Stop all instances (Up)
$ sudo docker rm $(sudo docker ps -a | grep Up | awk '{print $1}')
Remove all instances stoped (Exited)
$sudo docker rm $(sudo docker ps -a | grep Exited | awk '{print $1}')
Remove empty instances (none)
$sudo docker rmi -f $(sudo docker images | grep '<none>'| awk '{print $3}')
Remove all images except ubuntu image.
$sudo docker rmi -f $(sudo docker images | grep -v 'ubuntu' | grep -v 'IMAGE'| awk '{print $3}')