code: def monitor_key_get(service, key):
      
      try:
          output = check_output(
              ['ceph', '--id', service,
               'config-key', 'get', str(key)]).decode('UTF-8')
          return output
      except CalledProcessError as e:
          log("Monitor config-key get failed with message: {}".format(
              e.output))
          return None
docs: Gets the value of an existing key in the monitor cluster.
      :param service: six.string_types. The Ceph user name to run the command under
      :param key: six.string_types.  The key to search for.
      :return: Returns the value of that key or None if not found.