Delete useless Docker image containers and volumes

docker_clean.sh

#!/bin/bash
# from Kitware Jan 2017 newsletter
# remove dead and exited containers
docker ps --filter status=dead --filter status=exited -aq \
   | xargs -r docker rm -v

# remove unused images
docker images --no-trunc | grep  '<none>' \
   | awk '{print $3 }' \
   | xargs -r docker rmi

# remove unused volumes
docker volume ls -qf dangling=true \
   | xargs -r docker volume rm