2 examples for docker rmi

  # Remove all untagged docker images.
# - docker rmi - remove image
#   - docker images -a - show all images
#   - grep '^' - filter the list down to those entries with no
#     value in the Repository column
#   - awk '{print $3}') - show only the image IDs from the output,
#     feeding it back to `docker rmi`
docker rmi $(docker images -a | grep '^' | awk '{print $3}')
        

  # Delete all images
docker rmi $(docker images -q)