Enhance service gateway existence check and configuration validation

Author: georgeedward2000

pkg/provider/azure_servicegateway.go

@@ -13,14 +13,23 @@ import (
 )
 
 func (az *Cloud) existsServiceGateway(ctx context.Context, serviceGatewayName string) (bool, error) {
-	_, err := az.GetServiceGateway(ctx, serviceGatewayName)
+	sgw, err := az.GetServiceGateway(ctx, serviceGatewayName)
 	if err != nil {
 		if strings.Contains(err.Error(), consts.ResourceNotFoundMessageCode) {
 			return false, nil
 		}
 		klog.Infof("ExistsServiceGateway: error checking existence of Service Gateway %s in resource group %s: %v", serviceGatewayName, az.ResourceGroup, err)
 		return false, err
 	}
+
+	if sgw == nil || sgw.Properties == nil || sgw.Properties.RouteTargetAddress == nil ||
+		sgw.Properties.RouteTargetAddress.PrivateIPAllocationMethod == nil ||
+		*sgw.Properties.RouteTargetAddress.PrivateIPAllocationMethod != armnetwork.IPAllocationMethodDynamic ||
+		sgw.Properties.RouteTargetAddress.Subnet == nil {
+		klog.Infof("ExistsServiceGateway: Service Gateway %s in resource group %s is not properly configured", serviceGatewayName, az.ResourceGroup)
+		return false, nil
+	}
+
 	return true, nil
 }
 
@@ -39,6 +48,18 @@ func (az *Cloud) createServiceGateway(ctx context.Context, serviceGatewayName st
 				az.ResourceGroup,
 				az.VnetName,
 			))},
+			RouteTargetAddress: &armnetwork.RouteTargetAddressPropertiesFormat{
+				PrivateIPAllocationMethod: to.Ptr(armnetwork.IPAllocationMethodDynamic),
+				Subnet: &armnetwork.Subnet{
+					ID: to.Ptr(fmt.Sprintf(
+						"/subscriptions/%s/resourceGroups/%s/providers/Microsoft.Network/virtualNetworks/%s/subnets/%s",
+						az.SubscriptionID,
+						az.ResourceGroup,
+						az.VnetName,
+						az.SubnetName,
+					)),
+				},
+			},
 		},
 	}
 	// logObject(serviceGateway)