Free up space

$ docker system prune

Removes:

• all stopped containers
• all networks not used by at least one container
• all dangling images
• all build cache

$ docker system prune -a --volumes

In addition to above, removes:

• all volumes not used by at least one container
• all images without at least one container associated to them

More: https://docs.docker.com/engine/reference/commandline/system_prune/