docker-management

Check the container logs with docker logs NAME to see the crash reason, then run docker run -it --entrypoint /bin/sh IMAGE to explore the image interactively. Immediate exits usually mean the main process finished or crashed on startup.

Start with docker system df to see what consumes space, then run targeted cleanup: docker container prune for stopped containers, docker image prune for dangling images, and docker volume prune for unused volumes. Avoid docker system prune -a --volumes unless you confirm data loss is acceptable.

docker run starts a single container with inline flags, while docker compose up starts a multi-service stack defined in a compose.yml file with networking, dependencies, and healthchecks. Use Compose when services need to communicate, such as an API with its database.

The application inside the container is likely binding to 127.0.0.1 instead of 0.0.0.0, making it unreachable through port mapping. Verify the -p host:container flag is set and reconfigure the app to listen on all interfaces.

Use multi-stage builds to separate build tools from the runtime, pick slim or alpine base images like python:3.12-slim, combine RUN commands to reduce layers, and add a .dockerignore file excluding node_modules and .git.

No additional dependencies are required beyond Docker Engine with Compose v2, which ships with modern Docker installations. The user must be in the docker group or use sudo to run commands.