func Save(ctx context.Context, lg *zap.Logger, cfg clientv3.Config, dbPath string) error
Save fetches snapshot from remote etcd server and saves data to target path. If the context "ctx" is canceled or timed out, snapshot save stream will error out (e.g. context.Canceled, context.DeadlineExceeded). Make sure to specify only one endpoint in client configuration. Snapshot API must be requested to a selected node, and saved snapshot is the point-in-time state of the selected node.