code: def _parse_file():
      
      file_name = path.join(
          path.abspath(path.dirname(path.dirname(__file__))), 'config.json'
      )
      logger.info('loading configuration from file: %r', file_name)
      try:
          data = _read_file(file_name)
      except FileNotFoundError:
          logger.error('no configuration available, set FLASH_CONFIG or '
                       'provide config.json')
          exit()
      for service in data.get('services', []):
          for key, val in service.items():
              if isinstance(val, str) and re.match(r'^\$[A-Z_]+$', val):
                  env_val = getenv(val[1:])
                  if env_val is None:
                      logger.warning('environment variable %r not found', val[1:])
                  service[key] = env_val or val
      return data
docs: Parse the config from a file.
  
      Note:
        Assumes any value that ``"$LOOKS_LIKE_THIS"`` in a service
        definition refers to an environment variable, and attempts to get
        it accordingly.