CoreBeginner

Docker CLI Cheatsheet

The core docker command for managing containers, images, and the local engine.

What it is

Use the Docker CLI for day-to-day work with containers and images: running workloads, inspecting state, viewing logs, cleaning up disk, and debugging.

Installation

Ships with Docker Desktop and Docker Engine. Verify with docker version and docker info.

Quick start

docker run --rm -it alpine sh

Start an interactive throwaway container.

docker ps -a

List all containers, including stopped ones.

docker logs -f <container>

Tail logs from a running container.

docker exec -it <container> sh

Open a shell inside a running container.

docker system prune

Reclaim disk by removing unused data.

Common commands

Task	Command	Description
Show versions	`docker version`	Prints versions of the CLI and engine.
System info	`docker info`	Engine, storage driver, plugins, resources.
Run a container	`docker run <image>`	Create and start a container from an image.
List running	`docker ps`	Add -a to include stopped ones.
Stop a container	`docker stop <container>`	Sends SIGTERM, then SIGKILL after timeout.
Remove a container	`docker rm <container>`	Use -f to force-remove running ones.
List images	`docker images`	Local image cache.
Remove an image	`docker rmi <image>`	Fails if a container still references it.
View logs	`docker logs <container>`	Add -f to follow, –tail N for last N lines.
Exec into container	`docker exec -it <container> sh`	Run a command in a running container.
Inspect object	`docker inspect <id>`	Low-level JSON for containers, images, networks.
Live stats	`docker stats`	CPU, memory, network, I/O per container.
Disk usage	`docker system df`	Space used by images, containers, volumes, build cache.
Prune unused data	`docker system prune`	Add –volumes to also remove unused volumes.

Useful flags

Flag	Example	Meaning
`-d, --detach`	`docker run -d nginx`	Run container in the background.
`-it`	`docker run -it alpine sh`	Interactive TTY for shells and REPLs.
`--rm`	`docker run --rm alpine echo hi`	Auto-remove container on exit.
`-p`	`docker run -p 8080:80 nginx`	Publish host:container port.
`-v`	`docker run -v $(pwd):/app node`	Bind-mount a host path into the container.
`-e`	`docker run -e NODE_ENV=prod app`	Set an environment variable.
`--name`	`docker run --name api app`	Assign a stable container name.
`--network`	`docker run --network host nginx`	Attach to a specific network.

Real-world examples

Run nginx, publish port 8080

docker run -d --name web -p 8080:80 nginx:alpine

Mount your project into a node container

docker run --rm -it -v "$(pwd)":/app -w /app node:20 npm test

Reclaim disk aggressively

docker system prune -af --volumes

Removes unused images, networks, build cache, and volumes. Irreversible.

Best practices

Pin image tags (e.g. nginx:1.27-alpine) instead of :latest in production.
Always set --name for long-lived containers so scripts can reference them.
Use --rm for one-shot commands to keep the host clean.
Treat containers as immutable: rebuild the image, don't exec to patch.
Run docker system df weekly; prune build cache before disk fills up.

Troubleshooting

Cannot connect to the Docker daemon

Start Docker Desktop / engine, then re-check.

docker info

Port is already allocated

Find and stop the conflicting container.

docker ps --filter publish=8080

Container exits immediately

Read the last logs to see why.

docker logs --tail 100 <container>

Related cheatsheets

Last reviewed: 2026-06-15