From 240ef41335d28aa6607e686e4483b5dc6efd7588 Mon Sep 17 00:00:00 2001
From: rambohe <rambohe.ch@gmail.com>
Date: Thu, 4 Nov 2021 02:35:42 +0800
Subject: [PATCH] enhancement: add openyurt.io/skip-discard annotation verify
 for discardcloudservice filter (#542)

---
 pkg/yurthub/filter/constant.go                    | 11 ++++++++---
 pkg/yurthub/filter/discardcloudservice/handler.go | 12 ++++++++----
 pkg/yurthub/filter/servicetopology/handler.go     |  6 ------
 3 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/pkg/yurthub/filter/constant.go b/pkg/yurthub/filter/constant.go
index 74daf6c0fce..29cb756d1ac 100644
--- a/pkg/yurthub/filter/constant.go
+++ b/pkg/yurthub/filter/constant.go
@@ -17,17 +17,22 @@ limitations under the License.
 package filter
 
 const (
-	// masterservice filter is used to mutate the ClusterIP and https port of default/kubernetes service
+	// MasterServiceFilterName filter is used to mutate the ClusterIP and https port of default/kubernetes service
 	// in order to pods on edge nodes can access kube-apiserver directly by inClusterConfig.
 	MasterServiceFilterName = "masterservice"
 
-	// servicetopology filter is used to reassemble endpointslice in order to make the service traffic
+	// ServiceTopologyFilterName filter is used to reassemble endpointslice in order to make the service traffic
 	// under the topology that defined by service.Annotation["openyurt.io/topologyKeys"]
 	ServiceTopologyFilterName = "servicetopology"
 
-	// discardcloudservice filter is used to discard cloud service(like loadBalancer service)
+	// DiscardCloudServiceFilterName filter is used to discard cloud service(like loadBalancer service)
 	// on kube-proxy list/watch service request from edge nodes.
 	DiscardCloudServiceFilterName = "discardcloudservice"
+
+	// SkipDiscardServiceAnnotation is annotation used by LB service.
+	// If end users want to use specified LB service at the edge side,
+	// End users should add annotation["openyurt.io/skip-discard"]="true" for LB service.
+	SkipDiscardServiceAnnotation = "openyurt.io/skip-discard"
 )
 
 // DisabledInCloudMode contains the filters that should be disabled when yurthub is working in cloud mode.
diff --git a/pkg/yurthub/filter/discardcloudservice/handler.go b/pkg/yurthub/filter/discardcloudservice/handler.go
index f693fcd2508..bde5f025694 100644
--- a/pkg/yurthub/filter/discardcloudservice/handler.go
+++ b/pkg/yurthub/filter/discardcloudservice/handler.go
@@ -59,8 +59,10 @@ func (fh *discardCloudServiceFilterHandler) ObjectResponseFilter(b []byte) ([]by
 			nsName := fmt.Sprintf("%s/%s", serviceList.Items[i].Namespace, serviceList.Items[i].Name)
 			// remove lb service
 			if serviceList.Items[i].Spec.Type == v1.ServiceTypeLoadBalancer {
-				klog.V(2).Infof("load balancer service(%s) is discarded in ObjectResponseFilter of discardCloudServiceFilterHandler", nsName)
-				continue
+				if serviceList.Items[i].Annotations[filter.SkipDiscardServiceAnnotation] != "true" {
+					klog.V(2).Infof("load balancer service(%s) is discarded in ObjectResponseFilter of discardCloudServiceFilterHandler", nsName)
+					continue
+				}
 			}
 
 			// remove cloud clusterIP service
@@ -101,8 +103,10 @@ func (fh *discardCloudServiceFilterHandler) StreamResponseFilter(rc io.ReadClose
 			nsName := fmt.Sprintf("%s/%s", service.Namespace, service.Name)
 			// remove cloud LoadBalancer service
 			if service.Spec.Type == v1.ServiceTypeLoadBalancer {
-				klog.V(2).Infof("load balancer service(%s) is discarded in StreamResponseFilter of discardCloudServiceFilterHandler", nsName)
-				continue
+				if service.Annotations[filter.SkipDiscardServiceAnnotation] != "true" {
+					klog.V(2).Infof("load balancer service(%s) is discarded in StreamResponseFilter of discardCloudServiceFilterHandler", nsName)
+					continue
+				}
 			}
 
 			// remove cloud clusterIP service
diff --git a/pkg/yurthub/filter/servicetopology/handler.go b/pkg/yurthub/filter/servicetopology/handler.go
index 69f9c9dcae5..f50fb9681a2 100644
--- a/pkg/yurthub/filter/servicetopology/handler.go
+++ b/pkg/yurthub/filter/servicetopology/handler.go
@@ -134,12 +134,6 @@ func (fh *serviceTopologyFilterHandler) reassembleEndpointSlice(endpointSlice *d
 			return endpointSlice
 		}
 
-		// discard endpointSlice if service type is LoadBalancer
-		if svc.Spec.Type == v1.ServiceTypeLoadBalancer {
-			klog.Infof("endpointSlice(%s/%s) of load balancer service is discarded", endpointSlice.Namespace, endpointSlice.Name)
-			return nil
-		}
-
 		if serviceTopologyType, ok = svc.Annotations[AnnotationServiceTopologyKey]; !ok {
 			klog.Infof("skip reassemble endpointSlice, service %s/%s has no annotation %s", endpointSlice.Namespace, svcName, AnnotationServiceTopologyKey)
 			return endpointSlice