When running Docker you pull down images. Those images can take up quite a bit of space. After tagging / retagging / untagging you can end up with dangling containers. So a bit of house keeping needs to be done.
The following command line will get rid of the so-called dangling containers:
docker mi $(docker images -q -f "dangling=true")
For bash users the following alias will come in handy
alias docker-scrub='docker mi $(docker images -q -f "dangling=true")'
Posted August 24, 2016