# Logging framework

Decided 2026-11-01, and the store chosen on 2026-11-03: **VictoriaLogs**, on the `diag.BASE` host with its UI
at `/logs` (Phase 14 in `CommunityDiscordMedia.md`). Everything upstream of the store was fixed first, so
adopting it is a collector config rather than a code change.

## Where the lines come from (the only two taps a collector needs)

| Tap | Holds | Read with |
|---|---|---|
| **journald** | our systemd units: `dumpd`, `normalize-sweep`, `trash-purge`, `deploy-pending`, `vgdeband` (transient), `deploy.sh` output | `journalctl -u <unit>`; collectors: Alloy `loki.source.journal`, Vector `journald`, VictoriaLogs journald ingestion, Netdata's journal plugin |
| **Docker json-file logs** | every container (`docker-compose.yml`), rotated 5 × 50 MB each | `docker logs <name>`; collectors read `/var/lib/docker/containers/*/*-json.log` and get the container **labels** below for free |

Every collector on the shortlist reads both. Metrics are the same story: see the taps table below — all four endpoints are on now, on loopback.

## Metrics taps (all Prometheus text format, loopback only — scrape them with Alloy, vmagent or Netdata)

| endpoint | what | from |
|---|---|---|
| `http://127.0.0.1:9100/metrics` | host: CPU, RAM, disk space + I/O, network, load, md RAID | node_exporter (host network, pid host) |
| `http://127.0.0.1:9101/metrics` | per container: CPU, memory, network, block I/O — labelled with `vanguard.service` / `vanguard.category` | cAdvisor |
| `http://127.0.0.1:9998/metrics` | MediaMTX: per path bytes/s, readers, publishers, WebRTC/HLS/RTMP sessions, dropped packets | MediaMTX `metrics: yes` |
| `http://127.0.0.1:2019/metrics` | Caddy: requests by host/status, durations, TLS | Caddy admin API (`servers { metrics }`) |

None of these are reachable from outside (loopback binds; nothing in the firewall). Nothing evaluates them yet:
metric alerting needs VictoriaMetrics scraping them plus vmalert, and log alerting needs vmalert against
VictoriaLogs' stats endpoints with Alertmanager for delivery (Phase 14). Thresholds to start with: disk on
`/srv` > 85 %, load > cores for 15 min, a container restarting, MediaMTX dropped packets rising on a live path.

## Container labels (set in `docker-compose.yml`, `x-logging` anchor + `labels:`)

`vanguard.service` = the service name, `vanguard.category` = one of the categories below. A collector turns these
into stream labels without parsing a single line.

## Categories = the questions people ask

| category | services / components | correlation key |
|---|---|---|
| `stream` | mediamtx (path ready/closed, recorder, WebRTC sessions, the on-ready hook's `event=mirror`), dumpd `publish_allow` / `publish_deny`, sweep `event=published` | `stream` = `user/Title` |
| `auth` | caddy access logs (status, `X-Authentik-Username`), authentik-server/worker events, gitea OIDC | `user` |
| `media` | sweep verdicts / timecode / deband / failed, vgdeband, jellyfin, copyparty | `file` |
| `intake` | syncthing (`folder.id`), dumpd `clips_setup`, `quota_*` | `folder` = `clips-<user>` |
| `infra` | mariadb, caddy TLS/ACME, container restarts, disk | host only |
| `deploy` | deploy.sh, dumpd `deploy_*`, `bot_deploy_*` and `bot_env_*` (the bot's CI posting a release bundle and its settings), act_runner | `rev` |
| `code`, `bot` | gitea, discord-bot | — |

## Labels vs fields

- **Labels** (low cardinality, what you filter by): `service`, `category`, `level`, `unit`. A dozen values each.
- **Fields** (parsed at query time, what you search in): `stream`, `user`, `file`, `folder`, `session`, `status`, `ip`, `event`.
  Thousands of values — fine as fields, ruinous as labels (Loki). VictoriaLogs indexes every word anyway.

## Our own line format: logfmt, one event per line

    ts=2026-11-01T19:52:14-06:00 level=info component=sweep event=published stream="techy2493/Vanguard_Training" file="/srv/media/streams/…" verdict=encode

- `ts` ISO-8601 with offset · `level` info|warn|error · `component` dumpd|sweep|vgdeband|deploy|on-ready · `event` a verb/noun in snake_case · then `key=value`, values with spaces or quotes double-quoted.
- Same key means the same thing everywhere: `stream` (user/Title), `user`, `file`, `folder`, `rev`, `ip`, `reason`.
- Implemented by: `log()` in `bin/dumpd.py`, `vglog` in `bin/normalize-sweep.sh` and `bin/vgdeband.sh`, `log()` in `deploy.sh` (`msg=` only), `bin/mtx-on-ready.sh` (MediaMTX prefixes its own path/time).

Events today: dumpd `publish_allow publish_deny dump clips_setup quota_paused quota_resumed quota_* deploy_* bot_deploy_start bot_deploy_exit bot_deploy_bad_signature bot_deploy_refused bot_env_applied bot_env_failed`;
sweep `verdict timecode deband fill_gaps published done failed skip`; vgdeband `deband done failed skip`; hook `mirror`.
A future alert script watches `level=error`, `event=failed`, `event=publish_deny` bursts, `event=quota_paused`, plus disk.

## Third-party formats a collector must parse

| source | format | stage |
|---|---|---|
| caddy | JSON (`logger`, `level`, `msg`; access logs: `request.*`, `status`, `request.headers.X-Authentik-Username`) | json |
| authentik | JSON (`event`, `user`, `action`) | json |
| syncthing | key=value after a `date time:` prefix (`folder.id=… log.pkg=model`) | logfmt |
| mediamtx | `YYYY/MM/DD HH:MM:SS LVL [component] [session|path x] message` | one regex → component, id, msg |
| jellyfin | `[HH:MM:SS.mmm] [LVL] [thread] Logger.Class: message` + stack-trace continuation lines | **multiline** (join lines not starting with `[`) then regex |
| gitea, mariadb, copyparty | plain text | level regex only |

## Caddy access logs

On for every site block (`CADDY_LOG` in `configure.py`): JSON to stderr; `Cookie`, `Authorization` and
`X-Stream-Auth` request headers are deleted before logging, the `X-Authentik-*` identity headers are kept — that is the
"who downloaded what" audit trail for the files host.

## Retention

One global retention period in VictoriaLogs (`-retentionPeriod`); start at 30 days and watch the disk. Keeping
`auth` and `deploy` longer than the rest would need separate tenants, which is not worth it unless an audit does.

## As built (Phase 13)

| container | port | job |
|---|---|---|
| `victorialogs` | 9428 | store, 30 d, `-http.pathPrefix=/logs` so Caddy passes the prefix through unchanged |
| `vector` | — | `docker_logs` + `journald` → VictoriaLogs (elasticsearch bulk). **Holds the Docker socket** |
| `victoriametrics` | 8428 | 90 d, scrapes the taps above (`observability/scrape.yml`) |
| `vmalert-metrics` | 8880 | `observability/alerts-metrics.yml` against VictoriaMetrics |
| `vmalert-logs` | 8881 | `observability/alerts-logs.yml` (LogsQL) against VictoriaLogs' stats endpoints |
| `alertmanager` | 9093 | groups, inhibits, posts to Discord (`webhook_url_file`, never in the config) |

Published only through `diag.BASE`, gated on `DIAG_REQUIRE_GROUP` (`media-admins`): `/logs`, `/metrics-db`,
`/alerts`, `/rules-metrics`, `/rules-logs`, and an index at `/`.

**The deadman** (`bin/vanguard-deadman.sh`, host timer, 5 min) is deliberately outside all of it: curl only, it
checks each component answers, that the always-firing `Watchdog` alert is still arriving through
vmalert → Alertmanager → dumpd `/heartbeat`, and the disks. It speaks on change, announces recovery once, and
with no webhook configured still logs and exits non-zero so `systemctl is-failed vanguard-deadman.service` is
a signal. Nothing inside the stack can report its own death; this can.

`ALERT_WEBHOOK_URL` in `.env` → `/etc/vanguard/alert-webhook` (0640 root:65534). Empty means log-only, which
is a working configuration, not an error.

## Wiring sketches (the options that were weighed)

- **Grafana + Loki**: `alloy` container with `loki.source.journal` + `loki.source.docker` (labels from the container
  labels above) → `loki` on loopback → `grafana` behind Authentik OIDC (third provider, like Jellyfin/Gitea).
  Metrics: Alloy scrapes the four taps above → Prometheus or VictoriaMetrics, same Grafana.
- **VictoriaLogs** (chosen): single container on `127.0.0.1:9428`, run with `-http.pathPrefix=/logs`; Vector
  ships journald and the Docker logs. Its built-in UI sits behind the Caddy forward-auth gate on `diag.BASE`
  (`media-admins`). VictoriaMetrics beside it would consume the four metric taps.
- **Netdata**: single container, host + container metrics and alerts (Discord) out of the box, journald viewer;
  behind the Caddy gate. Weakest at log search.
- **ELK**: rejected — JVM heap and index disk on a box doing x264; our data is structured records (→ MariaDB) and a
  single host's logs.