Observability¶

Revel ships a full LGTM-style observability stack, but it is off by default on Slim instances because it costs several gigabytes of RAM. Turn it on when you want dashboards, log search, and distributed traces.

Enabling the stack¶

Add the observability profile to your COMPOSE_PROFILES in .env:

COMPOSE_PROFILES=observability

(Combine it with other profiles as needed, e.g. observability,antivirus.) Then re-run docker compose up -d to start the additional services.

The application-side toggle is the FEATURE_OBSERVABILITY environment variable, which enables the metrics/traces/logs exporters and the async log queue inside the Django and Celery processes:

FEATURE_OBSERVABILITY=True

What each tool does¶

• Prometheus — scrapes and stores time-series metrics from the services.
• Loki — aggregates and indexes logs so you can search across all containers.
• Tempo — stores distributed traces for following a request across services. Credential-bearing query parameters (token, sig, ot, et, code, state) and path secrets (invitation-link tokens, the integrations webhook secret) are replaced with REDACTED in span attributes before export.
• Pyroscope — continuous profiling, for finding CPU/memory hot spots.
• Alloy — the collection agent that ships metrics, logs, and traces into the above.
• Grafana — the single UI that ties Prometheus, Loki, Tempo, and Pyroscope together with dashboards and explore views.

Grafana login¶

Grafana's admin credentials are set via environment variables in .env (the wizard generates a random password for you):

• GRAFANA_ADMIN_USER — the admin username (defaults to admin).
• GRAFANA_ADMIN_PASSWORD — the admin password.

Compose passes these to Grafana as GF_SECURITY_ADMIN_USER / GF_SECURITY_ADMIN_PASSWORD. Set them before first start; once Grafana initializes its database, changing the password is done in the Grafana UI rather than via the env var. Grafana is reachable at https://grafana.<your-domain> once DNS and certificates are in place.

Resource cost¶