Update containers in docker-compose file

update.sh

#!/bin/bash

# Updates containers in a docker-compose file. If passed a name, it will
# just update that container. If no argument is given, it will update
# all the containers in the file. It must be run in a directory where a
# docker-compose command will work and see it's yaml config file.
#
# WARNING: It does remove and create the container, so be careful if you
# care about state that's not saved outside of the container.
#
# Requires docker-compose 1.6+ (Feb 4, 2016)

CONTAINER_NAME=$1

update_container() {
  echo "Updating: $1"

  PULL_RESULT=`docker-compose pull $1 | grep "Downloaded newer image"`
  if [[ ! $? -eq 0 ]]; then
    echo "Container $1 is up to date."
  else
    docker-compose stop $1
    docker-compose rm -f $1
    docker-compose up -d $1
  fi
}

if [[ -z "$CONTAINER_NAME" ]]; then
  docker-compose config --services | while read line; do
    update_container $line
  done
else
  update_container $CONTAINER_NAME
fi