thermograph/observability/CLAUDE.md

observability/ — agent instructions

The logging stack for the fleet: Loki + Grafana on beta, with a Grafana Alloy agent on every node (prod, beta, dev) shipping container and app logs over the WireGuard mesh. Grafana is fronted by beta's Caddy at dashboard.thermograph.org (Google SSO, pre-provisioned users only) — use that hostname everywhere, never grafana.thermograph.org.

This is operational config, not application code: there is no build and no deploy automation. It ships by hand — docker compose up -d on beta for Loki+Grafana, and alloy/docker-compose.agent.yml on each node. Read the root CLAUDE.md first; the branch model there applies here too.

Layout

• docker-compose.yml — the Loki + Grafana stack (beta).
• loki/config.yml — mesh-only, filesystem storage.
• grafana/provisioning/ — datasource + dashboard provider, auto-loaded at startup. grafana/dashboards/*.json — the dashboards.
• grafana/provisioning/alerting/ — alert rules, the Discord contact point, and the notification policy.
• alloy/config.alloy + alloy/docker-compose.agent.yml — the per-node shipper. Node name comes from ALLOY_NODE, set per host.
• caddy-grafana.conf — the beta Caddy vhost, kept here for reference.
• .env.example — copy to .env on beta. .env is gitignored; never commit OAuth secrets or the admin password.

Rules

• The repo is the only durable path. Dashboards and alerting are provisioned from this directory at startup; edits made through Grafana's UI or API are overwritten on the next provision. Changes go through a PR.
• Every artifact that ships to a node is CI-validated (.forgejo/workflows/observability-validate.yml, at the repo root): both compose files parse, all dashboard JSON is valid, the Loki and provisioning YAML parse, and the Alloy config is checked with the pinned alloy binary (v1.9.1, matching what the fleet runs).
• Alerting gets a stricter third step. Every rule's condition must name a refId that exists, every policy must route to a receiver that exists, and a literal Discord webhook URL in the repo is a hard failure. A rule pointing at a missing refId is valid YAML, provisions cleanly, and then never fires — that silent no-op is what this check exists to prevent.
• Alerts go to Discord #ops-alerts, never email. Beta's Grafana relays SMTP through prod's Postfix, so email dies exactly when prod does.
• Every rule is LogQL — there is no Prometheus anywhere in the fleet. Thresholds were derived from real Loki data and the working is in the comments beside each rule; re-derive before changing a number rather than guessing.
• Secrets (OAuth client id/secret, admin password) live only in the host .env.

Commits & PRs

Concise and technical. Never mention AI, assistants or automated authorship.