node subnet needs to handle this too

Author: paulgmiller

cns/restserver/helper_for_nodesubnet_test.go

@@ -79,7 +79,8 @@ func GetRestServiceObjectForNodeSubnetTest(t *testing.T, generator CNIConflistGe
 				return interfaces, nil
 			},
 		},
-		wscli: &fakes.WireserverClientFake{},
+		wscli:    &fakes.WireserverClientFake{},
+		ncSynced: make(chan struct{}),
 	}
 }
 

cns/restserver/nodesubnet.go

@@ -58,6 +58,10 @@ func (service *HTTPRestService) InitializeNodeSubnet(ctx context.Context, podInf
 
 // StartNodeSubnet starts the IP fetcher for NodeSubnet. This will cause secondary IPs to be fetched periodically.
 // After the first successful fetch, conflist will be generated to indicate CNS is ready.
-func (service *HTTPRestService) StartNodeSubnet(ctx context.Context) {
+func (service *HTTPRestService) StartNodeSubnet(ctx context.Context) error {
+	if !service.ncSyncLoop.CompareAndSwap(false, true) {
+		return errors.New("SyncHostNCVersion loop already started")
+	}
 	service.nodesubnetIPFetcher.Start(ctx)
+	return nil
 }

cns/restserver/nodesubnet_test.go

@@ -96,7 +96,9 @@ func TestNodeSubnet(t *testing.T) {
 
 	checkIPassignment(t, service, expectedIPs)
 
-	service.StartNodeSubnet(ctx)
+	if err := service.StartNodeSubnet(ctx); err != nil {
+		t.Fatalf("StartNodeSubnet returned an error: %v", err)
+	}
 
 	if service.GetNodesubnetIPFetcher() == nil {
 		t.Fatal("NodeSubnetIPFetcher is not initialized")

cns/service/main.go

@@ -1115,7 +1115,10 @@ func main() {
 		// at this point, rest service is running. We can now start serving new requests. So call StartNodeSubnet, which
 		// will fetch secondary IPs and generate conflist. Do not move this all before rest service start - this will cause
 		// CNI to start sending requests, and if the service doesn't start successfully, the requests will fail.
-		httpRemoteRestService.StartNodeSubnet(rootCtx)
+		if err := httpRemoteRestService.StartNodeSubnet(rootCtx); err != nil {
+			logger.Errorf("Failed to start NodeSubnet: %v", err)
+			return
+		}
 	}
 
 	// Wait for NC sync to complete before marking service as ready.