save-docker-images.sh

docker images | tail --lines=+2 | while read LINE ; do
  REPO=`echo ${LINE} | awk '{print $1}'`
  TAG=`echo ${LINE} | awk '{print $2}'`
  ID=`echo ${LINE} | awk '{print $3}'`
  # Replace '/' characters in REPO with '_'
  FILENAME=${REPO//\//_}__${TAG}__${ID}.tar
  IMAGE=${REPO}:${TAG}

save some images

for substr in 'your-image-tag1' 'your-image-tag2'; do
    if [ -z "${IMAGE##*$substr*}" ] ;then
      echo "Saving docker image ${REPO}:${TAG} as ${FILENAME} ..."
      docker save ${REPO}:${TAG} > ${FILENAME}
      break
    fi
  done
done