# observability stack

phase 0 close-out — grafana + loki + prometheus + promtail on a single dokploy compose project. lives on the same docker network as `apps/api`, `apps/runtime`, `apps/realtime` so prometheus scrapes container names directly. grafana is exposed via traefik behind cloudflare access; everything else is internal-only.

## what's here

```
infra/observability/
├── compose.yml                                   # the stack
├── loki/config.yaml
├── promtail/config.yaml
├── prometheus/
│   ├── prometheus.yml
│   └── rules/services.yml
├── grafana/
│   ├── grafana.ini
│   ├── provisioning/datasources/datasources.yaml
│   ├── provisioning/dashboards/dashboards.yaml
│   └── dashboards/
│       ├── api-requests.json
│       ├── runtime-invocations.json
│       ├── realtime-subs.json
│       └── postgres-health.json
└── README.md  (this file)
```

## what's emitted today vs. needed

prometheus scrape targets in `prometheus.yml`:

| service     | /metrics    | metrics emitted today                                                                                                                              | needed for full dashboards                                                                                            |
| ----------- | ----------- | -------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| `api`       | ✅ shipped  | `http_requests_total{method,status,route}`, `http_request_duration_ms_bucket{method,route,le}`                                                     | already covered — see `apps/api/src/lib/metrics.ts` + `apps/api/src/middleware/metrics.ts`                            |
| `runtime`   | ✅ shipped  | pool gauges, cold-start histogram, isolate kill counter                                                                                            | already covered — see `apps/runtime/src/metrics.ts`                                                                   |
| `realtime`  | ✅ shipped  | `briven_realtime_subscriptions_active`, `briven_realtime_channels_active`, `briven_realtime_notifies_total`, `briven_realtime_reinvoke_total{outcome}` | already covered — see `apps/realtime/src/metrics.ts`                                                                  |
| `postgres`  | ⚙️ template ready | none until deployed                                                                                                                                | merge `./postgres-exporter.compose.yml` into the data-plane compose project + create a `briven_metrics` role (`GRANT pg_monitor`) + set `POSTGRES_EXPORTER_DATA_SOURCE_NAME`. exporter binds to `postgres-exporter:9187`, already in `prometheus.yml`. |

dashboards reference these metric names and will show "no data" until the corresponding service starts emitting them. that's deliberate — the dashboards land first so adding a metric is a one-line change.

logs are scraped by promtail using **file-based discovery** against `/var/lib/docker/containers/*/*-json.log` (read-only bind-mount). per `DOCKER.md` we never touch `/var/run/docker.sock` or `docker_sd_configs` — the daemon is shared with other projects on the host and every API call goes through internal locks. promtail reads the json log files directly, unwraps the docker envelope, then parses the `service` field from each briven service's own JSON log line (emitted by `@briven/shared/observability`). non-briven containers ship through with `service` absent and Loki queries scope by `{service=~"api|runtime|realtime|web|docs"}`.

## deploy on dokploy

```bash
# on the kvm running the briven docker network:
cd infra/observability
docker network create briven 2>/dev/null || true   # idempotent
docker compose up -d
```

verify:

```bash
curl -fsS http://localhost:9090/-/ready          # prometheus ready
curl -fsS http://localhost:3100/ready            # loki ready
docker compose ps                                 # all four containers up
```

then point cloudflare access at `grafana.briven.tech` (the traefik labels in `compose.yml` cover the rest).

## scale-out path

phase 0 ships single-binary loki + local-disk storage. when log ingest exceeds ~50gb/day or query latency degrades:

1. swap loki's `common.storage.filesystem` for `s3` (minio or cloudflare r2)
2. enable loki microservices mode (separate distributor / ingester / querier containers)
3. move prometheus to a clustered mode (vmagent → vmsingle, or thanos)

the dashboards and scrape configs don't change.

## alerting

`prometheus/rules/services.yml` defines `ServiceDown`, `HighErrorRate`, `PostgresConnectionsHigh`. they route through alertmanager → `benjojo/alertmanager-discord` bridge → discord:

- `severity=critical|warning` → `#briven-alerts` (page-worthy)
- everything else (info) → `#briven-deploys`

operator env on the dokploy project:

```
DISCORD_WEBHOOK_ALERTS=https://discord.com/api/webhooks/…
DISCORD_WEBHOOK_DEPLOYS=https://discord.com/api/webhooks/…
```

create the channels in your discord server, generate webhook URLs, paste into the dokploy env. each bridge instance holds one URL; rotation = update env + restart that one service. existing alert state lives in the `alertmanager_data` volume — keep it across redeploys so silences carry through.

smoke test (drop a rule's `for:` to 0s temporarily, observe a message land, revert):

```
docker compose exec prometheus promtool query instant 'up'
docker compose restart prometheus
# … wait for the rule to fire …
# then revert the rule edit and `docker compose restart prometheus` again.
```

## the four dashboards

uids stay stable across redeploys — bookmark them.

- `briven-api-requests` — request rate, p99 latency, 5xx error rate, recent error logs
- `briven-runtime-invocations` — invocations/sec by project, cold-start p50/p99, active isolates, kills by reason
- `briven-realtime-subs` — active subscriptions, LISTEN channels, NOTIFY rate, listener reconnect events
- `briven-postgres-health` — connections, transactions/sec, deadlocks, longest query, db size by schema
