make TestEtcdWithHangLeaderEnableCheck stable

Signed-off-by: Ryan Leung <[email protected]>

pkg/utils/etcdutil/etcdutil_test.go

@@ -300,11 +300,10 @@ func checkEtcdWithHangLeader(t *testing.T) error {
 	etcd2 := MustAddEtcdMember(t, &cfg1, client1)
 	defer etcd2.Close()
 	checkMembers(re, client1, []*embed.Etcd{etcd1, etcd2})
-	time.Sleep(1 * time.Second) // wait for etcd client sync endpoints
 
 	// Hang the etcd1 and wait for the client to connect to etcd2.
 	enableDiscard.Store(true)
-	time.Sleep(time.Second)
+	time.Sleep(3 * time.Second)
 	_, err = EtcdKVGet(client1, "test/key1")
 	return err
 }
@@ -366,7 +365,8 @@ func ioCopy(ctx context.Context, dst io.Writer, src io.Reader, enableDiscard *at
 			return nil
 		default:
 			if enableDiscard.Load() {
-				io.Copy(io.Discard, src)
+				_, err := io.Copy(io.Discard, src)
+				return err
 			}
 			readNum, errRead := src.Read(buffer)
 			if readNum > 0 {