Docker Compose

Use this skill for the whole Compose lifecycle: model the application, validate the resolved configuration, start or update services, inspect runtime state, and diagnose failures. Prefer the current Compose Specification. Do not add a top-level version key to new files: it is obsolete and does not select a schema.

Operating loop

1. Discover the Compose file(s), project directory, env files, profiles, external resources, and whether the task is development, CI, staging, or production.
2. Model the application with services, named volumes for durable state, explicit networks for isolation, secrets for sensitive files, and profiles for optional services.
3. Resolve before running:

   docker compose -f compose.yaml config --quiet
   docker compose -f compose.yaml config
   docker compose -f compose.yaml config --services
   

4. Operate with the narrowest command: up -d SERVICE, restart SERVICE, run --rm SERVICE COMMAND, or exec SERVICE COMMAND. Avoid down -v unless data deletion is intentional and confirmed.
5. Verify with ps, health status, logs, an in-container check, and the externally published endpoint where applicable.
6. Diagnose in order: resolved model → container state → logs → healthcheck → network membership/DNS → mounts/permissions → image/build architecture → host resources.

Decision rules