code: def _render(roster_file, **kwargs):
      
      renderers = salt.loader.render(__opts__, {})
      domain = __opts__.get('roster_domain', '')
      try:
          result = salt.template.compile_template(roster_file,
                                                  renderers,
                                                  __opts__['renderer'],
                                                  __opts__['renderer_blacklist'],
                                                  __opts__['renderer_whitelist'],
                                                  mask_value='passw*',
                                                  **kwargs)
          result.setdefault('host', '{}.{}'.format(os.path.basename(roster_file), domain))
          return result
      except:  # pylint: disable=W0702
          log.warning('Unable to render roster file "%s".', roster_file, exc_info=True)
          return {}
docs: Render the roster file