channelz: re-add target and state (#7042)

Author: dfawley

clientconn.go

@@ -529,6 +529,7 @@ func (csm *connectivityStateManager) updateState(state connectivity.State) {
 		return
 	}
 	csm.state = state
+	csm.channelz.ChannelMetrics.State.Store(&state)
 	csm.pubSub.Publish(state)
 
 	channelz.Infof(logger, csm.channelz, "Channel Connectivity change to %v", state)

internal/channelz/funcs.go

@@ -108,13 +108,13 @@ func GetServer(id int64) *Server {
 }
 
 // RegisterChannel registers the given channel c in the channelz database with
-// ref as its reference name, and adds it to the child list of its parent.
-// parent == nil means no parent.
+// target as its target and reference name, and adds it to the child list of its
+// parent.  parent == nil means no parent.
 //
 // Returns a unique channelz identifier assigned to this channel.
 //
 // If channelz is not turned ON, the channelz database is not mutated.
-func RegisterChannel(parent *Channel, ref string) *Channel {
+func RegisterChannel(parent *Channel, target string) *Channel {
 	id := IDGen.genID()
 
 	if !IsOn() {
@@ -125,12 +125,13 @@ func RegisterChannel(parent *Channel, ref string) *Channel {
 
 	cn := &Channel{
 		ID:          id,
-		RefName:     ref,
+		RefName:     target,
 		nestedChans: make(map[int64]string),
 		subChans:    make(map[int64]string),
 		Parent:      parent,
 		trace:       &ChannelTrace{CreationTime: time.Now(), Events: make([]*traceEvent, 0, getMaxTraceEntry())},
 	}
+	cn.ChannelMetrics.Target.Store(&target)
 	db.addChannel(id, cn, isTopChannel, cn.getParentID())
 	return cn
 }

test/channelz_test.go

@@ -100,6 +100,37 @@ func (s) TestCZServerRegistrationAndDeletion(t *testing.T) {
 	}
 }
 
+func (s) TestCZGetChannel(t *testing.T) {
+	e := tcpClearRREnv
+	e.balancer = ""
+	te := newTest(t, e)
+	te.startServer(&testServer{security: e.security})
+	r := manual.NewBuilderWithScheme("whatever")
+	addrs := []resolver.Address{{Addr: te.srvAddr}}
+	r.InitialState(resolver.State{Addresses: addrs})
+	te.resolverScheme = r.Scheme()
+	te.clientConn(grpc.WithResolvers(r))
+	defer te.tearDown()
+	if err := verifyResultWithDelay(func() (bool, error) {
+		tcs, _ := channelz.GetTopChannels(0, 0)
+		if len(tcs) != 1 {
+			return false, fmt.Errorf("there should only be one top channel, not %d", len(tcs))
+		}
+		target := tcs[0].ChannelMetrics.Target.Load()
+		wantTarget := "whatever:///" + te.srvAddr
+		if target == nil || *target != wantTarget {
+			return false, fmt.Errorf("Got channelz target=%v; want %q", target, wantTarget)
+		}
+		state := tcs[0].ChannelMetrics.State.Load()
+		if state == nil || *state != connectivity.Ready {
+			return false, fmt.Errorf("Got channelz state=%v; want %q", state, connectivity.Ready)
+		}
+		return true, nil
+	}); err != nil {
+		t.Fatal(err)
+	}
+}
+
 func (s) TestCZGetServer(t *testing.T) {
 	e := tcpClearRREnv
 	te := newTest(t, e)