Essential Docker Commands: Cheat Sheet with Examples

Essential Docker Commands: Cheat Sheet with Examples

After installing Docker, most container management tasks are performed from the command line. In this cheat sheet, we will cover the most useful Docker commands for starting, stopping, and removing containers, working with images, viewing logs, managing networks and volumes, and monitoring resource usage.

If Docker is not installed yet, follow our “How to Install Docker on Ubuntu 24.04” guide first.

Check the Docker Version

To check the installed Docker version:

docker --version

To display detailed information about your Docker installation:

docker info

List Docker Containers

To display currently running containers:

docker ps

To display all containers, including stopped containers:

docker ps -a

The output includes information such as the container ID, image, command, status, exposed ports, and container name.

Run a Docker Container

The basic command for creating and starting a container is:

docker run IMAGE

For example, to run an Nginx container:

docker run nginx

To run the container in the background, use the -d option:

docker run -d nginx

You can also assign a name to the container:

docker run -d --name web nginx

Using container names makes administration easier because you do not have to remember container IDs.

Expose Container Ports

To make a service running inside a container accessible from the server, use the -p option.

For example:

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

The port mapping uses the following format:

HOST_PORT:CONTAINER_PORT

For example:

docker run -d -p 8080:80 nginx

In this case, Nginx listens on port 80 inside the container and can be accessed through port 8080 on the server.

Stop a Docker Container

To stop a running container:

docker stop web

You can also use the container ID:

docker stop CONTAINER_ID

Start a Stopped Container

To start an existing stopped container:

docker start web

Restart a Container

To restart a running container:

docker restart web

This command is useful after changing an application's configuration or when troubleshooting a container.

Remove a Docker Container

First, stop the container:

docker stop web

Then remove it:

docker rm web

To force the removal of a running container:

docker rm -f web

Use forced removal carefully because it immediately stops and removes the container.

View Docker Container Logs

To view a container's logs:

docker logs web

To follow the logs in real time:

docker logs -f web

To display only the last 100 lines:

docker logs --tail 100 web

You can combine these options:

docker logs --tail 100 -f web

This is especially useful when troubleshooting applications running inside Docker containers.

Execute Commands Inside a Container

To execute a command inside a running container:

docker exec web COMMAND

For example:

docker exec web nginx -v

To open an interactive Bash shell:

docker exec -it web bash

Some minimal Docker images do not include Bash. In this case, try:

docker exec -it web sh

To exit the container shell:

exit

Inspect a Docker Container

To display detailed information about a container:

docker inspect web

The output contains information about networking, IP addresses, mounted volumes, environment variables, ports, and other container settings.

Monitor Docker Container Resources

To monitor CPU, memory, network, and disk I/O usage:

docker stats

To monitor a specific container:

docker stats web

Press Ctrl + C to exit.

This command can be useful when checking resource consumption on a VPS or dedicated server.

Working with Docker Images

To list downloaded Docker images:

docker images

To download an image from a registry:

docker pull nginx

To download a specific image tag:

docker pull nginx:alpine

To remove an image:

docker rmi nginx

Docker may prevent an image from being removed if it is still used by an existing container.

Working with Docker Volumes

Docker volumes provide persistent storage for container data.

To list existing volumes:

docker volume ls

Create a new volume:

docker volume create app-data

Display information about a volume:

docker volume inspect app-data

Remove a volume:

docker volume rm app-data

Be careful when removing volumes. They may contain databases, application files, configuration data, or other important information.

Working with Docker Networks

To list Docker networks:

docker network ls

Create a network:

docker network create app-network

Inspect a network:

docker network inspect app-network

Remove a network:

docker network rm app-network

Custom Docker networks are especially useful when multiple containers need to communicate with each other.

Configure Automatic Container Restart

For applications running on a server, you may want containers to start automatically after a server reboot.

For example:

docker run -d \
  --name web \
  --restart unless-stopped \
  -p 80:80 \
  nginx

The following option:

--restart unless-stopped

instructs Docker to automatically restart the container unless it was manually stopped.

Check Docker Disk Usage

Docker images, containers, volumes, and build cache can consume a significant amount of disk space over time.

To check Docker disk usage:

docker system df

For more detailed information:

docker system df -v

Clean Up Unused Docker Resources

To remove unused containers, networks, dangling images, and build cache:

docker system prune

Docker will ask for confirmation before deleting the data.

For a more aggressive cleanup:

docker system prune -a

The -a option also removes unused images.

Before running cleanup commands on a production server, make sure the resources are no longer required.

Useful Docker Compose Commands

If your application uses Docker Compose, the following commands are commonly used.

Start the project:

docker compose up -d

List containers:

docker compose ps

View logs:

docker compose logs -f

Restart services:

docker compose restart

Stop services:

docker compose stop

Stop and remove project containers:

docker compose down

Download newer versions of the images:

docker compose pull

For more information, see our “How to Install Docker Compose on Ubuntu 24.04” guide.

Docker Commands Cheat Sheet

Here are some of the most useful Docker commands for everyday server administration.

List running containers:

docker ps

List all containers:

docker ps -a

Start a container:

docker start NAME

Stop a container:

docker stop NAME

Restart a container:

docker restart NAME

View container logs:

docker logs -f NAME

Open a Bash shell inside a container:

docker exec -it NAME bash

List Docker images:

docker images

Monitor resource usage:

docker stats

Check Docker disk usage:

docker system df

Conclusion

For everyday Docker administration, you only need to remember a relatively small number of commands. Commands such as docker ps, docker logs, docker exec, docker stop, docker restart, and docker compose cover many common container management tasks.

Once you understand these commands, you can easily manage applications running in Docker containers, troubleshoot problems, monitor resource usage, and maintain Docker environments on VPS and dedicated servers.

If you are new to Docker, start with our “How to Install Docker on Ubuntu 24.04” guide and then continue with “How to Install Docker Compose on Ubuntu 24.04.”