fix: avoid OVN northd "No path for static route" warning on startup

During controller startup, default gateway static routes (0.0.0.0/0 and
::/0) were added to the OVN logical router before the join subnet's
Logical Router Port was created, causing OVN northd to warn about
unreachable next hops.

This fix ensures routes are only added after the join subnet's OVN
Logical Switch and LRP exist:

1. Remove addNodeGatewayStaticRoute() call from syncNodeRoutes() which
   runs during init phase before any OVN logical switches are created.

2. Add LogicalSwitchExists check in handleAddOrUpdateVpc() to requeue
   the VPC if the join subnet's logical switch is not yet ready, avoiding
   the race between VPC worker and Subnet worker.

3. Remove redundant addNodeGatewayStaticRoute() call from handleAddNode()
   since handleAddOrUpdateVpc() already manages default route reconciliation
   as part of VPC route diffing. Also remove the now-unused function.

Signed-off-by: Mengxin Liu <liumengxinfly@gmail.com>
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Mengxin Liu <liumengxinfly@gmail.com>

Author: oilbeater

pkg/controller/init.go

@@ -904,10 +904,6 @@ func (c *Controller) syncNodeRoutes() error {
 		return err
 	}
 
-	if err := c.addNodeGatewayStaticRoute(); err != nil {
-		klog.Errorf("failed to add static route for node gateway")
-		return err
-	}
 	return nil
 }
 

pkg/controller/node.go

@@ -241,11 +241,6 @@ func (c *Controller) handleAddNode(key string) error {
 		}
 	}
 
-	if err := c.addNodeGatewayStaticRoute(); err != nil {
-		klog.Errorf("failed to add static route for node gw: %v", err)
-		return err
-	}
-
 	patch := util.KVPatch{
 		util.IPAddressAnnotation:     ipStr,
 		util.MacAddressAnnotation:    mac,
@@ -918,42 +913,6 @@ func (c *Controller) UpdateChassisTag(node *v1.Node) error {
 	return nil
 }
 
-func (c *Controller) addNodeGatewayStaticRoute() error {
-	// If user not manage static route for default vpc, just add route about ovn-default to join
-	if vpc, err := c.vpcsLister.Get(c.config.ClusterRouter); err != nil || vpc.Spec.StaticRoutes != nil {
-		existRoute, err := c.OVNNbClient.ListLogicalRouterStaticRoutes(c.config.ClusterRouter, nil, nil, "", nil)
-		if err != nil {
-			klog.Errorf("failed to get vpc %s static route list, %v", c.config.ClusterRouter, err)
-		}
-		if len(existRoute) != 0 {
-			klog.Infof("skip add static route for node gw")
-			return nil
-		}
-	}
-	dstCidr := "0.0.0.0/0,::/0"
-	for cidrBlock := range strings.SplitSeq(dstCidr, ",") {
-		for nextHop := range strings.SplitSeq(c.config.NodeSwitchGateway, ",") {
-			if util.CheckProtocol(cidrBlock) != util.CheckProtocol(nextHop) {
-				continue
-			}
-
-			if err := c.addStaticRouteToVpc(
-				c.config.ClusterRouter,
-				&kubeovnv1.StaticRoute{
-					Policy:     kubeovnv1.PolicyDst,
-					CIDR:       cidrBlock,
-					NextHopIP:  nextHop,
-					RouteTable: util.MainRouteTable,
-				},
-			); err != nil {
-				klog.Errorf("failed to add static route for node gw: %v", err)
-				return err
-			}
-		}
-	}
-	return nil
-}
-
 func (c *Controller) getPolicyRouteParams(cidr string, priority int) (*strset.Set, map[string]string, error) {
 	ipSuffix := "ip4"
 	if util.CheckProtocol(cidr) == kubeovnv1.ProtocolIPv6 {

pkg/controller/vpc.go

@@ -383,6 +383,17 @@ func (c *Controller) handleAddOrUpdateVpc(key string) error {
 			c.addOrUpdateVpcQueue.Add(vpc.Name)
 			return nil
 		}
+
+		// Ensure the join subnet's OVN Logical Switch (and its LRP) has been created
+		// before adding default routes. Otherwise, OVN northd will warn about unreachable next hops.
+		if exist, err := c.OVNNbClient.LogicalSwitchExists(c.config.NodeSwitch); err != nil {
+			klog.Errorf("failed to check logical switch %s existence: %v", c.config.NodeSwitch, err)
+			return err
+		} else if !exist {
+			klog.Infof("logical switch %s not ready, requeue vpc %s", c.config.NodeSwitch, vpc.Name)
+			c.addOrUpdateVpcQueue.Add(vpc.Name)
+			return nil
+		}
 		gatewayV4, gatewayV6 := util.SplitStringIP(joinSubnet.Spec.Gateway)
 		if gatewayV4 != "" {
 			for table := range staticRouteMapping {