes" "msg msg msg msg msg";
     gap: 3px 8px; padding: 8px 12px 8px 10px;
   }
+  .row .src-badge { grid-area: src; }
   .row time.rcv { grid-area: rcv; }
   .row time.mt { display: none; } /* still shown in the details panel */
   .row .sev { grid-area: sev; }
@@ -685,22 +861,27 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
   .field-grid { grid-template-columns: 1fr; gap: 4px; }
   dialog.settings { height: calc(100vh - 24px); width: calc(100vw - 16px); }
   .set-body { grid-template-columns: 1fr; grid-template-rows: auto minmax(0, 1fr); }
-  .set-nav {
-    display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); padding: 6px;
-    border-right: 0; border-bottom: 1px solid var(--border);
-  }
+  .set-side { border-right: 0; border-bottom: 1px solid var(--border); overflow: visible; }
+  .set-nav { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); padding: 6px; }
+  .set-actions { margin: 0 6px 6px; padding-top: 6px; align-items: center; }
+  .set-actions .btn { flex: 0 0 auto; height: 30px; }
+  .set-state { flex: 1; flex-basis: auto; margin: 0; text-align: right; }
   .set-nav button {
     flex-direction: column; justify-content: center; height: auto; padding: 6px 2px; gap: 3px;
     font-size: 11.5px; text-align: center;
   }
-  .set-nav button span { max-width: 100%; overflow: hidden; text-overflow: ellipsis; }
-  .set-panels { padding: 0 16px 18px; }
+  .set-nav button span { max-width: 100%; white-space: normal; line-height: 1.15; overflow: hidden; text-overflow: ellipsis; }
+  .set-panels { padding: 12px 12px 18px; }
+  .set-panel { grid-template-columns: minmax(0, 1fr); gap: 10px; }
+  .set-panel > .set-section, .set-panel > .set-section + .set-section { padding: 12px; }
+  .tag-toolbar { position: static; margin: 10px -12px 0; padding: 8px 12px; }
+  .tag-toolbar #resetTags { margin-left: 0; }
   #sizeSwitch, #densitySwitch { display: flex; }
   #sizeSwitch button, #densitySwitch button { flex: 1; padding: 0 4px; white-space: nowrap; font-size: 12px; }
   :root[data-density="compact"] .row { padding-top: 3px; padding-bottom: 3px; }
   .field-grid select { margin-bottom: 6px; }
   .status { padding: 6px 16px; }
-  .tag-row { grid-template-columns: auto 38px 1fr 36px; }
+  .tag-row { grid-template-columns: auto 30px 1fr 26px; }
   .tag-row .preview { display: none; }
   .tag-row .opts { grid-column: 1 / -1; grid-row: 2; flex-wrap: wrap; }
   .tag-row [data-del] { grid-column: 4; grid-row: 1; }