Basic script to detect and update active Docker container images

update_docker_images.sh

docker ps -aq > docker_ids.txt

while read CONTAINER
  do
    docker inspect ${CONTAINER} |grep -v sha |grep Image |awk '{print $2}' |tr -d '",'
  done < docker_ids.txt > docker_images.txt

while read IMAGE
  do
    docker pull ${IMAGE}
  done < docker_images.txt