add script caching images from docker-compose.yml

Author: g-pavlik

load_images.sh

@@ -0,0 +1,25 @@
+#!/bin/bash 
+
+## this simple script checks if you have docker images stored as tar archives
+## if so - it will load it from there, if not - it will pull and save it there
+## useful for circle images caching: 
+##    https://circleci.com/docs/docker#caching-docker-layers
+
+cache_dir=~/cache_docker_images/
+mkdir -p $cache_dir
+for image in `cat docker-compose.yml | grep 'image:' | grep -o ' [^ ]*$'`; do
+  filename=$( echo "$image" | sed -r 's/\//_/g' )
+
+  image_path="$cache_dir""$filename"".tar"
+
+  if [[ -e $image_path ]]; then 
+   echo "Image $image exists in $image_path, loading..."
+    docker load -i $image_path 
+  else 
+    echo "Image $image not found, pulling..."
+    docker pull $image
+    echo "saving $image > $image_path"
+    docker save $image > $image_path
+  fi
+
+done