code: def _get_local_image_id(docker_binary, docker_tag):
      
      cmd = [docker_binary, "images", "-q", docker_tag]
      image_id_b = check_output(cmd)
      image_id = image_id_b.decode('utf-8').strip()
      if not image_id:
          raise RuntimeError('Unable to find docker image id matching with tag {}'.format(docker_tag))
      return image_id
docs: Get the image id of the local docker layer with the passed tag
      :param docker_tag: docker tag
      :return: Image id as string or None if tag does not exist