Adjust OVN TransitSwitchIP initialization

We've observed E2E failures on route agent restart that was caused by
the addition of the TransitSwitchIP refactoring. On code inspection,
there's a potential timing issue related to initialization of the
TransitSwitchIP. The Init method is called by
NonGatewayRouteHandler.Init however the NewNonGatewayRouteController
is started before that in Handler.Init so, depending on timing,
nonGatewayRouteCreatedOrUpdated could get invoked prior to
initialization of the TransitSwitchIP, in which case it would observe
an empty IP.

To avoid this, move the TransitSwitchIP.Init call to Handler.Init prior
to starting the NewNonGatewayRouteController.

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

pkg/routeagent_driver/handlers/ovn/handler.go

@@ -51,7 +51,7 @@ type HandlerConfig struct {
 	DynClient       dynamic.Interface
 	WatcherConfig   *watcher.Config
 	NewOVSDBClient  NewOVSDBClientFn
-	TransitSwitchIP TransitSwitchIPGetter
+	TransitSwitchIP TransitSwitchIP
 }
 
 type Handler struct {
@@ -114,6 +114,11 @@ func (ovn *Handler) Init() error {
 		return errors.Wrapf(err, "error getting connection handler to connect to OvnDB")
 	}
 
+	err = ovn.TransitSwitchIP.Init(ovn.K8sClient)
+	if err != nil {
+		return errors.Wrap(err, "error initializing TransitSwitchIP")
+	}
+
 	gatewayRouteController, err := NewGatewayRouteController(*ovn.WatcherConfig, connectionHandler, ovn.Namespace)
 	if err != nil {
 		return err

pkg/routeagent_driver/handlers/ovn/handler_test.go

@@ -102,7 +102,6 @@ var _ = Describe("Handler", func() {
 		}))
 
 		Expect(ovsdbClient.Connected()).To(BeTrue())
-		Expect(transitSwitchIP.Init(t.k8sClient)).To(Succeed())
 	})
 
 	When("a remote Endpoint is created, updated, and deleted", func() {

pkg/routeagent_driver/handlers/ovn/non_gateway_route_handler.go

@@ -31,29 +31,26 @@ import (
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/client-go/kubernetes"
 )
 
 type NonGatewayRouteHandler struct {
 	event.HandlerBase
 	event.NodeHandlerBase
 	smClient        submarinerClientset.Interface
-	k8sClient       kubernetes.Interface
 	transitSwitchIP TransitSwitchIP
 }
 
-func NewNonGatewayRouteHandler(smClient submarinerClientset.Interface, k8sClient kubernetes.Interface, transitSwitchIP TransitSwitchIP,
+func NewNonGatewayRouteHandler(smClient submarinerClientset.Interface, transitSwitchIP TransitSwitchIP,
 ) *NonGatewayRouteHandler {
 	return &NonGatewayRouteHandler{
 		smClient:        smClient,
-		k8sClient:       k8sClient,
 		transitSwitchIP: transitSwitchIP,
 	}
 }
 
 func (h *NonGatewayRouteHandler) Init() error {
 	logger.Info("Starting NonGatewayRouteHandler")
-	return errors.Wrap(h.transitSwitchIP.Init(h.k8sClient), "error initializing TransitSwitchIP")
+	return nil
 }
 
 func (h *NonGatewayRouteHandler) GetName() string {

pkg/routeagent_driver/handlers/ovn/non_gateway_route_handler_test.go

@@ -38,7 +38,9 @@ var _ = Describe("NonGatewayRouteHandler", func() {
 	t := newTestDriver()
 
 	JustBeforeEach(func() {
-		t.Start(ovn.NewNonGatewayRouteHandler(t.submClient, t.k8sClient, ovn.NewTransitSwitchIP()))
+		tsIP := ovn.NewTransitSwitchIP()
+		t.Start(ovn.NewNonGatewayRouteHandler(t.submClient, tsIP))
+		Expect(tsIP.Init(t.k8sClient)).To(Succeed())
 	})
 
 	awaitNonGatewayRoute := func(ep *submarinerv1.Endpoint) {

pkg/routeagent_driver/main.go

@@ -156,7 +156,7 @@ func main() {
 			TransitSwitchIP: transitSwitchIP,
 		}),
 		ovn.NewGatewayRouteHandler(smClientset),
-		ovn.NewNonGatewayRouteHandler(smClientset, k8sClientSet, transitSwitchIP),
+		ovn.NewNonGatewayRouteHandler(smClientset, transitSwitchIP),
 		cabledriver.NewXRFMCleanupHandler(),
 		cabledriver.NewVXLANCleanup(),
 		mtu.NewMTUHandler(env.ClusterCidr, len(env.GlobalCidr) != 0, getTCPMssValue(localNode)),