Docker cheat sheet

This is a living document of useful commands for maintaining and using Docker, and should function as a handy reference for developers and DevOps engineers.

I'll kick off this Docker cheat sheet with cleaning up Docker images, let's get started.

Cleaning up Docker images

If you update your Docker container images regularly using something like watchtower, you might have dangling images which are out-of-date and no longer associated with some of your running containers.

So why not use docker image prune to reclaim that valuable disk space. For example, running this command on my Raspberry Pi shaved off about 9.66Gb of disk usage.

As a bonus, you can save some additional space using docker image prune --all, which removes all unused Docker images.

Restarting all containers

Sometimes you want to restart all your containers at once, such as after you've pulled the latest images for your containers.

To do this, use docker restart $(docker ps -q), this command instructs Docker to restart all containers using the container ids which are returned from docker ps -q.

Stopping all containers

Need to stop all containers? Simply use docker stop $(docker ps -q). As above, this uses the container ids from docker ps to stop each running container.