Change diffBackends for NEG to not compare the API versions.

pkg/backends/neg_linker.go

@@ -167,13 +167,15 @@ func diffBackends(old, new []*composite.Backend) *backendDiff {
 
 	oldMap := map[string]*composite.Backend{}
 	for _, be := range old {
-		d.old.Insert(be.Group)
-		oldMap[be.Group] = be
+		beGroup := relativeResourceNameWithDefault(be.Group)
+		d.old.Insert(beGroup)
+		oldMap[beGroup] = be
 	}
 	for _, be := range new {
-		d.new.Insert(be.Group)
+		beGroup := relativeResourceNameWithDefault(be.Group)
+		d.new.Insert(beGroup)
 
-		if oldBe, ok := oldMap[be.Group]; ok {
+		if oldBe, ok := oldMap[beGroup]; ok {
 			// Note: if you are comparing a value that has a non-zero default
 			// value (e.g. CapacityScaler is 1.0), you will need to set that
 			// value when creating a new Backend to avoid a false positive when
@@ -183,7 +185,7 @@ func diffBackends(old, new []*composite.Backend) *backendDiff {
 				changed = changed || oldBe.MaxRatePerEndpoint != be.MaxRatePerEndpoint
 				changed = changed || oldBe.CapacityScaler != be.CapacityScaler
 				if changed {
-					d.changed.Insert(be.Group)
+					d.changed.Insert(beGroup)
 				}
 			}
 		}
@@ -264,3 +266,15 @@ func getNegUrlFromSvcneg(key string, zone string, svcNegLister cache.Indexer) (s
 	}
 	return "", false
 }
+
+// relativeResourceNameWithDefault will attempt to return a RelativeResourceName
+// for the provided `selfLink`. In case of a faiure, it will return the
+// `selfLink` itself.
+func relativeResourceNameWithDefault(selfLink string) string {
+	result, err := utils.RelativeResourceName(selfLink)
+	if err != nil {
+		klog.Warning("Unable to parse resource name from provided selfLink %q", selfLink)
+		return selfLink
+	}
+	return result
+}

pkg/backends/neg_linker_test.go

@@ -291,6 +291,18 @@ func TestDiffBackends(t *testing.T) {
 			new:     []*composite.Backend{{Group: "b"}, {Group: "a"}},
 			isEqual: true,
 		},
+		{
+			name: "same but different api version",
+			old: []*composite.Backend{
+				{Group: "https://www.googleapis.com/compute/beta/projects/project-name/zones/us-central1-c/networkEndpointGroups/k8s1-neg-name-1"},
+				{Group: "https://www.googleapis.com/compute/v1/projects/project-name/zones/us-central1-c/networkEndpointGroups/k8s1-neg-name-2"},
+			},
+			new: []*composite.Backend{
+				{Group: "https://www.googleapis.com/compute/v1/projects/project-name/zones/us-central1-c/networkEndpointGroups/k8s1-neg-name-1"},
+				{Group: "https://www.googleapis.com/compute/beta/projects/project-name/zones/us-central1-c/networkEndpointGroups/k8s1-neg-name-2"},
+			},
+			isEqual: true,
+		},
 		{
 			name:  "add backend",
 			old:   []*composite.Backend{{Group: "a"}},