docker-management

Check the container logs with docker logs NAME to see the error, then try running the image interactively with docker run -it --entrypoint /bin/sh IMAGE to inspect the environment. The main process usually crashed or finished, so verify your CMD or ENTRYPOINT instruction.

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 named volumes can be deleted.

docker run starts a single container with CLI flags, while docker compose up starts multi-service stacks defined in a compose.yml file with networking, dependencies, and healthchecks configured declaratively. Use Compose for applications with multiple interconnected services.

The application inside the container is likely binding to 127.0.0.1 instead of 0.0.0.0, making it unreachable from outside. Also verify the port mapping with docker port NAME and ensure you used -p hostPort:containerPort when starting the container.

Use multi-stage builds to separate build and runtime environments, choose slim or alpine base images like python:3.12-slim, combine RUN commands to reduce layers, and add a .dockerignore file to exclude node_modules, .git, and other unnecessary files.

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