docs: def _get_existing_conf(config):
      """
      Read existing local.conf and strip out service id and client secret
      :param config: Location of config files
      :param lines of existing config (excluding service id and client secret)
      """
      try:
          with open(os.path.join(config, 'local.conf'), 'r') as f:
              lines = [line for line in f.readlines()
                       if not (line.startswith('service_id') or line.startswith('client_secret'))]
      except IOError:
          lines = []
      return lines