Merge pull request kubernetes#107296 from cezarygerard/smart-ig-ilb

GCE L4 load balancer: enable migration of Instance Group management out of K/K.

staging/src/k8s.io/legacy-cloud-providers/gce/gce_alpha.go

@@ -23,6 +23,10 @@ const (
 	// AlphaFeatureILBSubsets allows InternalLoadBalancer services to include a subset
 	// of cluster nodes as backends instead of all nodes.
 	AlphaFeatureILBSubsets = "ILBSubsets"
+
+	// AlphaFeatureSkipIGsManagement enabled L4 Regional Backend Services and
+	// disables instance group management in service controller
+	AlphaFeatureSkipIGsManagement = "SkipIGsManagement"
 )
 
 // AlphaFeatureGate contains a mapping of alpha features to whether they are enabled

staging/src/k8s.io/legacy-cloud-providers/gce/gce_instancegroup.go

@@ -50,6 +50,16 @@ func (g *Cloud) DeleteInstanceGroup(name string, zone string) error {
 	return mc.Observe(g.c.InstanceGroups().Delete(ctx, meta.ZonalKey(name, zone)))
 }
 
+// FilterInstanceGroupsByName lists all InstanceGroups in the project and
+// zone that match the name regexp.
+func (g *Cloud) FilterInstanceGroupsByNamePrefix(namePrefix, zone string) ([]*compute.InstanceGroup, error) {
+	ctx, cancel := cloud.ContextWithCallTimeout()
+	defer cancel()
+	mc := newInstanceGroupMetricContext("filter", zone)
+	v, err := g.c.InstanceGroups().List(ctx, zone, filter.Regexp("name", namePrefix+".*"))
+	return v, mc.Observe(err)
+}
+
 // ListInstanceGroups lists all InstanceGroups in the project and
 // zone.
 func (g *Cloud) ListInstanceGroups(zone string) ([]*compute.InstanceGroup, error) {

staging/src/k8s.io/legacy-cloud-providers/gce/gce_loadbalancer_internal.go

@@ -625,11 +625,21 @@ func (g *Cloud) ensureInternalInstanceGroups(name string, nodes []*v1.Node) ([]s
 	klog.V(2).Infof("ensureInternalInstanceGroups(%v): %d nodes over %d zones in region %v", name, len(nodes), len(zonedNodes), g.region)
 	var igLinks []string
 	for zone, nodes := range zonedNodes {
-		igLink, err := g.ensureInternalInstanceGroup(name, zone, nodes)
-		if err != nil {
-			return []string{}, err
+		if g.AlphaFeatureGate.Enabled(AlphaFeatureSkipIGsManagement) {
+			igs, err := g.FilterInstanceGroupsByNamePrefix(name, zone)
+			if err != nil {
+				return nil, err
+			}
+			for _, ig := range igs {
+				igLinks = append(igLinks, ig.SelfLink)
+			}
+		} else {
+			igLink, err := g.ensureInternalInstanceGroup(name, zone, nodes)
+			if err != nil {
+				return nil, err
+			}
+			igLinks = append(igLinks, igLink)
 		}
-		igLinks = append(igLinks, igLink)
 	}
 
 	return igLinks, nil
@@ -642,10 +652,13 @@ func (g *Cloud) ensureInternalInstanceGroupsDeleted(name string) error {
 		return err
 	}
 
-	klog.V(2).Infof("ensureInternalInstanceGroupsDeleted(%v): attempting delete instance group in all %d zones", name, len(zones))
-	for _, z := range zones {
-		if err := g.DeleteInstanceGroup(name, z.Name); err != nil && !isNotFoundOrInUse(err) {
-			return err
+	// Skip Instance Group deletion if IG management was moved out of k/k code
+	if !g.AlphaFeatureGate.Enabled(AlphaFeatureSkipIGsManagement) {
+		klog.V(2).Infof("ensureInternalInstanceGroupsDeleted(%v): attempting delete instance group in all %d zones", name, len(zones))
+		for _, z := range zones {
+			if err := g.DeleteInstanceGroup(name, z.Name); err != nil && !isNotFoundOrInUse(err) {
+				return err
+			}
 		}
 	}
 	return nil

staging/src/k8s.io/legacy-cloud-providers/gce/gce_loadbalancer_internal_test.go

@@ -23,6 +23,7 @@ import (
 	"context"
 	"fmt"
 	"reflect"
+	"sort"
 	"strings"
 	"testing"
 
@@ -165,12 +166,39 @@ func TestEnsureInternalInstanceGroupsLimit(t *testing.T) {
 	igName := makeInstanceGroupName(vals.ClusterID)
 	_, err = gce.ensureInternalInstanceGroups(igName, nodes)
 	require.NoError(t, err)
-
 	instances, err := gce.ListInstancesInInstanceGroup(igName, vals.ZoneName, allInstances)
 	require.NoError(t, err)
 	assert.Equal(t, maxInstancesPerInstanceGroup, len(instances))
 }
 
+func TestEnsureMultipleInstanceGroups(t *testing.T) {
+	t.Parallel()
+
+	vals := DefaultTestClusterValues()
+	gce, err := fakeGCECloud(vals)
+	require.NoError(t, err)
+	gce.AlphaFeatureGate = NewAlphaFeatureGate([]string{AlphaFeatureSkipIGsManagement})
+
+	nodes, err := createAndInsertNodes(gce, []string{"n1"}, vals.ZoneName)
+	require.NoError(t, err)
+
+	baseName := makeInstanceGroupName(vals.ClusterID)
+	clusterIGs := []string{baseName, baseName + "-1", baseName + "-2", baseName + "-3"}
+	for _, igName := range append(clusterIGs, "zz-another-ig", "k8s-ig--cluster2-id") {
+		ig := &compute.InstanceGroup{Name: igName}
+		err := gce.CreateInstanceGroup(ig, vals.ZoneName)
+		require.NoError(t, err)
+	}
+
+	igsFromCloud, err := gce.ensureInternalInstanceGroups(baseName, nodes)
+	require.NoError(t, err)
+	assert.Len(t, igsFromCloud, len(clusterIGs), "Incorrect number of Instance Groups")
+	sort.Strings(igsFromCloud)
+	for i, igName := range clusterIGs {
+		assert.True(t, strings.HasSuffix(igsFromCloud[i], igName))
+	}
+}
+
 func TestEnsureInternalLoadBalancer(t *testing.T) {
 	t.Parallel()
 
@@ -525,6 +553,29 @@ func TestEnsureInternalLoadBalancerDeleted(t *testing.T) {
 	assertInternalLbResourcesDeleted(t, gce, svc, vals, true)
 }
 
+func TestSkipInstanceGroupDeletion(t *testing.T) {
+	t.Parallel()
+
+	vals := DefaultTestClusterValues()
+	gce, err := fakeGCECloud(vals)
+	require.NoError(t, err)
+
+	svc := fakeLoadbalancerService(string(LBTypeInternal))
+	svc, err = gce.client.CoreV1().Services(svc.Namespace).Create(context.TODO(), svc, metav1.CreateOptions{})
+	require.NoError(t, err)
+	_, err = createInternalLoadBalancer(gce, svc, nil, []string{"test-node-1"}, vals.ClusterName, vals.ClusterID, vals.ZoneName)
+	assert.NoError(t, err)
+
+	gce.AlphaFeatureGate = NewAlphaFeatureGate([]string{AlphaFeatureSkipIGsManagement})
+	err = gce.ensureInternalLoadBalancerDeleted(vals.ClusterName, vals.ClusterID, svc)
+	assert.NoError(t, err)
+
+	igName := makeInstanceGroupName(vals.ClusterID)
+	ig, err := gce.GetInstanceGroup(igName, vals.ZoneName)
+	assert.NoError(t, err)
+	assert.NotNil(t, ig, "Instance group should not be deleted when flag 'NetLB_RBS' is present")
+}
+
 func TestEnsureInternalLoadBalancerDeletedTwiceDoesNotError(t *testing.T) {
 	t.Parallel()