docker-debug-containerslisted

# Docker Debug Containers Use this skill when containers fail to start, restart repeatedly, or behave unexpectedly. ## 1. Capture Container State Start with high-signal status output: ```sh docker ps -a --format 'table {{.Names}}\t{{.Image}}\t{{.Status}}\t{{.Ports}}' ``` Then inspect the target container: ```sh docker inspect <container> ``` Extract: - exit code, - restart count/policy, - health status, - mounted volumes, - network attachment. ## 2. Read Logs with Scope Get recent logs: ```sh docker logs --tail 200 <container> ``` If the issue is timing-sensitive, follow logs: ```sh docker logs -f <container> ``` Capture the first actionable error lines instead of dumping unfiltered output. ## 3. Run In-Container Checks Use `exec` for runtime validation: ```sh docker exec -it <container> sh ``` Check process health, config files, env values, connectivity, and required binaries. ## 4. Check Host and Resource Signals Use non-streaming stats for quick pressure checks: ```sh docker stats --no-stream ``` Investigate network/volume dependencies as needed: ```sh docker network inspect <network> docker volume inspect <volume> ``` ## 5. Provide Remediation Path Offer targeted next actions based on observed evidence: - config/env fixes, - image rebuilds, - dependency service startup ordering, - restart policy adjustments, - container recreate (`docker rm` + `docker run`/`docker compose up`) when safe and requested. ## 6. Return a Debug Report Return: - symptom