def _init_driver(self, shard_id): """Given a shard name, returns a storage driver. :param shard_id: The name of a shard. :type shard_id: six.text_type :returns: a storage driver :rtype: marconi.queues.storage.base.DataDriver """ shard = self._shards_ctrl.get(shard_id, detailed=True) conf = utils.dynamic_conf(shard['uri'], shard['options']) return utils.load_storage_driver(conf, self._cache)