Media-Server-Setup/LOGGING.md

# Logging framework — store-agnostic

Decided 2026-11-01. The log *store* (Grafana + Loki, VictoriaLogs, Netdata, …) is not chosen yet. Everything
upstream of it is fixed now, so the choice later is a collector config, not 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). Alert 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_*`, 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_*`;
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 (when a store exists)

14 days for everything; 90 for `auth` and `deploy`. Both Loki and VictoriaLogs do per-stream retention.

## Wiring sketches (not deployed; pick one later)

- **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**: single container, journald + docker via its agent or Vector; built-in UI behind the Caddy
  forward-auth gate (`media-admins`). VictoriaMetrics beside it for metrics.
- **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.