Adding logic to GCE ingress controller to handle multi cluster ingresses

controllers/gce/backends/backends.go

@@ -217,7 +217,7 @@ func (b *Backends) Add(p ServicePort) error {
 	be := &compute.BackendService{}
 	defer func() { b.snapshotter.Add(portKey(p.Port), be) }()
 
-	igs, namedPort, err := b.nodePool.AddInstanceGroup(b.namer.IGName(), p.Port)
+	igs, namedPort, err := instances.CreateInstanceGroups(b.nodePool, b.namer, p.Port)
 	if err != nil {
 		return err
 	}

controllers/gce/controller/cluster_manager.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/golang/glog"
 
+	compute "google.golang.org/api/compute/v1"
 	gce "k8s.io/kubernetes/pkg/cloudprovider/providers/gce"
 
 	"k8s.io/ingress/controllers/gce/backends"
@@ -132,7 +133,7 @@ func (c *ClusterManager) Checkpoint(lbs []*loadbalancers.L7RuntimeInfo, nodeName
 	if err := c.backendPool.Sync(nodePorts); err != nil {
 		return err
 	}
-	if err := c.instancePool.Sync(nodeNames); err != nil {
+	if err := c.SyncNodesInInstanceGroups(nodeNames); err != nil {
 		return err
 	}
 	if err := c.l7Pool.Sync(lbs); err != nil {
@@ -161,6 +162,25 @@ func (c *ClusterManager) Checkpoint(lbs []*loadbalancers.L7RuntimeInfo, nodeName
 	return nil
 }
 
+func (c *ClusterManager) CreateInstanceGroups(servicePorts []backends.ServicePort) ([]*compute.InstanceGroup, error) {
+	var igs []*compute.InstanceGroup
+	var err error
+	for _, p := range servicePorts {
+		igs, _, err = instances.CreateInstanceGroups(c.instancePool, c.ClusterNamer, p.Port)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return igs, nil
+}
+
+func (c *ClusterManager) SyncNodesInInstanceGroups(nodeNames []string) error {
+	if err := c.instancePool.Sync(nodeNames); err != nil {
+		return err
+	}
+	return nil
+}
+
 // GC garbage collects unused resources.
 // - lbNames are the names of L7 loadbalancers we wish to exist. Those not in
 //   this list are removed from the cloud.

controllers/gce/controller/controller.go

@@ -149,7 +149,7 @@ func NewLoadBalancerController(kubeClient kubernetes.Interface, ctx *ControllerC
 	ctx.IngressInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
 		AddFunc: func(obj interface{}) {
 			addIng := obj.(*extensions.Ingress)
-			if !isGCEIngress(addIng) {
+			if !isGCEIngress(addIng) && !isGCEMultiClusterIngress(addIng) {
 				glog.Infof("Ignoring add for ingress %v based on annotation %v", addIng.Name, ingressClassKey)
 				return
 			}
@@ -158,7 +158,7 @@ func NewLoadBalancerController(kubeClient kubernetes.Interface, ctx *ControllerC
 		},
 		DeleteFunc: func(obj interface{}) {
 			delIng := obj.(*extensions.Ingress)
-			if !isGCEIngress(delIng) {
+			if !isGCEIngress(delIng) && !isGCEMultiClusterIngress(delIng) {
 				glog.Infof("Ignoring delete for ingress %v based on annotation %v", delIng.Name, ingressClassKey)
 				return
 			}
@@ -167,7 +167,7 @@ func NewLoadBalancerController(kubeClient kubernetes.Interface, ctx *ControllerC
 		},
 		UpdateFunc: func(old, cur interface{}) {
 			curIng := cur.(*extensions.Ingress)
-			if !isGCEIngress(curIng) {
+			if !isGCEIngress(curIng) && !isGCEMultiClusterIngress(curIng) {
 				return
 			}
 			if !reflect.DeepEqual(old, cur) {
@@ -313,6 +313,13 @@ func (lbc *LoadBalancerController) sync(key string) (err error) {
 		glog.V(3).Infof("Finished syncing %v", key)
 	}()
 
+	if ingExists {
+		ing := obj.(*extensions.Ingress)
+		if isGCEMultiClusterIngress(ing) {
+			return lbc.syncMultiClusterIngress(ing, nodeNames)
+		}
+	}
+
 	// Record any errors during sync and throw a single error at the end. This
 	// allows us to free up associated cloud resources ASAP.
 	if err := lbc.CloudClusterManager.Checkpoint(lbs, nodeNames, nodePorts); err != nil {
@@ -349,6 +356,39 @@ func (lbc *LoadBalancerController) sync(key string) (err error) {
 	return syncError
 }
 
+func (lbc *LoadBalancerController) syncMultiClusterIngress(ing *extensions.Ingress, nodeNames []string) error {
+	// For multi cluster ingress, we only need to manage the instance groups and named ports on those instance groups.
+
+	// Ensure that all the required instance groups exist with the required node ports.
+	nodePorts := lbc.tr.ingressToNodePorts(ing)
+	// Add the default backend node port.
+	nodePorts = append(nodePorts, lbc.CloudClusterManager.defaultBackendNodePort)
+	igs, err := lbc.CloudClusterManager.CreateInstanceGroups(nodePorts)
+	if err != nil {
+		return err
+	}
+
+	// Ensure that instance groups have the right nodes.
+	// This is also done whenever a node is added or removed from the cluster.
+	// We need it here as well since instance group is not created until first ingress is observed.
+	if err := lbc.CloudClusterManager.SyncNodesInInstanceGroups(nodeNames); err != nil {
+		return err
+	}
+
+	// Add instance group names as annotation on the ingress.
+	if ing.Annotations == nil {
+		ing.Annotations = map[string]string{}
+	}
+	err = setInstanceGroupsAnnotation(ing.Annotations, igs)
+	if err != nil {
+		return err
+	}
+	if err := lbc.updateAnnotations(ing.Name, ing.Namespace, ing.Annotations); err != nil {
+		return err
+	}
+	return nil
+}
+
 // updateIngressStatus updates the IP and annotations of a loadbalancer.
 // The annotations are parsed by kubectl describe.
 func (lbc *LoadBalancerController) updateIngressStatus(l7 *loadbalancers.L7, ing extensions.Ingress) error {
@@ -379,14 +419,23 @@ func (lbc *LoadBalancerController) updateIngressStatus(l7 *loadbalancers.L7, ing
 			lbc.recorder.Eventf(currIng, apiv1.EventTypeNormal, "CREATE", "ip: %v", ip)
 		}
 	}
+	annotations := loadbalancers.GetLBAnnotations(l7, currIng.Annotations, lbc.CloudClusterManager.backendPool)
+	if err := lbc.updateAnnotations(ing.Name, ing.Namespace, annotations); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (lbc *LoadBalancerController) updateAnnotations(name, namespace string, annotations map[string]string) error {
 	// Update annotations through /update endpoint
-	currIng, err = ingClient.Get(ing.Name, metav1.GetOptions{})
+	ingClient := lbc.client.Extensions().Ingresses(namespace)
+	currIng, err := ingClient.Get(name, metav1.GetOptions{})
 	if err != nil {
 		return err
 	}
-	currIng.Annotations = loadbalancers.GetLBAnnotations(l7, currIng.Annotations, lbc.CloudClusterManager.backendPool)
-	if !reflect.DeepEqual(ing.Annotations, currIng.Annotations) {
-		glog.V(3).Infof("Updating annotations of %v/%v", ing.Namespace, ing.Name)
+	if !reflect.DeepEqual(currIng.Annotations, annotations) {
+		glog.V(3).Infof("Updating annotations of %v/%v", namespace, name)
+		currIng.Annotations = annotations
 		if _, err := ingClient.Update(currIng); err != nil {
 			return err
 		}

controllers/gce/controller/utils.go

@@ -26,6 +26,7 @@ import (
 	"github.com/golang/glog"
 
 	compute "google.golang.org/api/compute/v1"
+
 	api_v1 "k8s.io/api/core/v1"
 	extensions "k8s.io/api/extensions/v1beta1"
 	"k8s.io/apimachinery/pkg/api/meta"
@@ -77,10 +78,17 @@ const (
 	// to either gceIngessClass or the empty string.
 	ingressClassKey      = "kubernetes.io/ingress.class"
 	gceIngressClass      = "gce"
+	gceMultiIngressClass = "gce-multi-cluster"
 
 	// Label key to denote which GCE zone a Kubernetes node is in.
 	zoneKey     = "failure-domain.beta.kubernetes.io/zone"
 	defaultZone = ""
+
+	// instanceGroupsAnnotationKey is the annotation key used by controller to
+	// specify the name and zone of instance groups created for the ingress.
+	// This is read only for users. Controller will overrite any user updates.
+	// This is only set for ingresses with ingressClass = "gce-multi-cluster"
+	instanceGroupsAnnotationKey = "ingress.gcp.kubernetes.io/instance-groups"
 )
 
 // ingAnnotations represents Ingress annotations.
@@ -156,6 +164,13 @@ func isGCEIngress(ing *extensions.Ingress) bool {
 	return class == "" || class == gceIngressClass
 }
 
+// isGCEMultiClusterIngress returns true if the given Ingress has
+// ingress.class annotation set to "gce-multi-cluster".
+func isGCEMultiClusterIngress(ing *extensions.Ingress) bool {
+	class := ingAnnotations(ing.ObjectMeta.Annotations).ingressClass()
+	return class == gceMultiIngressClass
+}
+
 // errorNodePortNotFound is an implementation of error.
 type errorNodePortNotFound struct {
 	backend extensions.IngressBackend
@@ -471,10 +486,18 @@ PortLoop:
 	return p, nil
 }
 
-// toNodePorts converts a pathlist to a flat list of nodeports.
+// toNodePorts is a helper method over ingressToNodePorts to process a list of ingresses.
 func (t *GCETranslator) toNodePorts(ings *extensions.IngressList) []backends.ServicePort {
 	var knownPorts []backends.ServicePort
 	for _, ing := range ings.Items {
+		knownPorts = append(knownPorts, t.ingressToNodePorts(&ing)...)
+	}
+	return knownPorts
+}
+
+// ingressToNodePorts converts a pathlist to a flat list of nodeports for the given ingress.
+func (t *GCETranslator) ingressToNodePorts(ing *extensions.Ingress) []backends.ServicePort {
+	var knownPorts []backends.ServicePort
 	defaultBackend := ing.Spec.Backend
 	if defaultBackend != nil {
 		port, err := t.getServiceNodePort(*defaultBackend, ing.Namespace)
@@ -487,18 +510,17 @@ func (t *GCETranslator) toNodePorts(ings *extensions.IngressList) []backends.Ser
 	for _, rule := range ing.Spec.Rules {
 		if rule.HTTP == nil {
 			glog.Errorf("ignoring non http Ingress rule")
-				continue
+			return knownPorts
 		}
 		for _, path := range rule.HTTP.Paths {
 			port, err := t.getServiceNodePort(path.Backend, ing.Namespace)
 			if err != nil {
 				glog.Infof("%v", err)
-					continue
+				return knownPorts
 			}
 			knownPorts = append(knownPorts, port)
 		}
 	}
-	}
 	return knownPorts
 }
 
@@ -640,3 +662,21 @@ func (o PodsByCreationTimestamp) Less(i, j int) bool {
 	}
 	return o[i].CreationTimestamp.Before(o[j].CreationTimestamp)
 }
+
+// setInstanceGroupsAnnotation sets the instance-groups annotation with names of the given instance groups.
+func setInstanceGroupsAnnotation(existing map[string]string, igs []*compute.InstanceGroup) error {
+	type Value struct {
+		Name string
+		Zone string
+	}
+	instanceGroups := []Value{}
+	for _, ig := range igs {
+		instanceGroups = append(instanceGroups, Value{Name: ig.Name, Zone: ig.Zone})
+	}
+	jsonValue, err := json.Marshal(instanceGroups)
+	if err != nil {
+		return err
+	}
+	existing[instanceGroupsAnnotationKey] = string(jsonValue)
+	return nil
+}

controllers/gce/controller/utils_test.go

@@ -21,6 +21,8 @@ import (
 	"testing"
 	"time"
 
+	compute "google.golang.org/api/compute/v1"
+
 	api_v1 "k8s.io/api/core/v1"
 	meta_v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
@@ -263,3 +265,43 @@ func addNodes(lbc *LoadBalancerController, zoneToNode map[string][]string) {
 func getProbePath(p *api_v1.Probe) string {
 	return p.Handler.HTTPGet.Path
 }
+
+func TestAddInstanceGroupsAnnotation(t *testing.T) {
+	testCases := []struct {
+		Igs                []*compute.InstanceGroup
+		ExpectedAnnotation string
+	}{
+		{
+			// Single zone.
+			[]*compute.InstanceGroup{&compute.InstanceGroup{
+				Name: "ig-name",
+				Zone: "https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-b",
+			}},
+			`[{"Name":"ig-name","Zone":"https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-b"}]`,
+		},
+		{
+			// Multiple zones.
+			[]*compute.InstanceGroup{
+				&compute.InstanceGroup{
+					Name: "ig-name-1",
+					Zone: "https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-b",
+				},
+				&compute.InstanceGroup{
+					Name: "ig-name-2",
+					Zone: "https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-a",
+				},
+			},
+			`[{"Name":"ig-name-1","Zone":"https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-b"},{"Name":"ig-name-2","Zone":"https://www.googleapis.com/compute/v1/projects/my-project/zones/us-central1-a"}]`,
+		},
+	}
+	for _, c := range testCases {
+		annotations := map[string]string{}
+		err := setInstanceGroupsAnnotation(annotations, c.Igs)
+		if err != nil {
+			t.Fatalf("Unexpected error: %v", err)
+		}
+		if annotations[instanceGroupsKey] != c.ExpectedAnnotation {
+			t.Fatalf("Unexpected annotation value: %s, expected: %s", annotations[instanceGroupsKey], c.ExpectedAnnotation)
+		}
+	}
+}

controllers/gce/instances/utils.go

@@ -0,0 +1,13 @@
+package instances
+
+import (
+	compute "google.golang.org/api/compute/v1"
+
+	"k8s.io/ingress/controllers/gce/utils"
+)
+
+// Helper method to create instance groups.
+// This method exists to ensure that we are using the same logic at all places.
+func CreateInstanceGroups(nodePool NodePool, namer *utils.Namer, port int64) ([]*compute.InstanceGroup, *compute.NamedPort, error) {
+	return nodePool.AddInstanceGroup(namer.IGName(), port)
+}