grpc-js-xds: xds_cluster_manager: pass along updates to existing children

packages/grpc-js-xds/src/load-balancer-xds-cluster-manager.ts

@@ -227,13 +227,14 @@ class XdsClusterManager implements LoadBalancer {
       this.children.get(name)!.destroy();
       this.children.delete(name);
     }
-    // Add new children that were not in the previous config
+    // Update all children, and add any new ones
     for (const [name, childConfig] of configChildren.entries()) {
-      if (!this.children.has(name)) {
-        const newChild = new this.XdsClusterManagerChildImpl(this, name);
-        newChild.updateAddressList(endpointList, childConfig, attributes);
-        this.children.set(name, newChild);
+      let child = this.children.get(name);
+      if (!child) {
+        child = new this.XdsClusterManagerChildImpl(this, name);
+        this.children.set(name, child);
       }
+      child.updateAddressList(endpointList, childConfig, attributes);
     }
     this.updatesPaused = false;
     this.updateState();

packages/grpc-js-xds/test/framework.ts

@@ -386,7 +386,7 @@ export class FakeServerRoute {
   private listener: Listener;
   private routeConfiguration: RouteConfiguration;
   constructor(port: number, routeName: string, baseListener?: Listener | undefined, baseRouteConfiguration?: RouteConfiguration) {
-    this.listener = baseListener ?? DEFAULT_BASE_SERVER_LISTENER;
+    this.listener = baseListener ?? {...DEFAULT_BASE_SERVER_LISTENER};
     this.listener.name = `[::1]:${port}`;
     this.listener.address = {
       socket_address: {
@@ -414,7 +414,7 @@ export class FakeServerRoute {
       filterChain.filters = filterList;
     }
 
-    this.routeConfiguration = baseRouteConfiguration ?? DEFAULT_BASE_SERVER_ROUTE_CONFIG;
+    this.routeConfiguration = baseRouteConfiguration ?? {...DEFAULT_BASE_SERVER_ROUTE_CONFIG};
     this.routeConfiguration.name = routeName;
   }
 

packages/grpc-js-xds/test/test-core.ts

@@ -134,5 +134,36 @@ describe('core xDS functionality', () => {
         });
       }, reason => done(reason));
     }, reason => done(reason));
+  });
+  it('should handle cluster config changes', async () => {
+    const [backend1, backend2] = await createBackends(2);
+    const serverRoute1 = new FakeServerRoute(backend1.getPort(), 'serverRoute');
+    const serverRoute2 = new FakeServerRoute(backend2.getPort(), 'serverRoute2');
+    xdsServer.setRdsResource(serverRoute1.getRouteConfiguration());
+    xdsServer.setLdsResource(serverRoute1.getListener());
+    xdsServer.setRdsResource(serverRoute2.getRouteConfiguration());
+    xdsServer.setLdsResource(serverRoute2.getListener());
+    xdsServer.addResponseListener((typeUrl, responseState) => {
+      if (responseState.state === 'NACKED') {
+        client?.stopCalls();
+        assert.fail(`Client NACKED ${typeUrl} resource with message ${responseState.errorMessage}`);
+      }
+    });
+    const cluster1 = new FakeEdsCluster('cluster1', 'endpoint1', [{backends: [backend1], locality:{region: 'region1'}}]);
+    const routeGroup1 = new FakeRouteGroup('listener1', 'route1', [{cluster: cluster1}]);
+    await routeGroup1.startAllBackends(xdsServer);
+    xdsServer.setEdsResource(cluster1.getEndpointConfig());
+    xdsServer.setCdsResource(cluster1.getClusterConfig());
+    xdsServer.setRdsResource(routeGroup1.getRouteConfiguration());
+    xdsServer.setLdsResource(routeGroup1.getListener());
+    client = XdsTestClient.createFromServer('listener1', xdsServer);
+    client.startCalls(100);
+    await cluster1.waitForAllBackendsToReceiveTraffic();
+    const cluster2 = new FakeEdsCluster('cluster1', 'endpoint1', [{backends: [backend2], locality:{region: 'region2'}}]);
+    await cluster2.startAllBackends(xdsServer);
+    xdsServer.setEdsResource(cluster2.getEndpointConfig());
+    await cluster2.waitForAllBackendsToReceiveTraffic();
+    client.stopCalls();
+
   })
 });