how to clean up docker overlay directory?

From our side we used:

sudo docker system prune -a -f

Which saved me 3Go!

We also used the famous commands:

sudo docker rm -v $(sudo docker ps -a -q -f status=exited)
sudo docker rmi -f  $(sudo docker images -f "dangling=true" -q)
docker volume ls -qf dangling=true | xargs -r docker volume rm

We put that on cron to manage a little bit more efficently our disk space.

Reference: https://forums.docker.com/t/some-way-to-clean-up-identify-contents-of-var-lib-docker-overlay/30604/4

Here's the hacky way I'm doing this right now. I'm not going to accept it as an answer because I'm hoping there's a better way.

# delete old docker processes
docker rm `docker ps -a | grep Exited | awk '{print $1 }'`
  ignore_errors: true

# delete old images. will complain about still-in-use images.
docker rmi `docker images -aq`