Default tags: keep warning and error, move ok to the Log levels preset

Existing tags.json files are unchanged; only new installs and "Restore
default tags" get the shorter list.

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

.env.example

@@ -12,6 +12,11 @@ AUTH_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

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

@@ -78,8 +78,8 @@ par exemple `error AND host:web-01`, `app:~"ssh|nginx"` ou `* | stats by (host)
 Le direct est désactivé dans ce mode.
 
 Chaque ligne affiche, de gauche à droite : l'**heure de réception** (horloge du serveur),
-l'horodatage trouvé dans le message lui-même (`msg_time`), la sévérité, l'hôte, l'application
-et le message. Un clic sur un hôte ou une application filtre dessus.
+l'horodatage trouvé dans le message lui-même (`msg_time`), la sévérité, l'hôte, l'application,
+les codes des tags trouvés et le message. Un clic sur un hôte ou une application filtre dessus.
 
 Les logs sont indexés, recherchés et triés par **heure de réception** : les équipements dont
 l'horloge est fausse (par exemple des points d'accès dont le NTP échoue) apparaissent quand même
@@ -225,20 +225,38 @@ couleur, est mémorisé par navigateur.
   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 : 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
+  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**
   - *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) et police :
-    la police monospace du système, ou l'une des 12 polices libres conçues pour le texte dense
+  - *Affichage des logs* : taille du texte (très petite, petite, moyenne, grande), densité
+    (normale, ou compacte pour afficher environ 50 % de lignes en plus à l'écran) et police :
+    la police monospace du système, l'une des 3 polices étroites intégrées, servies par
+    LogStream lui-même et utilisables hors ligne (Inconsolata Condensed, la plus étroite,
+    Iosevka et Ubuntu Mono), ou l'une des 11 polices libres conçues pour le texte dense
     (JetBrains Mono, Fira Code, Source Code Pro, IBM Plex Mono, Cascadia Code, Roboto Mono,
-    Ubuntu Mono, Inconsolata, Red Hat Mono, Noto Sans Mono, Victor Mono, DM Mono). Elles sont
+    Inconsolata, Red Hat Mono, Noto Sans Mono, Victor Mono, DM Mono). Ces 11 polices sont
     chargées par le navigateur depuis [Bunny Fonts](https://fonts.bunny.net), un service
     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.
+    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
   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
@@ -334,6 +352,7 @@ résolutions.
 | `DNS_SERVER` | vide | serveur DNS pour les résolutions inverses (`ip` ou `ip:port`) |
 | `ALLOW_PURGE` | `true` | autoriser « Supprimer tous les logs » dans les Paramètres |
 | `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 |
@@ -400,6 +419,7 @@ Pour mettre à jour l'une d'elles :
 | `syslogserver.go` | écoutes syslog ouvertes et fermées depuis Paramètres > Sources |
 | `hostlogs.go`, `journal.go` | logs système de l'hôte : lecteur du journal systemd (sans `journalctl`) et suivi de `/var/log` |
 | `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

@@ -72,7 +72,7 @@ message, host and app. Words are combined with AND.
 The live view is disabled in this mode.
 
 Each row shows, from left to right: the **reception time** (server clock), the timestamp
-found in the message itself (`msg_time`), severity, host, app and message. Click a host or an
+found in the message itself (`msg_time`), severity, host, app, codes of the tags found and message. Click a host or an
 app to filter on it.
 
 Logs are indexed, searched and sorted by **reception time**: devices with a wrong clock
@@ -205,17 +205,34 @@ remembered per browser.
   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.
+  `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
+  each message; it has room for 3, beyond that it shows 2 and `+N`, and the tooltip lists them
+  all.
 - **Interface**
   - *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) and font: the system monospace
-    font, or one of 12 free fonts made for dense text (JetBrains Mono, Fira Code, Source
-    Code Pro, IBM Plex Mono, Cascadia Code, Roboto Mono, Ubuntu Mono, Inconsolata, Red Hat
-    Mono, Noto Sans Mono, Victor Mono, DM Mono). They are loaded by the browser from
+  - *Log display*: font size (tiny, small, medium, large), density (normal, or compact to
+    fit about 50% more lines on screen) and font: the system monospace font, one of 3 narrow
+    built-in fonts served by LogStream itself, which work offline (Inconsolata Condensed, the
+    narrowest, Iosevka and Ubuntu Mono), or one of 11 free fonts made for dense text (JetBrains
+    Mono, Fira Code, Source Code Pro, IBM Plex Mono, Cascadia Code, Roboto Mono, Inconsolata,
+    Red Hat Mono, Noto Sans Mono, Victor Mono, DM Mono). These 11 are loaded by the browser from
     [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.
+    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
   `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.
@@ -304,6 +321,7 @@ are only known by your router or a local DNS (Pi-hole, AdGuard, Unbound…), set
 | `DNS_SERVER` | empty | DNS server for reverse lookups (`ip` or `ip:port`) |
 | `ALLOW_PURGE` | `true` | allow "Delete all logs" in Settings |
 | `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 |
@@ -367,6 +385,7 @@ To update one of them:
 | `syslogserver.go` | syslog listeners opened and closed from Settings > Sources |
 | `hostlogs.go`, `journal.go` | host system logs: systemd journal reader (no `journalctl`) and `/var/log` follower |
 | `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

@@ -16,6 +16,7 @@ type API struct {
 	store      *Store
 	hub        *Hub
 	tags       *TagStore
+	presets    string // presets file, built-in presets when missing
 	rdns       *ReverseDNS
 	allowPurge bool
 	exportMax  int
@@ -34,6 +35,7 @@ func (a *API) Routes(mux *http.ServeMux) {
 	mux.HandleFunc("GET /api/tags", a.listTags)
 	mux.HandleFunc("POST /api/tags", a.createTag)
 	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)
@@ -316,6 +318,10 @@ 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)

auth.go

@@ -252,7 +252,7 @@ func (o *OIDC) handleCallback(w http.ResponseWriter, r *http.Request) {
 	var ls loginState
 	c, err := r.Cookie(loginCookie + state)
 	if state == "" || err != nil || !verifyCookie(o.key, c.Value, &ls) || time.Now().Unix() > ls.Exp {
-		http.Error(w, "login expired or started in another browser: open logstream again", http.StatusBadRequest)
+		http.Error(w, "login expired or started in another browser: open LogStream again", http.StatusBadRequest)
 		return
 	}
 	http.SetCookie(w, &http.Cookie{Name: loginCookie + state, Path: "/", MaxAge: -1, HttpOnly: true, Secure: o.secure})
@@ -260,7 +260,7 @@ func (o *OIDC) handleCallback(w http.ResponseWriter, r *http.Request) {
 	user, 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)
+		http.Error(w, "login failed, see the LogStream logs", http.StatusForbidden)
 		return
 	}
 	log.Printf("oidc: %s logged in", user)

docker-compose.yml

@@ -18,6 +18,7 @@ services:
       AUTH_USER: ${AUTH_USER:-}   # vide = pas d'authentification, on delegue ca au reverse proxy traefik
       AUTH_PASS: ${AUTH_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:-}
@@ -41,6 +42,8 @@ services:
       - /run/log/journal:/host/run/log/journal:ro     # journal systemd volatile
       # 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
 

docs/presets.fr.md

@@ -0,0 +1,114 @@
+[English](presets.md) · **Français**
+
+# Préréglages de tags de couleur
+
+Dans **Paramètres › Filtres**, 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 › Filters**, 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)`.

main.go

@@ -143,7 +143,8 @@ 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 {

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)
+		}
+	}
+}

tags.go

@@ -16,7 +16,9 @@ import (
 // Tag highlights a keyword in displayed messages.
 type Tag struct {
 	ID            string `json:"id"`
+	Code          string `json:"code"` // two digits, shown on matching log lines
 	Pattern       string `json:"pattern"`
+	Label         string `json:"label,omitempty"` // shown instead of the pattern (presets)
 	Color         string `json:"color"`
 	WholeWord     bool   `json:"wholeWord"`
 	CaseSensitive bool   `json:"caseSensitive"`
@@ -26,12 +28,46 @@ type Tag struct {
 
 func defaultTags() []Tag {
 	return []Tag{
-		{ID: "warning", Pattern: "warning", Color: "#fdba74", WholeWord: true, Enabled: true},
-		{ID: "error", Pattern: "error", Color: "#fca5a5", WholeWord: true, Enabled: true},
-		{ID: "ok", Pattern: "ok", Color: "#86efac", WholeWord: true, Enabled: true},
+		{ID: "warning", Code: "01", Pattern: "warning", Color: "#fdba74", WholeWord: true, Enabled: true},
+		{ID: "error", Code: "02", Pattern: "error", Color: "#fca5a5", WholeWord: true, Enabled: true},
 	}
 }
 
+var codeRe = regexp.MustCompile(`^[0-9]{2}$`)
+
+// freeCode returns the lowest code from 01 to 99 not used by tags, or "" when
+// all are taken. A code stays with its tag until the tag is deleted.
+func freeCode(tags []Tag) string {
+	used := map[string]bool{}
+	for _, t := range tags {
+		used[t.Code] = true
+	}
+	for n := 1; n <= 99; n++ {
+		if c := fmt.Sprintf("%02d", n); !used[c] {
+			return c
+		}
+	}
+	return ""
+}
+
+// assignCodes gives a code to the tags that have none (files written before
+// codes existed) or share one with an earlier tag.
+func assignCodes(tags []Tag) bool {
+	changed := false
+	seen := map[string]bool{}
+	for i := range tags {
+		if codeRe.MatchString(tags[i].Code) && !seen[tags[i].Code] {
+			seen[tags[i].Code] = true
+			continue
+		}
+		tags[i].Code = ""
+		tags[i].Code = freeCode(tags)
+		seen[tags[i].Code] = true
+		changed = true
+	}
+	return changed
+}
+
 // Colors of the default tags in earlier versions: still unchanged, they are
 // switched to the new pastel defaults when the file is loaded.
 var oldDefaultColors = map[string]string{"warning": "#f59e0b", "error": "#ef4444", "ok": "#22c55e"}
@@ -67,11 +103,13 @@ func (e *codedError) Error() string {
 
 var (
 	errTagNotFound = &codedError{code: "tag_not_found", msg: "tag not found"}
+	errTooManyTags = &codedError{code: "too_many_tags", msg: "too many tags (99 at most)"}
 	colorRe        = regexp.MustCompile(`^#[0-9a-fA-F]{6}$`)
 )
 
 func (t *Tag) validate() error {
 	t.Pattern = strings.TrimSpace(t.Pattern)
+	t.Label = strings.TrimSpace(t.Label)
 	if t.Pattern == "" {
 		return &codedError{code: "pattern_required", msg: "the keyword is required"}
 	}
@@ -106,7 +144,7 @@ func LoadTagStore(path string) (*TagStore, error) {
 	if err := json.Unmarshal(b, &s.tags); err != nil {
 		return nil, fmt.Errorf("%s: %w", path, err)
 	}
-	if migrateDefaultColors(s.tags) {
+	if c1, c2 := migrateDefaultColors(s.tags), assignCodes(s.tags); c1 || c2 {
 		if err := s.save(); err != nil {
 			return nil, err
 		}
@@ -143,6 +181,9 @@ func (s *TagStore) Create(t Tag) (Tag, error) {
 	t.ID = newID()
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	if t.Code = freeCode(s.tags); t.Code == "" {
+		return t, errTooManyTags
+	}
 	s.tags = append(s.tags, t)
 	return t, s.save()
 }
@@ -156,6 +197,7 @@ func (s *TagStore) Update(id string, t Tag) (Tag, error) {
 	defer s.mu.Unlock()
 	for i := range s.tags {
 		if s.tags[i].ID == id {
+			t.Code = s.tags[i].Code // assigned by the server, never changed
 			s.tags[i] = t
 			return t, s.save()
 		}

tags_test.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"slices"
+	"testing"
+)
+
+func TestTagCodes(t *testing.T) {
+	path := filepath.Join(t.TempDir(), "tags.json")
+	// File written before codes existed, with a duplicate code.
+	old := `[{"id":"a","pattern":"x","color":"#000000"},{"id":"b","code":"07","pattern":"y","color":"#000000"},{"id":"c","code":"07","pattern":"z","color":"#000000"}]`
+	if err := os.WriteFile(path, []byte(old), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	s, err := LoadTagStore(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	got := []string{}
+	for _, tg := range s.List() {
+		got = append(got, tg.Code)
+	}
+	if want := []string{"01", "07", "02"}; !slices.Equal(got, want) {
+		t.Fatalf("migrated codes = %v, want %v", got, want)
+	}
+
+	n, err := s.Create(Tag{Pattern: "w", Color: "#000000"})
+	if err != nil || n.Code != "03" {
+		t.Fatalf("Create code = %q, %v; want 03", n.Code, err)
+	}
+	// The client cannot change a code.
+	u, err := s.Update("b", Tag{Code: "42", Pattern: "y2", Color: "#000000"})
+	if err != nil || u.Code != "07" {
+		t.Fatalf("Update code = %q, %v; want 07", u.Code, err)
+	}
+	// A deleted tag frees its code; the others keep theirs.
+	if err := s.Delete("a"); err != nil {
+		t.Fatal(err)
+	}
+	if n, _ := s.Create(Tag{Pattern: "v", Color: "#000000"}); n.Code != "01" {
+		t.Fatalf("code after delete = %q, want 01", n.Code)
+	}
+
+	// Codes are saved in the file.
+	s2, err := LoadTagStore(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got := s2.List()[0].Code; got != "07" {
+		t.Fatalf("reloaded code = %q, want 07", got)
+	}
+}

web/app.js

@@ -47,12 +47,16 @@ const I18N = {
     colorAria: 'Color', keyword: 'keyword', preview: 'preview', del: 'Delete', noTags: 'No tags.',
     newTag: 'new',
     confirmDelete: (p) => `Delete tag "${p}"?`,
-    confirmReset: 'Replace all tags with the defaults (warning, error, ok)?',
+    confirmReset: 'Replace all tags with the defaults (warning, error)?',
+    presetAria: 'Add a preset', presetPick: '+ Preset…',
+    presetAdded: (n) => (n ? `${n} tag(s) added` : 'These tags are already in the list'),
+    presetsFileErr: (f) => `Invalid presets file ${f}, built-in presets used: `,
     tagsLoadErr: 'Tags: ',
     err_pattern_required: 'The keyword is required',
     err_invalid_color: 'Invalid color (expected #rrggbb)',
     err_invalid_regex: 'Invalid regular expression',
     err_tag_not_found: 'Tag not found',
+    err_too_many_tags: 'Too many tags (99 at most)',
     err_live_logsql: 'Live view is not available in LogsQL mode',
     dateTime: 'Date & time',
     tzLabel: 'Time zone',
@@ -71,7 +75,7 @@ const I18N = {
     srcHost: 'Host system',
     hostTitle: 'Host system logs',
     hostEnabled: 'Collect the system logs of this machine',
-    hostOff: 'Off: the system logs of the machine hosting Logstream are not collected.',
+    hostOff: 'Off: the system logs of the machine hosting LogStream are not collected.',
     hostWaiting: 'Starting…',
     hostJournal: ({ n, r }) => `Reading the systemd journal (${n} files): ${r} entries since startup.`,
     hostFiles: ({ n, r }) => `Following ${n} files of /var/log: ${r} lines since startup.`,
@@ -98,8 +102,8 @@ const I18N = {
     dockerLegend: 'Colored: followed · grey: not followed · dashed: stopped · the color identifies the compose project. Click a label to switch it.',
     dockerNoMatch: 'No container',
     stFollowing: 'followed', stSelected: 'followed when running', stIgnored: 'not followed', stStopped: 'stopped',
-    stLocked: 'excluded', stLockedTitle: 'Logstream itself, or label logstream.exclude=true',
-    dockerHelp: 'Logs are read through docker-socket-proxy, a read-only gateway: Logstream can list containers and read their logs, nothing else. Choices apply per compose service (or container name), so they survive container re-creations.',
+    stLocked: 'excluded', stLockedTitle: 'LogStream itself, or label logstream.exclude=true',
+    dockerHelp: 'Logs are read through docker-socket-proxy, a read-only gateway: LogStream can list containers and read their logs, nothing else. Choices apply per compose service (or container name), so they survive container re-creations.',
     fContainer: 'container', fContainerId: 'container ID', fImage: 'image', fProject: 'compose project',
     fService: 'compose service', fStream: 'stream', fSourceType: 'source',
     fUnit: 'systemd unit', fLogFile: 'log file',
@@ -113,8 +117,9 @@ const I18N = {
     themeHelp: 'System follows the light/dark preference of your computer or phone.',
     logDisplay: 'Log display', fontSize: 'Font size',
     sizeTiny: 'Tiny', sizeSmall: 'Small', sizeMedium: 'Medium', sizeLarge: 'Large',
-    fontLabel: 'Font', fontSystem: 'System monospace (no download)',
-    fontHelp: 'Free fonts (SIL Open Font License) loaded by your browser from Bunny Fonts, a privacy-friendly European font service. Without internet access, the system font is used.',
+    density: 'Density', densityNormal: 'Normal', densityCompact: 'Compact',
+    fontLabel: 'Font', fontSystem: 'System monospace (no download)', fontBuiltin: 'built in, narrow',
+    fontHelp: 'Free fonts. The built-in ones (Inconsolata Condensed, the narrowest, Iosevka and Ubuntu Mono) are served by LogStream itself and work offline; they are narrow, so more text fits on each line. The others are loaded by your browser from Bunny Fonts, a privacy-friendly European font service; without internet access, the system font is used.',
     previewMsgs: ['error: link down on eth1, carrier lost', 'warning: disk /dev/sda temperature 58°C', 'backup finished: ok (12.4 GB in 00:14:32)'],
     dangerZone: 'Danger zone',
     purgeHelp: 'Permanently delete every stored log to start from scratch. Color tags and settings are kept.',
@@ -142,7 +147,9 @@ const I18N = {
     hCappedTitle: 'The chosen division would exceed 300 intervals over this range: it has been enlarged.',
     hUnzoom: '× Reset zoom', unitDay: 'd',
     toTop: 'Back to top',
-    colRcv: 'Received', colMt: 'Message time', colSev: 'Severity', colHost: 'Host', colApp: 'App', colMsg: 'Message',
+    colRcv: 'Received', colMt: 'Message time', colSev: 'Severity', colHost: 'Host', colApp: 'App', colCodes: 'Filters', colMsg: 'Message',
+    codesTitle: 'Codes of the color tags found in the message',
+    tagCodeTitle: 'Code shown on the log lines this tag matches',
     colGrip: 'Drag to resize, double-click for the automatic width',
     resetCols: 'Reset column widths', colsReset: 'Column widths reset',
     colsHelp: 'Drag the edge of a column header in the log list to resize it (remembered by this browser).',
@@ -191,12 +198,16 @@ const I18N = {
     colorAria: 'Couleur', keyword: 'mot-clé', preview: 'aperçu', del: 'Supprimer', noTags: 'Aucun tag.',
     newTag: 'nouveau',
     confirmDelete: (p) => `Supprimer le tag « ${p} » ?`,
-    confirmReset: 'Remplacer tous les tags par les tags par défaut (warning, error, ok) ?',
+    confirmReset: 'Remplacer tous les tags par les tags par défaut (warning, error) ?',
+    presetAria: 'Ajouter un préréglage', presetPick: '+ Préréglage…',
+    presetAdded: (n) => (n ? `${n} tag(s) ajouté(s)` : 'Ces tags sont déjà dans la liste'),
+    presetsFileErr: (f) => `Fichier de préréglages ${f} invalide, préréglages intégrés utilisés : `,
     tagsLoadErr: 'Tags : ',
     err_pattern_required: 'Le mot-clé est obligatoire',
     err_invalid_color: 'Couleur invalide (format #rrggbb attendu)',
     err_invalid_regex: 'Expression régulière invalide',
     err_tag_not_found: 'Tag introuvable',
+    err_too_many_tags: 'Trop de tags (99 au maximum)',
     err_live_logsql: 'Le direct n\'est pas disponible en mode LogsQL',
     dateTime: 'Date et heure',
     tzLabel: 'Fuseau horaire',
@@ -215,7 +226,7 @@ const I18N = {
     srcHost: 'Système hôte',
     hostTitle: 'Logs système de l\'hôte',
     hostEnabled: 'Collecter les logs système de cette machine',
-    hostOff: 'Désactivé : les logs système de la machine qui héberge Logstream ne sont pas collectés.',
+    hostOff: 'Désactivé : les logs système de la machine qui héberge LogStream ne sont pas collectés.',
     hostWaiting: 'Démarrage…',
     hostJournal: ({ n, r }) => `Lecture du journal systemd (${n} fichiers) : ${r} entrées depuis le démarrage.`,
     hostFiles: ({ n, r }) => `Suivi de ${n} fichiers de /var/log : ${r} lignes depuis le démarrage.`,
@@ -242,8 +253,8 @@ const I18N = {
     dockerLegend: 'En couleur : suivis · en gris : non suivis · pointillés : arrêtés · la couleur identifie le projet compose. Cliquez sur une étiquette pour la basculer.',
     dockerNoMatch: 'Aucun conteneur',
     stFollowing: 'suivi', stSelected: 'suivi dès qu\'il tourne', stIgnored: 'non suivi', stStopped: 'arrêté',
-    stLocked: 'exclu', stLockedTitle: 'Logstream lui-même, ou étiquette logstream.exclude=true',
-    dockerHelp: 'Les logs sont lus via docker-socket-proxy, une passerelle en lecture seule : Logstream peut lister les conteneurs et lire leurs logs, rien d\'autre. Les choix s\'appliquent par service compose (ou nom de conteneur), ils survivent donc à la recréation des conteneurs.',
+    stLocked: 'exclu', stLockedTitle: 'LogStream lui-même, ou étiquette logstream.exclude=true',
+    dockerHelp: 'Les logs sont lus via docker-socket-proxy, une passerelle en lecture seule : LogStream peut lister les conteneurs et lire leurs logs, rien d\'autre. Les choix s\'appliquent par service compose (ou nom de conteneur), ils survivent donc à la recréation des conteneurs.',
     fContainer: 'conteneur', fContainerId: 'ID du conteneur', fImage: 'image', fProject: 'projet compose',
     fService: 'service compose', fStream: 'flux', fSourceType: 'source',
     fUnit: 'unité systemd', fLogFile: 'fichier de log',
@@ -257,8 +268,9 @@ const I18N = {
     themeHelp: 'Système suit la préférence clair/sombre de votre ordinateur ou de votre téléphone.',
     logDisplay: 'Affichage des logs', fontSize: 'Taille du texte',
     sizeTiny: 'Très petite', sizeSmall: 'Petite', sizeMedium: 'Moyenne', sizeLarge: 'Grande',
-    fontLabel: 'Police', fontSystem: 'Monospace du système (aucun téléchargement)',
-    fontHelp: 'Polices libres (licence SIL Open Font) chargées par votre navigateur depuis Bunny Fonts, un service européen respectueux de la vie privée. Sans accès à internet, la police du système est utilisée.',
+    density: 'Densité', densityNormal: 'Normale', densityCompact: 'Compacte',
+    fontLabel: 'Police', fontSystem: 'Monospace du système (aucun téléchargement)', fontBuiltin: 'intégrée, étroite',
+    fontHelp: 'Polices libres. Les polices intégrées (Inconsolata Condensed, la plus étroite, Iosevka et Ubuntu Mono) sont servies par LogStream lui-même et fonctionnent hors ligne ; elles sont étroites, donc chaque ligne affiche plus de texte. Les autres sont chargées par votre navigateur depuis Bunny Fonts, un service européen respectueux de la vie privée ; sans accès à internet, la police du système est utilisée.',
     previewMsgs: ['error: link down on eth1, carrier lost', 'warning: disk /dev/sda temperature 58°C', 'backup finished: ok (12.4 GB in 00:14:32)'],
     dangerZone: 'Zone de danger',
     purgeHelp: 'Supprime définitivement tous les logs stockés pour repartir de zéro. Les tags de couleur et les réglages sont conservés.',
@@ -286,7 +298,9 @@ const I18N = {
     hCappedTitle: 'La division choisie dépasserait 300 intervalles sur cette plage : elle a été élargie.',
     hUnzoom: '× Annuler le zoom', unitDay: 'j',
     toTop: 'Revenir en haut',
-    colRcv: 'Réception', colMt: 'Heure message', colSev: 'Sévérité', colHost: 'Hôte', colApp: 'App', colMsg: 'Message',
+    colRcv: 'Réception', colMt: 'Heure message', colSev: 'Sévérité', colHost: 'Hôte', colApp: 'App', colCodes: 'Filtres', colMsg: 'Message',
+    codesTitle: 'Codes des tags de couleur trouvés dans le message',
+    tagCodeTitle: 'Code affiché sur les lignes de log où ce tag est trouvé',
     colGrip: 'Glisser pour redimensionner, double-clic pour la largeur automatique',
     resetCols: 'Réinitialiser les colonnes', colsReset: 'Largeurs de colonnes réinitialisées',
     colsHelp: 'Glissez le bord d\'un en-tête de colonne de la liste pour la redimensionner (mémorisé par ce navigateur).',
@@ -437,6 +451,7 @@ const state = {
   rows: [],          // displayed records, newest first
   pending: [],       // live messages received while scrolled down
   tags: [],
+  presets: [],       // preset groups from /api/presets
   matchers: [],      // compiled tags + search terms
   mode: store.get('mode', 'simple'),
   live: store.get('live', '1') === '1',
@@ -475,6 +490,7 @@ function setLang(next) {
   renderHisto();
   renderStats();
   renderTagList();
+  renderPresets();
   renderTimeSettings();
   renderPurge();
   renderInterface();
@@ -519,16 +535,19 @@ $('#themeSwitch').addEventListener('click', (ev) => {
 
 /* ================= Log font and size ================= */
 
-// Free monospace fonts, served by Bunny Fonts (https://fonts.bunny.net).
+// Free monospace fonts, served by Bunny Fonts (https://fonts.bunny.net), except the
+// built-in ones (web/fonts, declared in style.css), which also work offline.
 const LOG_FONTS = [
   { id: 'system' },
+  { id: 'inconsolata-condensed', family: 'Inconsolata Condensed', builtin: true },
+  { id: 'iosevka', family: 'Iosevka', builtin: true },
+  { id: 'ubuntu-mono', family: 'Ubuntu Mono', builtin: true },
   { id: 'jetbrains-mono', family: 'JetBrains Mono' },
   { id: 'fira-code', family: 'Fira Code' },
   { id: 'source-code-pro', family: 'Source Code Pro' },
   { id: 'ibm-plex-mono', family: 'IBM Plex Mono' },
   { id: 'cascadia-code', family: 'Cascadia Code' },
   { id: 'roboto-mono', family: 'Roboto Mono' },
-  { id: 'ubuntu-mono', family: 'Ubuntu Mono' },
   { id: 'inconsolata', family: 'Inconsolata' },
   { id: 'red-hat-mono', family: 'Red Hat Mono' },
   { id: 'noto-sans-mono', family: 'Noto Sans Mono' },
@@ -536,7 +555,8 @@ const LOG_FONTS = [
   { id: 'dm-mono', family: 'DM Mono', weights: '400,500' },
 ];
 const LOG_SIZES = { tiny: '10.5px', small: '11.5px', medium: '12.5px', large: '14px' };
-const ui = { font: 'system', size: 'medium' };
+const LOG_DENSITIES = ['normal', 'compact'];
+const ui = { font: 'system', size: 'medium', density: 'normal' };
 
 function applyLogFont(id) {
   const f = LOG_FONTS.find((x) => x.id === id) || LOG_FONTS[0];
@@ -546,6 +566,10 @@ function applyLogFont(id) {
     root.removeProperty('--log-font');
     return;
   }
+  if (f.builtin) {
+    root.setProperty('--log-font', `'${f.family}', var(--mono)`);
+    return;
+  }
   const href = `https://fonts.bunny.net/css?family=${f.id}:${f.weights || '400,700'}&display=swap`;
   let link = document.getElementById('logFontCss');
   if (!link) {
@@ -561,13 +585,22 @@ function applyLogSize(id) {
   document.documentElement.style.setProperty('--log-size', LOG_SIZES[ui.size]);
 }
 
+function applyLogDensity(id) {
+  ui.density = LOG_DENSITIES.includes(id) ? id : 'normal';
+  document.documentElement.dataset.density = ui.density;
+}
+
 function renderInterface() {
   renderThemeSwitch();
   for (const b of document.querySelectorAll('#sizeSwitch [data-size]')) {
     b.setAttribute('aria-checked', String(b.dataset.size === ui.size));
   }
+  for (const b of document.querySelectorAll('#densitySwitch [data-density]')) {
+    b.setAttribute('aria-checked', String(b.dataset.density === ui.density));
+  }
   const sel = $('#fontSelect');
-  sel.innerHTML = LOG_FONTS.map((f) => `<option value="${f.id}">${esc(f.family || t('fontSystem'))}</option>`).join('');
+  const fontName = (f) => (!f.family ? t('fontSystem') : f.builtin ? `${f.family} (${t('fontBuiltin')})` : f.family);
+  sel.innerHTML = LOG_FONTS.map((f) => `<option value="${f.id}">${esc(fontName(f))}</option>`).join('');
   sel.value = ui.font;
   renderFontPreview();
   renderHistoSettings();
@@ -591,6 +624,13 @@ $('#sizeSwitch').addEventListener('click', (ev) => {
   store.set('logSize', ui.size);
   renderInterface();
 });
+$('#densitySwitch').addEventListener('click', (ev) => {
+  const b = ev.target.closest('[data-density]');
+  if (!b) return;
+  applyLogDensity(b.dataset.density);
+  store.set('logDensity', ui.density);
+  renderInterface();
+});
 $('#fontSelect').addEventListener('change', (ev) => {
   applyLogFont(ev.target.value);
   store.set('logFont', ui.font);
@@ -681,7 +721,11 @@ function compileMatchers() {
     let src = tag.regex ? tag.pattern : escapeRe(tag.pattern);
     if (tag.wholeWord) src = `(?<![\\p{L}\\p{N}_])(?:${src})(?![\\p{L}\\p{N}_])`;
     try {
-      out.push({ re: new RegExp(src, 'gu' + (tag.caseSensitive ? '' : 'i')), html: `<mark class="tag" style="${tagStyle(tag.color)}">` });
+      // A regex may name a group "hl" to color only that part of the match.
+      const hl = tag.regex && /\(\?P?<hl>/.test(tag.pattern);
+      if (hl) src = src.replace(/\(\?P<hl>/g, '(?<hl>');
+      out.push({ re: new RegExp(src, 'gu' + (hl ? 'd' : '') + (tag.caseSensitive ? '' : 'i')), html: `<mark class="tag" style="${tagStyle(tag.color)}">`,
+        code: tag.code, name: tag.label || tag.pattern });
     } catch (e) {
       console.warn('Tag skipped (invalid pattern):', tag.pattern, e.message);
     }
@@ -706,6 +750,8 @@ function highlight(text) {
     let x;
     while ((x = m.re.exec(text)) !== null) {
       if (x[0] === '') { m.re.lastIndex++; continue; }
+      const g = x.indices?.groups?.hl;
+      if (g) { if (g[1] > g[0]) spans.push({ s: g[0], e: g[1], prio, html: m.html }); continue; }
       spans.push({ s: x.index, e: x.index + x[0].length, prio, html: m.html });
     }
   });
@@ -721,6 +767,30 @@ function highlight(text) {
   return out + esc(text.slice(pos));
 }
 
+// Badges with the codes of the tags found in a message, in list order. The
+// column has room for 3: beyond that, 2 badges and "+N" (all in the tooltip).
+function codesHTML(text) {
+  text = String(text ?? '');
+  const found = [];
+  for (const m of state.matchers) {
+    if (!m.code || !text) continue;
+    m.re.lastIndex = 0;
+    let x;
+    while ((x = m.re.exec(text)) !== null) {
+      if (x[0] === '') { m.re.lastIndex++; continue; }
+      const g = x.indices?.groups?.hl;
+      if (!x.indices?.groups || g) { found.push(m); break; }
+    }
+  }
+  if (!found.length) return '';
+  const shown = found.length > 3 ? found.slice(0, 2) : found;
+  const title = found.map((m) => `${m.code} ${m.name}`).join('\n');
+  return `<span title="${esc(title)}">`
+    + shown.map((m) => `<b>${esc(m.code)}</b>`).join('')
+    + (found.length > 3 ? `<b class="more">+${found.length - 2}</b>` : '')
+    + '</span>';
+}
+
 /* ================= List rendering ================= */
 
 const SEV_CLASS = { emerg: 'crit', alert: 'crit', crit: 'crit', err: 'err', warning: 'warning', notice: 'notice', info: 'info', debug: 'debug' };
@@ -746,6 +816,7 @@ function rowHTML(r, isNew) {
     + (r.app
       ? `<span class="app${r.source_type === 'docker' ? ' proj' : ''}" data-act="app"${r.source_type === 'docker' ? ` style="--h:${hueOf(r.compose_project || r.container || r.app)}"` : ''} title="${esc((r.compose_project ? r.compose_project + '/' : '') + (r.container ? r.container + ' · ' : '') + r.app + ' · ' + t('clickApp'))}">${r.source_type === 'docker' ? DOCKER_ICON : ''}${esc(r.app)}</span>`
       : '<span class="app"></span>')
+    + `<span class="codes">${codesHTML(r._msg)}</span>`
     + `<div class="msg">${highlight(r._msg)}</div>`
     + '</article>';
 }
@@ -812,7 +883,9 @@ function renderList() {
 function rehighlight() {
   for (const row of list.children) {
     const r = recOf.get(row);
-    if (r) row.querySelector('.msg').innerHTML = highlight(r._msg);
+    if (!r) continue;
+    row.querySelector('.msg').innerHTML = highlight(r._msg);
+    row.querySelector('.codes').innerHTML = codesHTML(r._msg);
   }
 }
 
@@ -1978,6 +2051,25 @@ $('#purgeBtn').addEventListener('click', async () => {
 
 const PALETTE = ['#6366f1', '#0ea5e9', '#14b8a6', '#a855f7', '#ec4899', '#eab308', '#64748b', '#f97316'];
 
+// Ready-made tags, from the presets file (or the built-in presets.json):
+// see docs/presets.md. A text is a string or an object per language.
+const pickText = (x) => (typeof x === 'string' ? x : (x?.[lang] ?? x?.en ?? Object.values(x || {})[0] ?? ''));
+
+async function loadPresets() {
+  try {
+    const res = await api('/api/presets');
+    state.presets = res.groups || [];
+    if (res.error) toast(t('presetsFileErr', res.file) + res.error);
+  } catch (e) { toast(e.message); }
+  renderPresets();
+}
+
+function renderPresets() {
+  $('#presetTags').innerHTML = `<option value="">${esc(t('presetPick'))}</option>`
+    + state.presets.map((g) => `<optgroup label="${esc(pickText(g.group))}">`
+      + g.presets.map((p) => `<option value="${esc(p.id)}">${esc(pickText(p.name))}</option>`).join('') + '</optgroup>').join('');
+}
+
 async function loadTags() {
   try { state.tags = await api('/api/tags'); } catch (e) { toast(t('tagsLoadErr') + e.message); }
   compileMatchers();
@@ -1987,9 +2079,10 @@ function tagRowHTML(tag) {
   const opt = (field, label, title) =>
     `<label class="opt" title="${esc(title)}"><input type="checkbox" data-f="${field}"${tag[field] ? ' checked' : ''}>${esc(label)}</label>`;
   return `<div class="tag-row${tag.enabled ? '' : ' off'}" data-id="${esc(tag.id)}">
+    <span class="tag-code" title="${esc(t('tagCodeTitle'))}">${esc(tag.code || '··')}</span>
     <input type="color" value="${esc(tag.color)}" data-f="color" aria-label="${esc(t('colorAria'))}">
     <input type="text" value="${esc(tag.pattern)}" data-f="pattern" placeholder="${esc(t('keyword'))}" spellcheck="false" aria-label="${esc(t('keyword'))}">
-    <span class="preview"><mark class="tag" style="${tagStyle(tag.color)}">${esc(tag.pattern || t('preview'))}</mark></span>
+    <span class="preview" title="${esc(tag.pattern)}"><mark class="tag" style="${tagStyle(tag.color)}">${esc(tag.label || tag.pattern || t('preview'))}</mark></span>
     <div class="opts">
       ${opt('wholeWord', t('optWhole'), t('optWholeTitle'))}
       ${opt('caseSensitive', 'Aa', t('optCaseTitle'))}
@@ -2032,7 +2125,7 @@ $('#tagList').addEventListener('input', (ev) => {
   tag[field] = ev.target.type === 'checkbox' ? ev.target.checked : ev.target.value;
   rowEl.classList.toggle('off', !tag.enabled);
   const mark = rowEl.querySelector('.preview mark');
-  mark.textContent = tag.pattern || t('preview');
+  mark.textContent = tag.label || tag.pattern || t('preview');
   mark.setAttribute('style', tagStyle(tag.color));
   scheduleSave(tag, rowEl);
   applyTags();
@@ -2065,6 +2158,25 @@ $('#addTag').addEventListener('click', async () => {
   } catch (e) { toast(e.message); }
 });
 
+// Adds a preset group, skipping tags whose pattern is already in the list.
+$('#presetTags').addEventListener('change', async (ev) => {
+  const preset = state.presets.flatMap((g) => g.presets).find((p) => p.id === ev.target.value);
+  ev.target.value = '';
+  if (!preset) return;
+  let added = 0;
+  try {
+    for (const p of preset.tags) {
+      if (state.tags.some((x) => x.pattern === p.pattern)) continue;
+      const tag = { ...p, label: pickText(p.label), regex: p.regex ?? true, enabled: true };
+      state.tags.push(await api('/api/tags', { method: 'POST', body: tag }));
+      added++;
+    }
+  } catch (e) { toast(e.message); }
+  renderTagList();
+  applyTags();
+  toast(t('presetAdded', added));
+});
+
 $('#resetTags').addEventListener('click', async () => {
   if (!confirm(t('confirmReset'))) return;
   try {
@@ -2077,6 +2189,7 @@ $('#resetTags').addEventListener('click', async () => {
 $('#settingsBtn').addEventListener('click', () => {
   renderTimeSettings();
   renderTagList();
+  loadPresets();
   renderInterface();
   loadPurgeStatus();
   loadSyslog();
@@ -2098,6 +2211,7 @@ $('#settingsDlg').addEventListener('click', (ev) => { if (ev.target === ev.curre
 }
 applyLogFont(store.get('logFont', 'system'));
 applyLogSize(store.get('logSize', 'medium'));
+applyLogDensity(store.get('logDensity', 'normal'));
 applyLang();
 $('#range').value = store.get('range', '1h');
 if (!$('#range').value) $('#range').value = '1h';

web/fonts/OFL-Inconsolata.txt

@@ -0,0 +1,93 @@
+Copyright 2006 The Inconsolata Project Authors (https://github.com/cyrealtype/Inconsolata)
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.

web/fonts/OFL-Iosevka.txt

@@ -0,0 +1,110 @@
+Copyright (c) 2015-2023, Renzhi Li (aka. Belleve Invis, belleve@typeof.net)
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+--------------------------
+
+
+SIL Open Font License v1.1
+====================================================
+
+
+Preamble
+----------
+
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded, 
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+
+Definitions
+-------------
+
+`"Font Software"` refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+`"Reserved Font Name"` refers to any names specified as such after the
+copyright statement(s).
+
+`"Original Version"` refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+`"Modified Version"` refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+`"Author"` refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+
+Permission & Conditions
+------------------------
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1. Neither the Font Software nor any of its individual components,
+   in Original or Modified Versions, may be sold by itself.
+
+2. Original or Modified Versions of the Font Software may be bundled,
+   redistributed and/or sold with any software, provided that each copy
+   contains the above copyright notice and this license. These can be
+   included either as stand-alone text files, human-readable headers or
+   in the appropriate machine-readable metadata fields within text or
+   binary files as long as those fields can be easily viewed by the user.
+
+3. No Modified Version of the Font Software may use the Reserved Font
+   Name(s) unless explicit written permission is granted by the corresponding
+   Copyright Holder. This restriction only applies to the primary font name as
+   presented to the users.
+
+4. The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+   Software shall not be used to promote, endorse or advertise any
+   Modified Version, except to acknowledge the contribution(s) of the
+   Copyright Holder(s) and the Author(s) or with their explicit written
+   permission.
+
+5. The Font Software, modified or unmodified, in part or in whole,
+   must be distributed entirely under this license, and must not be
+   distributed under any other license. The requirement for fonts to
+   remain under this license does not apply to any document created
+   using the Font Software.
+
+
+
+Termination
+-----------
+
+This license becomes null and void if any of the above conditions are
+not met.
+
+
+    DISCLAIMER
+    
+    THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+    OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+    COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+    INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+    DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+    OTHER DEALINGS IN THE FONT SOFTWARE.

web/fonts/UFL-Ubuntu-Mono.txt

@@ -0,0 +1,96 @@
+-------------------------------
+UBUNTU FONT LICENCE Version 1.0
+-------------------------------
+
+PREAMBLE
+This licence allows the licensed fonts to be used, studied, modified and
+redistributed freely. The fonts, including any derivative works, can be
+bundled, embedded, and redistributed provided the terms of this licence
+are met. The fonts and derivatives, however, cannot be released under
+any other licence. The requirement for fonts to remain under this
+licence does not require any document created using the fonts or their
+derivatives to be published under this licence, as long as the primary
+purpose of the document is not to be a vehicle for the distribution of
+the fonts.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this licence and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Original Version" refers to the collection of Font Software components
+as received under this licence.
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to
+a new environment.
+
+"Copyright Holder(s)" refers to all individuals and companies who have a
+copyright ownership of the Font Software.
+
+"Substantially Changed" refers to Modified Versions which can be easily
+identified as dissimilar to the Font Software by users of the Font
+Software comparing the Original Version with the Modified Version.
+
+To "Propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy. Propagation includes copying,
+distribution (with or without modification and with or without charging
+a redistribution fee), making available to the public, and in some
+countries other activities as well.
+
+PERMISSION & CONDITIONS
+This licence does not grant any rights under trademark law and all such
+rights are reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a
+copy of the Font Software, to propagate the Font Software, subject to
+the below conditions:
+
+1) Each copy of the Font Software must contain the above copyright
+notice and this licence. These can be included either as stand-alone
+text files, human-readable headers or in the appropriate machine-
+readable metadata fields within text or binary files as long as those
+fields can be easily viewed by the user.
+
+2) The font name complies with the following:
+(a) The Original Version must retain its name, unmodified.
+(b) Modified Versions which are Substantially Changed must be renamed to
+avoid use of the name of the Original Version or similar names entirely.
+(c) Modified Versions which are not Substantially Changed must be
+renamed to both (i) retain the name of the Original Version and (ii) add
+additional naming elements to distinguish the Modified Version from the
+Original Version. The name of such Modified Versions must be the name of
+the Original Version, with "derivative X" where X represents the name of
+the new work, appended to that name.
+
+3) The name(s) of the Copyright Holder(s) and any contributor to the
+Font Software shall not be used to promote, endorse or advertise any
+Modified Version, except (i) as required by this licence, (ii) to
+acknowledge the contribution(s) of the Copyright Holder(s) or (iii) with
+their explicit written permission.
+
+4) The Font Software, modified or unmodified, in part or in whole, must
+be distributed entirely under this licence, and must not be distributed
+under any other licence. The requirement for fonts to remain under this
+licence does not affect any document created using the Font Software,
+except any version of the Font Software extracted from a document
+created using the Font Software may only be distributed under this
+licence.
+
+TERMINATION
+This licence becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
+COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM OTHER
+DEALINGS IN THE FONT SOFTWARE.

web/index.html

@@ -3,7 +3,7 @@
 <head>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <title>Logstream</title>
+  <title>LogStream</title>
   <link rel="icon" href="data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'%3E%3Crect width='32' height='32' rx='8' fill='%236366f1'/%3E%3Cpath d='M8 10h16M8 16h11M8 22h14' stroke='white' stroke-width='3' stroke-linecap='round'/%3E%3C/svg%3E">
   <link rel="stylesheet" href="style.css">
   <script>
@@ -20,7 +20,7 @@
   <header class="topbar">
     <div class="brand">
       <svg viewBox="0 0 32 32" aria-hidden="true"><rect width="32" height="32" rx="8"/><path d="M8 10h16M8 16h11M8 22h14"/></svg>
-      <span>Logstream</span>
+      <span>LogStream</span>
     </div>
 
     <div class="search">
@@ -107,6 +107,7 @@
       <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="msg"><span class="lbl" data-i18n="colMsg">Message</span></span>
     </div>
     <main id="list" class="list"></main>
@@ -188,7 +189,12 @@
               <p class="muted small" data-i18n="tagsHelp"></p>
               <div id="tagList" class="tag-list"></div>
               <footer>
-                <button id="addTag" class="btn primary" type="button" data-i18n="addTag">+ Add tag</button>
+                <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>
+                  </select>
+                </span>
                 <button id="resetTags" class="btn ghost" type="button" data-i18n="resetTags">Restore default tags</button>
               </footer>
             </section>
@@ -271,6 +277,11 @@
                   <button type="button" role="radio" data-size="medium" data-i18n="sizeMedium">Medium</button>
                   <button type="button" role="radio" data-size="large" data-i18n="sizeLarge">Large</button>
                 </div>
+                <span class="lbl" data-i18n="density">Density</span>
+                <div id="densitySwitch" class="seg" role="radiogroup" data-i18n-aria="density">
+                  <button type="button" role="radio" data-density="normal" data-i18n="densityNormal">Normal</button>
+                  <button type="button" role="radio" data-density="compact" data-i18n="densityCompact">Compact</button>
+                </div>
                 <label for="fontSelect" data-i18n="fontLabel">Font</label>
                 <select id="fontSelect" class="field"></select>
               </div>

web/login.html

@@ -3,7 +3,7 @@
 <head>
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
-  <title>Logstream</title>
+  <title>LogStream</title>
   <link rel="icon" href="data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 32 32'%3E%3Crect width='32' height='32' rx='8' fill='%236366f1'/%3E%3Cpath d='M8 10h16M8 16h11M8 22h14' stroke='white' stroke-width='3' stroke-linecap='round'/%3E%3C/svg%3E">
   <link rel="stylesheet" href="style.css">
   <script>
@@ -32,7 +32,7 @@
     <img id="logo" class="login-logo" src="auth/logo" alt="" hidden>
     <div class="brand">
       <svg viewBox="0 0 32 32" aria-hidden="true"><rect width="32" height="32" rx="8"/><path d="M8 10h16M8 16h11M8 22h14"/></svg>
-      <span>Logstream</span>
+      <span>LogStream</span>
     </div>
     <p class="muted" data-i18n="intro">Sign in to view the logs.</p>
 

web/style.css

@@ -1,3 +1,13 @@
+/* Narrow monospace fonts served by LogStream itself, so they also work offline (licences in
+   web/fonts). Latin subset only; other scripts fall back to --mono. Inconsolata Condensed is
+   Inconsolata's variable font pinned at width 75 (0.4em per character, others 0.5em). */
+@font-face { font-family: "Iosevka"; src: url("fonts/iosevka-400.woff2") format("woff2"); font-weight: 400 500; font-display: swap; }
+@font-face { font-family: "Iosevka"; src: url("fonts/iosevka-700.woff2") format("woff2"); font-weight: 600 800; font-display: swap; }
+@font-face { font-family: "Ubuntu Mono"; src: url("fonts/ubuntu-mono-400.woff2") format("woff2"); font-weight: 400 500; font-display: swap; }
+@font-face { font-family: "Ubuntu Mono"; src: url("fonts/ubuntu-mono-700.woff2") format("woff2"); font-weight: 600 800; font-display: swap; }
+@font-face { font-family: "Inconsolata Condensed"; src: url("fonts/inconsolata-condensed-400.woff2") format("woff2"); font-weight: 400 500; font-display: swap; }
+@font-face { font-family: "Inconsolata Condensed"; src: url("fonts/inconsolata-condensed-700.woff2") format("woff2"); font-weight: 600 800; font-display: swap; }
+
 /* ---------- Theme: everything goes through these variables ---------- */
 :root {
   --bg: #f6f7f9;
@@ -38,6 +48,8 @@
   --tag-warning-text: #111827;
 
   --log-size: 12.5px;   /* Settings > Interface > Font size */
+  --codes-w: 4.9rem;    /* tag codes column: room for 3 badges */
+  --code-bg: #858c97;   /* tag code badges */
   /* --log-font is set by Settings > Interface > Font (defaults to --mono) */
   --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Cascadia Code", Menlo, Consolas, monospace;
   --sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
@@ -296,13 +308,13 @@ 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, message. Widths come from
+/* Columns: 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)
-    var(--col-host, minmax(5rem, 9rem)) var(--col-app, minmax(4rem, 8rem)) minmax(0, 1fr);
+    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);
   overflow: clip; /* rounded corners without breaking the sticky header (hidden would) */
@@ -331,7 +343,7 @@ 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) 1fr;
+  grid-template-columns: 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;
   border-left: 3px solid transparent;
@@ -341,6 +353,10 @@ body.col-resizing, body.col-resizing * { cursor: col-resize !important; user-sel
   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; }
 .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; }
@@ -372,6 +388,17 @@ 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; }
+/* 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;
+  /* 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;
+  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); }
 .row .host[data-act]:hover, .row .app[data-act]:hover { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
 
 mark.tag {
@@ -475,6 +502,7 @@ dialog.settings .dlg > header { padding: 14px 16px 14px 22px; border-bottom: 1px
 .preview-list .row .host { grid-area: host; }
 .preview-list .row .app { grid-area: app; display: block; }
 .preview-list .row .msg { grid-area: msg; }
+.preview-list .row .codes { display: none; }
 
 dialog {
   width: min(720px, calc(100vw - 32px)); max-height: calc(100vh - 64px);
@@ -578,6 +606,8 @@ 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; }
 
 .seg { display: inline-flex; padding: 3px; gap: 3px; background: var(--panel-2); border: 1px solid var(--border); border-radius: 10px; }
 .seg button {
@@ -590,11 +620,12 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
 .tag-list { display: flex; flex-direction: column; gap: 8px; margin-top: 12px; }
 .tag-row {
   display: grid; align-items: center; gap: 8px 10px;
-  grid-template-columns: 38px minmax(8rem, 1fr) 7.5rem auto 36px;
+  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);
 }
 .tag-row.off { opacity: .55; }
+.tag-row .tag-code { font-size: 12px; padding: 3px 6px; cursor: default; }
 .tag-row input[type="color"] {
   width: 38px; height: 32px; padding: 0; border: 1px solid var(--border); border-radius: 8px;
   background: none; cursor: pointer;
@@ -637,8 +668,8 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
   .table .list { display: block; margin: 0; }
   .list-head { display: none; }
   .row, .table .row {
-    grid-template-columns: auto auto 1fr;
-    grid-template-areas: "rcv sev host" "msg msg msg";
+    grid-template-columns: auto auto 1fr auto;
+    grid-template-areas: "rcv sev host codes" "msg msg msg msg";
     gap: 3px 8px; padding: 8px 12px 8px 10px;
   }
   .row time.rcv { grid-area: rcv; }
@@ -646,6 +677,7 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
   .row .sev { grid-area: sev; }
   .row .host { grid-area: host; justify-self: end; max-width: 100%; }
   .row .app { display: none; }
+  .row .codes { grid-area: codes; }
   .row .msg { grid-area: msg; }
   .details { grid-column: 1 / -1; }
   .details dl { grid-template-columns: 1fr; }
@@ -663,14 +695,15 @@ input.switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2
   }
   .set-nav button span { max-width: 100%; overflow: hidden; text-overflow: ellipsis; }
   .set-panels { padding: 0 16px 18px; }
-  #sizeSwitch { display: flex; }
-  #sizeSwitch button { flex: 1; padding: 0 4px; white-space: nowrap; font-size: 12px; }
+  #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: 38px 1fr 36px; }
+  .tag-row { grid-template-columns: auto 38px 1fr 36px; }
   .tag-row .preview { display: none; }
   .tag-row .opts { grid-column: 1 / -1; grid-row: 2; flex-wrap: wrap; }
-  .tag-row [data-del] { grid-column: 3; grid-row: 1; }
+  .tag-row [data-del] { grid-column: 4; grid-row: 1; }
 }
 
 /* ---------- Login page (AUTH_MODE=local) ---------- */