clientv3: fix client balancer with gRPC v1.7

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

clientv3/integration/util.go

@@ -0,0 +1,35 @@
+// Copyright 2017 The etcd Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package integration
+
+import (
+	"testing"
+	"time"
+
+	"github.com/coreos/etcd/clientv3"
+
+	"golang.org/x/net/context"
+)
+
+// mustWaitPinReady waits up to 3-second until connection is up (pin endpoint).
+// Fatal on time-out.
+func mustWaitPinReady(t *testing.T, cli *clientv3.Client) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	_, err := cli.Get(ctx, "foo")
+	cancel()
+	if err != nil {
+		t.Fatal(err)
+	}
+}