fix: check northd endpoint by pod IP protocol in ovn leader checker (#6523)

Instead of skipping IPv6 addresses, now the checkNorthdEpAlive function
determines the expected AddressType based on the pod's own IP protocol
(IPv4 or IPv6) and only checks endpoint slices matching that protocol.

This ensures proper endpoint availability checking for both IPv4 and
IPv6 deployments.

Signed-off-by: clyi <clyi@alauda.io>

Author: changluyi

pkg/ovn_leader_checker/ovn.go

@@ -282,26 +282,34 @@ func checkNorthdEpAvailable(ip string) bool {
 	return true
 }
 
-func checkNorthdEpAlive(cfg *Configuration, namespace, service string) bool {
+func checkNorthdEpAlive(cfg *Configuration, namespace, service string, expectedAddrType discoveryv1.AddressType) bool {
 	epsList, err := cfg.KubeClient.DiscoveryV1().EndpointSlices(namespace).List(context.Background(), metav1.ListOptions{LabelSelector: labelSelector})
 	if err != nil {
 		klog.Errorf("failed to list endpoint slices for service %s/%s: %v", namespace, service, err)
 		return false
 	}
 
 	for _, eps := range epsList.Items {
+		// Only check endpoint slices matching the pod IP protocol
+		if eps.AddressType != expectedAddrType {
+			continue
+		}
+
 		for _, ep := range eps.Endpoints {
 			if (ep.Conditions.Ready != nil && !*ep.Conditions.Ready) || len(ep.Addresses) == 0 {
 				continue
 			}
 
-			// Found an address, check its availability. We only need one.
-			klog.V(5).Infof("found address %s in endpoint slice %s/%s for service %s, checking availability", ep.Addresses[0], eps.Namespace, eps.Name, service)
-			return checkNorthdEpAvailable(ep.Addresses[0])
+			for _, address := range ep.Addresses {
+				klog.V(5).Infof("found address %s in endpoint slice %s/%s for service %s, checking availability", address, eps.Namespace, eps.Name, service)
+				if checkNorthdEpAvailable(address) {
+					return true
+				}
+			}
 		}
 	}
 
-	klog.V(5).Infof("no address found in any endpoint slices for service %s/%s", namespace, service)
+	klog.V(5).Infof("no address found in any endpoint slices for service %s/%s with AddressType %s", namespace, service, expectedAddrType)
 	return false
 }
 
@@ -422,6 +430,15 @@ func doOvnLeaderCheck(cfg *Configuration, podName, podNamespace string) {
 		util.LogFatalAndExit(nil, "preValidChkCfg: invalid cfg")
 	}
 
+	// Determine the expected AddressType based on pod IP protocol
+	podIP := os.Getenv(util.EnvPodIP)
+	var expectedAddrType discoveryv1.AddressType
+	if util.CheckProtocol(podIP) == kubeovnv1.ProtocolIPv6 {
+		expectedAddrType = discoveryv1.AddressTypeIPv6
+	} else {
+		expectedAddrType = discoveryv1.AddressTypeIPv4
+	}
+
 	if !cfg.IsICDBServer && !checkOvnIsAlive() {
 		klog.Errorf("ovn is not alive")
 		return
@@ -441,7 +458,7 @@ func doOvnLeaderCheck(cfg *Configuration, podName, podNamespace string) {
 			return
 		}
 		if sbLeader && checkNorthdSvcExist(cfg, podNamespace, "ovn-northd") {
-			if !checkNorthdEpAlive(cfg, podNamespace, "ovn-northd") {
+			if !checkNorthdEpAlive(cfg, podNamespace, "ovn-northd", expectedAddrType) {
 				klog.Warning("no available northd leader, try to release the lock")
 				stealLock()
 			}