monitor-setuplisted

# Step 7: Monitor (เฝ้าระวัง) **Habit**: H7 — Sharpen the Saw | **Anti-pattern**: Deploying and forgetting — "it works on my machine" ## Process 1. **Check existing monitoring**: Search for health endpoints, Prometheus configs, Grafana dashboards, alerting rules — don't duplicate what exists. 2. **Verify minimum observability**: - [ ] Health endpoint exists (`/health` or `/healthz`) - [ ] Error rate is trackable (metrics or logs) - [ ] Alerting is configured (email, Slack, PagerDuty) - [ ] Logs are accessible (not just stdout) 3. **If monitoring gaps found**, recommend additions: - Health endpoint: simple `/health` returning `{"status":"healthy","version":"x.y.z"}` - Error tracking: Sentry, Prometheus alert rules, or log aggregation - Uptime monitoring: health check ping every 30-60s - Disk/memory alerts: warn at 85%, critical at 95% 4. **Infrastructure health** (prevent cascade failures): - [ ] Disk space monitoring with alerts before exhaustion - [ ] Dependent services checked (DB, cache, queue) — if one dies, what cascades? - [ ] Container/process auto-restart configured (Docker restart policy, systemd) - [ ] Recovery runbook exists for each critical dependency 5. **Post-deploy monitoring habit**: ``` After every deploy: 1. Check health endpoint returns correct version 2. Verify key features work (smoke test) 3. Watch error rate for 5 minutes 4. Check no new alerts fired 5. Record any incidents for future lea