xdsdepmgr: add functionality for cluster subscription

internal/xds/resolver/cluster_specifier_plugin_test.go

@@ -126,7 +126,7 @@ func (s) TestResolverClusterSpecifierPlugin(t *testing.T) {
 		ClusterSpecifierPluginName:   "cspA",
 		ClusterSpecifierPluginConfig: testutils.MarshalAny(t, &wrapperspb.StringValue{Value: "anything"}),
 	})}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, nil, nil)
 
 	stateCh, _, _ := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, bc)
 
@@ -171,7 +171,7 @@ func (s) TestResolverClusterSpecifierPlugin(t *testing.T) {
 		ClusterSpecifierPluginName:   "cspA",
 		ClusterSpecifierPluginConfig: testutils.MarshalAny(t, &wrapperspb.StringValue{Value: "changed"}),
 	})}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, nil, nil)
 
 	// Wait for an update from the resolver, and verify the service config.
 	wantSC = `
@@ -216,7 +216,7 @@ func (s) TestXDSResolverDelayedOnCommittedCSP(t *testing.T) {
 		ClusterSpecifierPluginName:   "cspA",
 		ClusterSpecifierPluginConfig: testutils.MarshalAny(t, &wrapperspb.StringValue{Value: "anythingA"}),
 	})}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, nil, nil)
 
 	stateCh, _, _ := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, bc)
 
@@ -265,7 +265,7 @@ func (s) TestXDSResolverDelayedOnCommittedCSP(t *testing.T) {
 		ClusterSpecifierPluginName:   "cspB",
 		ClusterSpecifierPluginConfig: testutils.MarshalAny(t, &wrapperspb.StringValue{Value: "anythingB"}),
 	})}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, nil, nil)
 
 	// Wait for an update from the resolver, and verify the service config.
 	wantSC = `

internal/xds/resolver/helpers_test.go

@@ -254,36 +254,21 @@ func setupManagementServerForTest(t *testing.T, nodeID string) (*e2e.ManagementS
 	return mgmtServer, listenerResourceNamesCh, routeConfigResourceNamesCh, bootstrapContents
 }
 
-// Spins up an xDS management server and configures it with a default listener
-// and route configuration resource. It also sets up an xDS bootstrap
-// configuration file that points to the above management server.
-func configureResourcesOnManagementServer(ctx context.Context, t *testing.T, mgmtServer *e2e.ManagementServer, nodeID string, listeners []*v3listenerpb.Listener, routes []*v3routepb.RouteConfiguration) {
+// Updates all resources on the given management server.
+func configureResources(ctx context.Context, t *testing.T, mgmtServer *e2e.ManagementServer, nodeID string, listeners []*v3listenerpb.Listener, routes []*v3routepb.RouteConfiguration, clusters []*v3clusterpb.Cluster, endpoints []*v3endpointpb.ClusterLoadAssignment) {
 	resources := e2e.UpdateOptions{
 		NodeID:         nodeID,
 		Listeners:      listeners,
 		Routes:         routes,
+		Clusters:       clusters,
+		Endpoints:      endpoints,
 		SkipValidation: true,
 	}
 	if err := mgmtServer.Update(ctx, resources); err != nil {
 		t.Fatal(err)
 	}
 }
 
-// Updates all the listener, route, cluster and endpoint configuration resources
-// on the given management server.
-func configureAllResourcesOnManagementServer(ctx context.Context, t *testing.T, mgmtServer *e2e.ManagementServer, nodeID string, listeners []*v3listenerpb.Listener, routes []*v3routepb.RouteConfiguration, clusters []*v3clusterpb.Cluster, endpoints []*v3endpointpb.ClusterLoadAssignment) {
-	resources := e2e.UpdateOptions{
-		NodeID:    nodeID,
-		Listeners: listeners,
-		Routes:    routes,
-		Clusters:  clusters,
-		Endpoints: endpoints,
-	}
-	if err := mgmtServer.Update(ctx, resources); err != nil {
-		t.Fatal(err)
-	}
-}
-
 // waitForResourceNames waits for the wantNames to be pushed on to namesCh.
 // Fails the test by calling t.Fatal if the context expires before that.
 func waitForResourceNames(ctx context.Context, t *testing.T, namesCh chan []string, wantNames []string) {

internal/xds/resolver/watch_service_test.go

@@ -101,7 +101,7 @@ func (s) TestServiceWatch_ListenerPointsToNewRouteConfiguration(t *testing.T) {
 
 	// Update the management server with the new route configuration resource.
 	resources.Routes = append(resources.Routes, e2e.DefaultRouteConfig(newTestRouteConfigName, defaultTestServiceName, resources.Clusters[0].Name))
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, resources.Listeners, resources.Routes)
+	configureResources(ctx, t, mgmtServer, nodeID, resources.Listeners, resources.Routes, nil, nil)
 
 	// Ensure update from the resolver.
 	verifyUpdateFromResolver(ctx, t, stateCh, wantServiceConfig(resources.Clusters[0].Name))
@@ -169,15 +169,15 @@ func (s) TestServiceWatch_ListenerPointsToInlineRouteConfiguration(t *testing.T)
 			}},
 		}},
 	}}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, resources.Listeners, nil)
+	configureResources(ctx, t, mgmtServer, nodeID, resources.Listeners, nil, nil, nil)
 
 	// Verify that the old route configuration is not requested anymore.
 	waitForResourceNames(ctx, t, routeCfgCh, []string{})
 	verifyUpdateFromResolver(ctx, t, stateCh, wantServiceConfig(resources.Clusters[0].Name))
 
 	// Update listener back to contain a route configuration name.
 	resources.Listeners = []*v3listenerpb.Listener{e2e.DefaultClientListener(defaultTestServiceName, resources.Routes[0].Name)}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, resources.Listeners, resources.Routes)
+	configureResources(ctx, t, mgmtServer, nodeID, resources.Listeners, resources.Routes, nil, nil)
 
 	// Verify that that route configuration resource is requested.
 	waitForResourceNames(ctx, t, routeCfgCh, []string{resources.Routes[0].Name})

internal/xds/resolver/xds_resolver.go

@@ -150,7 +150,21 @@ func (b *xdsResolverBuilder) Build(target resolver.Target, cc resolver.ClientCon
 	}
 	r.logger = prefixLogger(r)
 	r.logger.Infof("Creating resolver for target: %+v", target)
+
+	dmSet := make(chan struct{})
+	// Schedule a callback that blocks until r.dm is set i.e xdsdepmgr.New()
+	// returns. This acts as a gatekeeper: even if dependency manager sends the
+	// updates before the xdsdepmgr.New() has a chance to return, they will be
+	// queued behind this blocker and processed only after initialization is
+	// complete.
+	r.serializer.TrySchedule(func(ctx context.Context) {
+		select {
+		case <-dmSet:
+		case <-ctx.Done():
+		}
+	})
 	r.dm = xdsdepmgr.New(r.ldsResourceName, opts.Authority, r.xdsClient, r)
+	close(dmSet)
 	return r, nil
 }
 
@@ -329,6 +343,8 @@ func (r *xdsResolver) sendNewServiceConfig(cs stoppableConfigSelector) bool {
 	state := iresolver.SetConfigSelector(resolver.State{
 		ServiceConfig: r.cc.ParseServiceConfig(string(sc)),
 	}, cs)
+	state = xdsresource.SetXDSConfig(state, r.xdsConfig)
+	state = xdsdepmgr.SetXDSClusterSubscriber(state, r.dm)
 	if err := r.cc.UpdateState(xdsclient.SetClient(state, r.xdsClient)); err != nil {
 		if r.logger.V(2) {
 			r.logger.Infof("Channel rejected new state: %+v with error: %v", state, err)

internal/xds/resolver/xds_resolver_test.go

@@ -232,7 +232,7 @@ func (s) TestResolverWatchCallbackAfterClose(t *testing.T) {
 	routes := []*v3routepb.RouteConfiguration{e2e.DefaultRouteConfig(defaultTestRouteConfigName, defaultTestServiceName, defaultTestClusterName)}
 	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
 	defer cancel()
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, nil, nil)
 
 	// Wait for a discovery request for a route configuration resource.
 	stateCh, _, r := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, contents)
@@ -300,7 +300,7 @@ func (s) TestNoMatchingVirtualHost(t *testing.T) {
 	listener := e2e.DefaultClientListener(defaultTestServiceName, defaultTestRouteConfigName)
 	route := e2e.DefaultRouteConfig(defaultTestRouteConfigName, defaultTestServiceName, defaultTestClusterName)
 	route.VirtualHosts = nil
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{listener}, []*v3routepb.RouteConfiguration{route})
+	configureResources(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{listener}, []*v3routepb.RouteConfiguration{route}, nil, nil)
 
 	// Build the resolver inline (duplicating buildResolverForTarget internals)
 	// to avoid issues with blocked channel writes when NACKs occur.
@@ -369,7 +369,7 @@ func (s) TestResolverBadServiceUpdate_NACKedWithoutCache(t *testing.T) {
 			}},
 		}},
 	}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{lis}, nil)
+	configureResources(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{lis}, nil, nil, nil)
 
 	// Build the resolver inline (duplicating buildResolverForTarget internals)
 	// to avoid issues with blocked channel writes when NACKs occur.
@@ -462,7 +462,7 @@ func (s) TestResolverBadServiceUpdate_NACKedWithCache(t *testing.T) {
 
 	// Since the resource is cached, it should be received as an ambient error
 	// and so the RPCs should continue passing.
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{lis}, nil)
+	configureResources(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{lis}, nil, nil, nil)
 
 	// "Make an RPC" by invoking the config selector which should succeed by
 	// continuing to use the previously cached resource.
@@ -552,7 +552,7 @@ func (s) TestResolverGoodServiceUpdate(t *testing.T) {
 			// route configuration resource, as specified by the test case.
 			listeners := []*v3listenerpb.Listener{e2e.DefaultClientListener(defaultTestServiceName, defaultTestRouteConfigName)}
 			routes := []*v3routepb.RouteConfiguration{tt.routeConfig}
-			configureAllResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes, tt.clusterConfig, tt.endpointConfig)
+			configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, tt.clusterConfig, tt.endpointConfig)
 
 			stateCh, _, _ := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, bc)
 
@@ -621,7 +621,7 @@ func (s) TestResolverRequestHash(t *testing.T) {
 	}}
 	cluster := []*v3clusterpb.Cluster{e2e.DefaultCluster(defaultTestClusterName, defaultTestEndpointName, e2e.SecurityLevelNone)}
 	endpoints := []*v3endpointpb.ClusterLoadAssignment{e2e.DefaultEndpoint(defaultTestEndpointName, defaultTestHostname, defaultTestPort)}
-	configureAllResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes, cluster, endpoints)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, cluster, endpoints)
 
 	// Build the resolver and read the config selector out of it.
 	stateCh, _, _ := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, bc)
@@ -908,7 +908,7 @@ func (s) TestResolverMaxStreamDuration(t *testing.T) {
 		e2e.DefaultEndpoint("endpoint_B", defaultTestHostname, defaultTestPort),
 		e2e.DefaultEndpoint("endpoint_C", defaultTestHostname, defaultTestPort),
 	}
-	configureAllResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes, cluster, endpoints)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, cluster, endpoints)
 
 	// Read the update pushed by the resolver to the ClientConn.
 	cs := verifyUpdateFromResolver(ctx, t, stateCh, "")
@@ -1084,7 +1084,7 @@ func (s) TestResolverMultipleLDSUpdates(t *testing.T) {
 	// Configure the management server with a listener resource, but no route
 	// configuration resource.
 	listeners := []*v3listenerpb.Listener{e2e.DefaultClientListener(defaultTestServiceName, defaultTestRouteConfigName)}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, nil)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, nil, nil, nil)
 
 	stateCh, _, _ := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, bc)
 
@@ -1118,7 +1118,7 @@ func (s) TestResolverMultipleLDSUpdates(t *testing.T) {
 			}},
 		}},
 	}}
-	configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, nil)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, nil, nil, nil)
 
 	// Ensure that there is no update from the resolver.
 	verifyNoUpdateFromResolver(ctx, t, stateCh)
@@ -1157,7 +1157,7 @@ func (s) TestResolverWRR(t *testing.T) {
 		e2e.DefaultEndpoint("endpoint_A", defaultTestHostname, defaultTestPort),
 		e2e.DefaultEndpoint("endpoint_B", defaultTestHostname, defaultTestPort),
 	}
-	configureAllResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, listeners, routes, clusters, endpoints)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, clusters, endpoints)
 
 	// Read the update pushed by the resolver to the ClientConn.
 	cs := verifyUpdateFromResolver(ctx, t, stateCh, "")
@@ -1251,7 +1251,7 @@ func (s) TestConfigSelector_FailureCases(t *testing.T) {
 
 			// Update the management server with a listener resource that
 			// contains inline route configuration.
-			configureResourcesOnManagementServer(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{test.listener}, nil)
+			configureResources(ctx, t, mgmtServer, nodeID, []*v3listenerpb.Listener{test.listener}, nil, nil, nil)
 
 			// Ensure that the resolver pushes a state update to the channel.
 			cs := verifyUpdateFromResolver(ctx, t, stateCh, "")
@@ -1418,3 +1418,103 @@ func (s) TestResolver_AutoHostRewrite(t *testing.T) {
 		})
 	}
 }
+
+// TestResolverKeepWatchOpen_ActiveRPCs tests that the dependency manager keeps
+// a cluster watch open when there are active RPCs using that cluster, even if
+// the cluster is no longer referenced by the current route configuration.
+func (s) TestResolverKeepWatchOpen_ActiveRPCs(t *testing.T) {
+	t.Skip("Will be enabled when all the watchers have shifted to dependency manager")
+
+	clusterA := "cluster-A"
+	clusterB := "cluster-B"
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+	cdsResourceRequestedCh := make(chan []string, 2)
+	mgmtServer := e2e.StartManagementServer(t, e2e.ManagementServerOptions{
+		OnStreamRequest: func(_ int64, req *v3discoverypb.DiscoveryRequest) error {
+			if req.GetTypeUrl() != version.V3ClusterURL {
+				return nil
+			}
+			if len(req.GetResourceNames()) > 0 {
+				select {
+				case cdsResourceRequestedCh <- req.GetResourceNames():
+				case <-ctx.Done():
+				}
+			}
+			return nil
+		},
+		AllowResourceSubset: true,
+	})
+
+	nodeID := uuid.New().String()
+	bc := e2e.DefaultBootstrapContents(t, nodeID, mgmtServer.Address)
+
+	// Configure initial resources: Route -> ClusterA.
+	listeners := []*v3listenerpb.Listener{e2e.DefaultClientListener(defaultTestServiceName, defaultTestRouteConfigName)}
+	routes := []*v3routepb.RouteConfiguration{e2e.DefaultRouteConfig(defaultTestRouteConfigName, defaultTestServiceName, clusterA)}
+	clusters := []*v3clusterpb.Cluster{
+		e2e.DefaultCluster(clusterA, "endpoint-A", e2e.SecurityLevelNone),
+		e2e.DefaultCluster(clusterB, "endpoint-B", e2e.SecurityLevelNone),
+	}
+	endpoints := []*v3endpointpb.ClusterLoadAssignment{
+		e2e.DefaultEndpoint("endpoint-A", "localhost", []uint32{8080}),
+		e2e.DefaultEndpoint("endpoint-B", "localhost", []uint32{8081}),
+	}
+
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, clusters, endpoints)
+
+	stateCh, _, _ := buildResolverForTarget(t, resolver.Target{URL: *testutils.MustParseURL("xds:///" + defaultTestServiceName)}, bc)
+
+	cs := verifyUpdateFromResolver(ctx, t, stateCh, wantServiceConfig(clusterA))
+
+	// Start RPC (Ref Counts ClusterA).
+	res, err := cs.SelectConfig(iresolver.RPCInfo{Context: ctx, Method: "/service/method"})
+	if err != nil {
+		t.Fatalf("cs.SelectConfig(): %v", err)
+	}
+
+	// Switch Configuration to ClusterB.
+	routes[0] = e2e.DefaultRouteConfig(defaultTestRouteConfigName, defaultTestServiceName, clusterB)
+	configureResources(ctx, t, mgmtServer, nodeID, listeners, routes, clusters, endpoints)
+
+	// Resolver should request BOTH A (due to active RPC) and B (due to new
+	// config).
+	wantNames := []string{clusterA, clusterB}
+	waitForResourceNames(ctx, t, cdsResourceRequestedCh, wantNames)
+
+	// Verify Service Config has both clusters.
+	const wantServiceRaw = `{
+      "loadBalancingConfig": [{
+        "xds_cluster_manager_experimental": {
+          "children": {
+            "cluster:cluster-A": {
+              "childPolicy": [{"cds_experimental": {"cluster": "cluster-A"}}]
+            },
+            "cluster:cluster-B": {
+              "childPolicy": [{"cds_experimental": {"cluster": "cluster-B"}}]
+            }
+          }
+        }
+      }]
+    }`
+	verifyUpdateFromResolver(ctx, t, stateCh, wantServiceRaw)
+
+	// Finish RPC (Drops Ref to ClusterA).
+	res.OnCommitted()
+
+	// ONLY cluster B should be requested now that there are no references to
+	// cluster A.
+	wantNames = []string{clusterB}
+	waitForResourceNames(ctx, t, cdsResourceRequestedCh, wantNames)
+
+	// ServiceConfig update should also contain only cluster B.
+	verifyUpdateFromResolver(ctx, t, stateCh, wantServiceConfig(clusterB))
+
+	// Verify that RPCs pass again.
+	res, err = cs.SelectConfig(iresolver.RPCInfo{Context: ctx, Method: "/service/method"})
+	if err != nil {
+		t.Fatalf("cs.SelectConfig(): %v", err)
+	}
+	res.OnCommitted()
+}