remove getAlphaInstanceGroupsToAdd

pkg/backends/backends.go

@@ -433,12 +433,7 @@ func (b *Backends) ensureBackendService(p ServicePort, igs []*compute.InstanceGr
 // edgeHop checks the links of the given backend by executing an edge hop.
 // It fixes broken links and updates the Backend accordingly.
 func (b *Backends) edgeHop(be *BackendService, igs []*compute.InstanceGroup) error {
-	addIGs := []*compute.InstanceGroup{}
-	if be.Alpha != nil {
-		addIGs = getAlphaInstanceGroupsToAdd(be, igs)
-	} else {
-		addIGs = getInstanceGroupsToAdd(be, igs)
-	}
+	addIGs := getInstanceGroupsToAdd(be, igs)
 	if len(addIGs) == 0 {
 		return nil
 	}
@@ -598,6 +593,8 @@ func getBackendsForNEGs(negs []*computealpha.NetworkEndpointGroup) []*computealp
 }
 
 func getInstanceGroupsToAdd(be *BackendService, igs []*compute.InstanceGroup) []*compute.InstanceGroup {
+	// A GA link can be used to reference an alpha object - so we only need to
+	// check the GA InstanceGroups.
 	beName := be.Ga.Name
 	beIGs := sets.String{}
 	for _, existingBe := range be.Ga.Backends {
@@ -625,34 +622,6 @@ func getInstanceGroupsToAdd(be *BackendService, igs []*compute.InstanceGroup) []
 	return addIGs
 }
 
-func getAlphaInstanceGroupsToAdd(be *BackendService, igs []*compute.InstanceGroup) []*compute.InstanceGroup {
-	beName := be.Alpha.Name
-	beIGs := sets.String{}
-	for _, existingBe := range be.Alpha.Backends {
-		beIGs.Insert(comparableGroupPath(existingBe.Group))
-	}
-
-	expectedIGs := sets.String{}
-	for _, ig := range igs {
-		expectedIGs.Insert(comparableGroupPath(ig.SelfLink))
-	}
-
-	if beIGs.IsSuperset(expectedIGs) {
-		return nil
-	}
-	glog.V(2).Infof("Expected igs for backend service %v: %+v, current igs %+v",
-		beName, expectedIGs.List(), beIGs.List())
-
-	var addIGs []*compute.InstanceGroup
-	for _, ig := range igs {
-		if !beIGs.Has(comparableGroupPath(ig.SelfLink)) {
-			addIGs = append(addIGs, ig)
-		}
-	}
-
-	return addIGs
-}
-
 // GC garbage collects services corresponding to ports in the given list.
 func (b *Backends) GC(svcNodePorts []ServicePort) error {
 	knownPorts := sets.NewString()