Pull down the latest version of docker images

update-docker-images.sh

#!/bin/sh

# Pull down the latest docker images
#
# "docker-compose pull" will pull down the latest images but will not do it
# intelligently as it will attempt to update things multiple times if they
# are dependencies of several services (eg. mysql).
#
# It will also only work on the current directory.
#
# This script will:
# - Only attempt to update an image *once*.
# - Process all the docker-compose.yml files in the given directory and
#   all subdirectories.

if [ "$#" -ne 1 ] || ! [ -d "$1" ]; then
  echo "Usage: $0 [directory]" >&2
  exit 1
fi

cd $1

# Find all non-vendor docker-compose.yml files.
files=$(find . -name docker-compose.yml | egrep -v 'vendor|node_modules')

# Pull out the images used
# Have to filter out "image: {ecr}/{repo}:{tag}"
images=$(grep -h image: $files | grep -v '{' | awk '{ print $2 }' | sort | uniq)

# Now do the update
for image in $images
do
  docker pull $image
done