fix ut

Signed-off-by: zbb88888 <jmdxjsjgcxy@gmail.com>

Author: zbb88888

pkg/controller/vpc_nat_gateway.go

@@ -852,7 +852,11 @@ func (c *Controller) genNatGwStatefulSet(gw *kubeovnv1.VpcNatGateway, oldSts *v1
 		annotations = maps.Clone(oldSts.Annotations)
 	}
 
-	externalNadNamespace, externalNadName := c.getExternalSubnetNad(gw)
+	externalNadNamespace, externalNadName, err := c.getExternalSubnetNad(gw)
+	if err != nil {
+		klog.Errorf("failed to get gw external subnet nad: %v", err)
+		return nil, err
+	}
 
 	eth0SubnetProvider, err := c.GetSubnetProvider(gw.Spec.Subnet)
 	if err != nil {

pkg/controller/vpc_nat_gateway_test.go

@@ -185,6 +185,23 @@ func TestGetExternalSubnetNad(t *testing.T) {
 			expectedName:      "ovn-vpc-external-network",
 			expectError:       false,
 		},
+		{
+			name: "empty provider (fallback to subnet name)",
+			gw: &kubeovnv1.VpcNatGateway{
+				ObjectMeta: metav1.ObjectMeta{Name: "test-gw"},
+				Spec:       kubeovnv1.VpcNatGatewaySpec{ExternalSubnets: []string{"my-external-subnet"}},
+			},
+			subnets: []*kubeovnv1.Subnet{
+				{
+					ObjectMeta: metav1.ObjectMeta{Name: "my-external-subnet"},
+					Spec:       kubeovnv1.SubnetSpec{Provider: ""},
+				},
+			},
+			podNamespace:      "kube-system",
+			expectedNamespace: "kube-system",
+			expectedName:      "my-external-subnet",
+			expectError:       false,
+		},
 		{
 			name: "empty ExternalSubnets (use default)",
 			gw: &kubeovnv1.VpcNatGateway{