Docker image cleaner
The long missing command to clean up all docker images that are not used by any container.
This command is available as docker image
docker run --rm -v /var/run/docker.sock:/var/run/docker.sock bobrik/image-cleaner
-dry-run to the end if you want to see what is going to be deleted.
If you want to keep some images, use
-exclude image:tag[,image:tag] flag.