health

# Health Check $ARGUMENTS Check the health of all project services. ## Project context - Services: !`docker compose ps 2>/dev/null || echo "no-docker"` ## Auto-Detection Detect services from `docker-compose.yml`, `.env`, or project configuration. ### Quick Check ```bash # If using Docker Compose docker compose ps # Process check (bare metal) ps aux | grep -E "(node|python|java|php)" | grep -v grep ``` ## Common Service Checks | Service | Health Check | |---------|-------------| | HTTP API | `curl -f http://localhost:{port}/health` | | PostgreSQL | `pg_isready -h localhost -p 5432` | | MySQL | `mysqladmin ping -h localhost` | | Redis | `redis-cli ping` | | MongoDB | `mongosh --eval "db.runCommand({ping:1})"` | | Elasticsearch | `curl -f http://localhost:9200/_cluster/health` | | RabbitMQ | `curl -f http://localhost:15672/api/healthchecks/node` | ## Diagnostics ```bash # Container logs (if Docker) docker compose logs --tail 50 {service} # Resource usage docker stats --no-stream # Docker htop # Bare metal # Disk usage df -h # System docker system df # Docker # Network netstat -tlnp # Listening ports curl -I http://localhost:{port} # Connectivity ``` ## Common Issues | Symptom | Check | Solution | |---------|-------|----------| | Service not responding | Process running? Port open? | Restart service | | Slow responses | Resource usage, connections | Scale or optimize | | Connection refused | Network, firewall, port | Check config | | Out of memory | `free -h`, container limits | Increase limits | ## Automated Health Check Run the bundled script for a JSON health report: ```bash python3 ${CLAUDE_SKILL_DIR}/scripts/health_check.py http://localhost:8000 ``` ## Health Report Format ```yaml services: {service-name}: status: healthy|degraded|down uptime: Xd Xh cpu: X% memory: XMB notes: "any issues" ``` ## Rules - **MUST** report measured values — never mark a service healthy without a successful probe - **NEVER** restart a degraded service without the user's explicit go-ahead - **CRITICAL**: separate liveness (process up) from readiness (accepting traffic) in the report - **MANDATORY**: if a health endpoint times out, classify as `degraded`, not `healthy` ## Gotchas - `docker compose ps` shows `Up` even when a container is **crash-looping** via restart policy — look at the `STATUS` column for `(unhealthy)` or `Restarting` rather than trusting "Up" alone. - Many `/health` endpoints return 200 as long as the web server answers, even when the DB connection is down. If the service exposes a `/ready` or `/healthz?deep=true` endpoint, prefer it — shallow health is a lie. - `pg_isready` reports success the moment Postgres accepts TCP, which happens seconds before the DB is actually query-ready after a restart. Chain it with a trivial `SELECT 1`. - `docker stats --no-stream` needs cgroups v2 access; on older hosts or LXC containers it returns 0% CPU/memory silently instead of erroring. Verify at least one non-zero value before trusting the report. ## When NOT to Use - To debug a specific failing service — use `/debug` after the health check narrows it down - For performance bottlenecks — use `/performance-profiling` - For a production incident with page/alert — use `/workflow incident-response` - For CI pipeline status — use `/ci`