Fix HTTPRoute parentRefs updates

pkg/kthena-router/controller/httproute_controller.go

@@ -18,6 +18,7 @@ package controller
 
 import (
 	"fmt"
+	"reflect"
 	"sync/atomic"
 	"time"
 
@@ -187,6 +188,10 @@ func (c *HTTPRouteController) syncHandler(key string) error {
 		}
 	}
 	if gatewayPending {
+		oldRoute := c.store.GetHTTPRoute(key)
+		if oldRoute != nil && !reflect.DeepEqual(oldRoute.Spec.ParentRefs, httpRoute.Spec.ParentRefs) {
+			_ = c.store.DeleteHTTPRoute(key)
+		}
 		return fmt.Errorf("gateway not synced yet")
 	}
 	klog.V(4).Infof("Skipping HTTPRoute %s/%s: does not reference kthena-router Gateway", namespace, name)

pkg/kthena-router/controller/httproute_controller_test.go

@@ -208,3 +208,54 @@ func TestHTTPRouteController_MultipleParentRefs_FirstPending(t *testing.T) {
 	assert.NoError(t, err)
 	assert.NotNil(t, store.GetHTTPRoute(ns+"/route-multi"))
 }
+
+func TestHTTPRouteController_SyncHandler_DeletesOldRouteWhenNewGatewayPending(t *testing.T) {
+	gatewayClient := gatewayfake.NewSimpleClientset()
+	gatewayInformerFactory := gatewayinformers.NewSharedInformerFactory(gatewayClient, 0)
+	store := datastore.New()
+
+	ctx := context.Background()
+	ns := "default"
+	kind := gatewayv1.Kind("Gateway")
+
+	oldRoute := &gatewayv1.HTTPRoute{
+		ObjectMeta: metav1.ObjectMeta{Namespace: ns, Name: "route"},
+		Spec: gatewayv1.HTTPRouteSpec{
+			CommonRouteSpec: gatewayv1.CommonRouteSpec{
+				ParentRefs: []gatewayv1.ParentReference{
+					{Kind: &kind, Name: gatewayv1.ObjectName("gateway-a")},
+				},
+			},
+		},
+	}
+	assert.NoError(t, store.AddOrUpdateHTTPRoute(oldRoute))
+
+	gw := &gatewayv1.Gateway{
+		ObjectMeta: metav1.ObjectMeta{Namespace: ns, Name: "gateway-b"},
+		Spec: gatewayv1.GatewaySpec{
+			GatewayClassName: gatewayv1.ObjectName(DefaultGatewayClassName),
+		},
+	}
+	_, err := gatewayClient.GatewayV1().Gateways(ns).Create(ctx, gw, metav1.CreateOptions{})
+	assert.NoError(t, err)
+
+	httpRoute := oldRoute.DeepCopy()
+	httpRoute.Spec.ParentRefs = []gatewayv1.ParentReference{
+		{Kind: &kind, Name: gatewayv1.ObjectName("gateway-b")},
+	}
+	_, err = gatewayClient.GatewayV1().HTTPRoutes(ns).Create(ctx, httpRoute, metav1.CreateOptions{})
+	assert.NoError(t, err)
+
+	ctrl := NewHTTPRouteController(gatewayInformerFactory, store)
+	stop := make(chan struct{})
+	defer close(stop)
+	gatewayInformerFactory.Start(stop)
+
+	if !cache.WaitForCacheSync(stop, gatewayInformerFactory.Gateway().V1().HTTPRoutes().Informer().HasSynced, gatewayInformerFactory.Gateway().V1().Gateways().Informer().HasSynced) {
+		t.Fatal("cache sync timeout")
+	}
+
+	err = ctrl.syncHandler(ns + "/route")
+	assert.Error(t, err)
+	assert.Empty(t, store.GetHTTPRoutesByGateway(ns+"/gateway-a"))
+}

pkg/kthena-router/datastore/store.go

@@ -1981,9 +1981,29 @@ func (s *store) AddOrUpdateHTTPRoute(httpRoute *gatewayv1.HTTPRoute) error {
 	key := fmt.Sprintf("%s/%s", httpRoute.Namespace, httpRoute.Name)
 
 	s.httpRouteMutex.Lock()
+	oldRoute := s.httpRoutes[key]
 	s.httpRoutes[key] = httpRoute
 
 	// Update gateway routes mapping
+	if oldRoute != nil {
+		for _, parentRef := range oldRoute.Spec.ParentRefs {
+			if parentRef.Kind != nil && *parentRef.Kind == "Gateway" {
+				gatewayName := string(parentRef.Name)
+				gatewayNamespace := oldRoute.Namespace
+				if parentRef.Namespace != nil {
+					gatewayNamespace = string(*parentRef.Namespace)
+				}
+				gatewayKey := fmt.Sprintf("%s/%s", gatewayNamespace, gatewayName)
+
+				if routeSet, exists := s.gatewayRoutes[gatewayKey]; exists {
+					routeSet.Delete(key)
+					if routeSet.IsEmpty() {
+						delete(s.gatewayRoutes, gatewayKey)
+					}
+				}
+			}
+		}
+	}
 	for _, parentRef := range httpRoute.Spec.ParentRefs {
 		if parentRef.Kind != nil && *parentRef.Kind == "Gateway" {
 			gatewayName := string(parentRef.Name)

pkg/kthena-router/datastore/store_test.go

@@ -1562,6 +1562,28 @@ func newStore(inspector ...PodRuntimeInspector) *store {
 	return New(WithPodRuntimeInspector(inspector[0])).(*store)
 }
 
+func TestAddOrUpdateHTTPRoute_UpdatesGatewayRoutes(t *testing.T) {
+	kind := gatewayv1.Kind("Gateway")
+	s := newStore()
+
+	route := &gatewayv1.HTTPRoute{
+		ObjectMeta: metav1.ObjectMeta{Namespace: "default", Name: "route"},
+		Spec: gatewayv1.HTTPRouteSpec{
+			CommonRouteSpec: gatewayv1.CommonRouteSpec{
+				ParentRefs: []gatewayv1.ParentReference{{Name: "gateway-a", Kind: &kind}},
+			},
+		},
+	}
+	assert.NoError(t, s.AddOrUpdateHTTPRoute(route))
+
+	route = route.DeepCopy()
+	route.Spec.ParentRefs = []gatewayv1.ParentReference{{Name: "gateway-b", Kind: &kind}}
+	assert.NoError(t, s.AddOrUpdateHTTPRoute(route))
+
+	assert.Empty(t, s.GetHTTPRoutesByGateway("default/gateway-a"))
+	assert.Len(t, s.GetHTTPRoutesByGateway("default/gateway-b"), 1)
+}
+
 func TestAddOrUpdatePod_MetricsPreservedOnUpdate(t *testing.T) {
 	sampleCount := uint64(100)
 	sampleSum := 0.42