def save_configuration_files(self, check_custom_bootstrap: bool = False) -> bool:
        """
            copy postgresql.conf to postgresql.conf.backup to be able to retrieve configuration files
            - originally stored as symlinks, those are normally skipped by pg_basebackup
            - in case of WAL-E basebackup (see http://comments.gmane.org/gmane.comp.db.postgresql.wal-e/239)
        """
        if not (check_custom_bootstrap and self._postgresql.bootstrap.running_custom_bootstrap):
            try:
                for f in self._configuration_to_save:
                    config_file = os.path.join(self._config_dir, f)
                    backup_file = os.path.join(self._postgresql.data_dir, f + '.backup')
                    if os.path.isfile(config_file):
                        shutil.copy(config_file, backup_file)
                        self.set_file_permissions(backup_file)
            except IOError:
                logger.exception('unable to create backup copies of configuration files')
        return True

            copy postgresql.conf to postgresql.conf.backup to be able to retrieve configuration files
            - originally stored as symlinks, those are normally skipped by pg_basebackup
            - in case of WAL-E basebackup (see http://comments.gmane.org/gmane.comp.db.postgresql.wal-e/239)
        
patroni/postgresql/config.py