#!/bin/bash
#
# Keeps latest X tags of every Docker Image

KEEP_IMAGES_BACK=2

echo Retrieving local images available

# get all images
IMAGES=$(docker images | sort | awk '{print $1}' | uniq | grep -v "<none>")

echo Cleaning old tags...

for i in $IMAGES; do
  COUNT=$(docker images | grep "$i " | wc -l)

  if [[ $COUNT -ge 3 ]]; then
    echo IMAGE $i has $COUNT tags
    docker images | grep "$i " | tail -$(($COUNT-$KEEP_IMAGES_BACK)) | awk '{print $1 ":" $2}' | xargs docker rmi
  fi
done