Cleaning up Docker resources

In good old days, we used to write scripts to cleanup stale Docker containers, images, volumes, etc. Docker Engine 1.25 provided a welcome change on this. Now, there’s a relatively straightforward way to cleanup unused resources using the following command.

docker system prune

With this single command, you can remove all stopped containers, unused networks, dangling images, and build cache.

Even more importantly, prune is also available for other resource commands.

1docker container prune  # removes all stopped containers
2docker image prune      # removes unused images
3docker network prune    # removes all unused networks
4docker volume prune     # removes all unused local volumes
5docker builder prune    # removes build cache

There are also a couple of useful flags available:

• --all, -a removes all unused images and build cache (not merely dangling ones)
• --filter provides filtering capabilities by label or timestamp. (e.g., --filter "label!=latest", --filter "until=24h"). You can pass multiple filters.
• --force, -f executes the command without any confirmation prompt

You can read more about these commands in system, container, image, network, volume and builder references.