code: def _get_file_auth_config():
      '''
      Setup defaults and check configuration variables for auth backends
      '''
  
      config = {
          'filetype': 'text',
          'hashtype': 'plaintext',
          'field_separator': ':',
          'username_field': 1,
          'password_field': 2,
      }
  
      for opt in __opts__['external_auth'][__virtualname__]:
          if opt.startswith('^'):
              config[opt[1:]] = __opts__['external_auth'][__virtualname__][opt]
  
      if 'filename' not in config:
          log.error('salt.auth.file: An authentication file must be specified '
                    'via external_auth:file:^filename')
          return False
  
      if not os.path.exists(config['filename']):
          log.error('salt.auth.file: The configured external_auth:file:^filename (%s)'
                    'does not exist on the filesystem', config['filename'])
          return False
  
      config['username_field'] = int(config['username_field'])
      config['password_field'] = int(config['password_field'])
  
      return confif _get_file_auth_config():
      '''
      Setup defaults and check configuration variables for auth backends
      '''
  
      config = {
          'filetype': 'text',
          'hashtype': 'plaintext',
          'field_separator': ':',
          'username_field': 1,
          'password_field': 2,
      }
  
      for opt in __opts__['external_auth'][__virtualname__]:
          if opt.startswith('^'):
              config[opt[1:]] = __opts__['external_auth'][__virtualname__][opt]
  
      if 'filename' not in config:
          log.error('salt.auth.file: An authentication file must be specified '
                    'via external_auth:file:^filename')
          return False
  
      if not os.path.exists(config['filename']):
          log.error('salt.auth.file: The configured external_auth:file:^filename (%s)'
                    'does not exist on the filesystem', config['filename'])
          return False
  
      config['username_field'] = int(config['username_field'])
      config['password_field'] = int(config['password_field'])
  
      return config
docs: Setup defaults and check configuration variables for auth backends