Tips

Cleanup

Docker absolutely loves hogging drive space.

1. Remove dangling (i.e. unattached) volumes

docker volume ls -qf dangling=true | xargs -n1 docker volume rm

2. Remove n largest images

# to check
docker image list | awk '{print $8 " " $1 " " $2 " " $3}' | sort -hr | head
# to remove
docker image list | awk '{print $8 " " $1 " " $2 " " $3}' | sort -h | head | cut -d' ' -f5 | xargs docker rmi

This is generally safe, since docker won't allow you to remove images it needs without -f.

2. Prune system

docker system prune --volumes

This does a lot of stuff - if you are using btrfs and your docker subvolumes dir is absurdly bloated, it will help clean it up. Main things cleaned are build stages cache, networks, other stuff - it prints them with a confirmation.