code: def docker_image_ids(broker):
          
          images = broker[DefaultSpecs.docker_list_images]
          try:
              result = set()
              for l in images.content[1:]:
                  result.add(l.split(None)[3].strip())
          except:
              raise ContentException("No docker images.")
          if result:
              return list(result)
          raise ContentException("No docker images.")
docs: Command: docker_image_ids