new_contents: #!/usr/bin/env python
  
  import argparse
  import atexit
  import logging
  
  DEFAULT_DOCKER_BASE_URL = 'unix://var/run/docker.sock'
  DOCKER_BASE_URL_HELP =  ('Refers to the protocol+hostname+port where the '
      'Docker server is hosted. Defaults to %s') % DEFAULT_DOCKER_BASE_URL
  DEFAULT_DOCKER_API_VERSION = 'auto'
  DOCKER_API_VERSION_HELP =  ('The version of the API the client will use. '
      'Defaults to use the API version provided by the server')
  DEFAULT_DOCKER_HTTP_TIMEOUT = 5
  DOCKER_HTTP_TIMEOUT_HELP =  ('The HTTP request timeout, in seconds. '
      'Defaults to %d secs') % DEFAULT_DOCKER_HTTP_TIMEOUT
  
  def _exit():
      logging.shutdown()
  
  def main():
      atexit.register(func=_exit)
      parser = argparse.ArgumentParser(description='Clean old docker images')
      parser.add_argument('--debug', help='debug mode', action='store_true')
      parser.add_argument('--base-url', help=DOCKER_BASE_URL_HELP, default=DEFAULT_DOCKER_BASE_URL)
      parser.add_argument('--api-version', help=DOCKER_API_VERSION_HELP, default=DEFAULT_DOCKER_API_VERSION)
      parser.add_argument('--http-timeout', help=DOCKER_HTTP_TIMEOUT_HELP, default=DEFAULT_DOCKER_HTTP_TIMEOUT, type=int)
      args = parser.parse_args()
      if args.debug:
          logging.basicConfig(level=logging.DEBUG)
  
  if __name__ == '__main__':
      main()
  
subject: Add docker client options to argparse