Docker Commands Cheat Sheet

Common Docker commands: run, ps, build, compose, exec, logs, volume and more, with notes for everyday container work.

How It Works

Docker packages an app with its dependencies as an image, and runs an instance of that image as a container. An image is built from stacked read-only layers (cached and reused); the container adds one writable layer on top, so startup is fast and isolation is strong.

The core lifecycle: build creates an image from a Dockerfile, run starts a container, ps lists running ones, exec runs a command inside, rm/rmi clean up. Mounting a host directory as a volume keeps data alive after the container is removed.

Command	Description
docker --version	Show the Docker client version
docker version	Show client and server versions
docker info	Display system-wide info
docker login	Log in to a registry
docker pull	Pull an image from a registry
docker push	Push an image to a registry
docker images	List local images (-a all)
docker rmi	Remove an image (-f force)
docker build	Build from a Dockerfile (-t tag)
docker run	Run a container (-d detach / -p port)
docker ps	List running containers (-a all)
docker stop	Stop a running container
docker start	Start a stopped container
docker restart	Restart a container
docker rm	Remove a container (-f force / -v volume)
docker exec	Run a command in a container (-it)
docker logs	Fetch container logs (-f follow)
docker cp	Copy files between container and host
docker inspect	Return low-level JSON info
docker top	Show running processes in a container
docker compose up	Start compose services (-d)
docker compose down	Stop and remove compose resources
docker compose build	Build images in compose
docker network ls	List Docker networks
docker volume ls	List volumes
docker system prune	Remove unused data (-a all)
docker stats	Live resource usage stats

Frequently Asked Questions

What is the difference between docker run and docker create?

`docker create` only creates a container without starting it; `docker run` is create + start, launching the main process immediately (in the foreground, or with `-d` detached).

How do I enter a running container?

Use `docker exec -it <container> /bin/sh` (or `/bin/bash`) for an interactive shell; add `--rm` to auto-clean the exec process on exit.

How do I see disk space used by containers?

`docker system df` shows overall image/container/volume usage; `docker ps -s` shows each container's writable size; clean up with `docker system prune -a`.

How do I save a container's changes as a new image?

Use `docker commit <container> <new-image>` to freeze the current state, but writing a Dockerfile is preferred for reproducible, versioned builds.