code: def monitor_key_exists(service, key):
      
      try:
          check_call(
              ['ceph', '--id', service,
               'config-key', 'exists', str(key)])
          # I can return true here regardless because Ceph returns
          # ENOENT if the key wasn't found
          return True
      except CalledProcessError as e:
          if e.returncode == errno.ENOENT:
              return False
          else:
              log("Unknown error from ceph config-get exists: {} {}".format(
                  e.returncode, e.output))
              raise
docs: Searches for the existence of a 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 True if the key exists, False if not and raises an
       exception if an unknown error occurs. :raise: CalledProcessError if
       an unknown error occurs