prune unused docker images

prune.sh

#!/bin/bash

# Get in use image tags
docker ps | grep -v 'IMAGE' | awk '{ print $2}' > tags-inuse.txt

# Get all images with tags, combine the image and tag keep the id
docker images -a | grep -v 'REPOSITORY' | grep -v '^<none>' | awk '{print $1":"$2"\t"$3}' > tags-full.txt

# Remove the in-use tags from the full list
grep -v -f tags-inuse.txt tags-full.txt > tags-prune-list.txt

while read l; do
  echo "** removing image $l"
  # Remove the tags from the images
  echo "$l" | awk '{print $1}' | xargs docker rmi
  # be kind
  sleep 1
done < tags-prune-list.txt

echo "fin."