'Check if a v1 configuration file exists and upgrade it if necessary.
After upgrade, the v1 configuration file is retained with an archived
file name, which ensures the data is not lost but we do not override
a newer configuration version next time the service starts.
:param bytes file_name: The expected file name of a version 1
configuration.
:param bytes archive_name: The file name to which a version 1
configuration should be moved after it has been processed.'

def _process_v1_config(self, file_name, archive_name):

    v1_config_path = self._path.child(file_name)
    v1_archived_path = self._path.child(archive_name)
    if v1_config_path.exists():
        v1_json = v1_config_path.getContent()
        with _LOG_UPGRADE(self.logger, configuration=v1_json, source_version=1, target_version=_CONFIG_VERSION):
            updated_json = migrate_configuration(1, _CONFIG_VERSION, v1_json, ConfigurationMigration)
            self._config_path.setContent(updated_json)
            v1_config_path.moveTo(v1_archived_path)
