Merge pull request #56240 from shyamjvs/improve-cidr-allocator

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Migrate CIDR allocators to shared node informer

Ref https://github.com/kubernetes/kubernetes/issues/52292

/cc @wojtek-t @bowei

pkg/controller/node/ipam/BUILD

@@ -16,12 +16,15 @@ go_test(
     importpath = "k8s.io/kubernetes/pkg/controller/node/ipam",
     library = ":go_default_library",
     deps = [
+        "//pkg/controller:go_default_library",
         "//pkg/controller/node/ipam/cidrset:go_default_library",
         "//pkg/controller/node/ipam/test:go_default_library",
         "//pkg/controller/testutil:go_default_library",
         "//vendor/k8s.io/api/core/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/apis/meta/v1:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
+        "//vendor/k8s.io/client-go/informers:go_default_library",
+        "//vendor/k8s.io/client-go/informers/core/v1:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/fake:go_default_library",
     ],
 )
@@ -41,6 +44,7 @@ go_library(
     deps = [
         "//pkg/cloudprovider:go_default_library",
         "//pkg/cloudprovider/providers/gce:go_default_library",
+        "//pkg/controller:go_default_library",
         "//pkg/controller/node/ipam/cidrset:go_default_library",
         "//pkg/controller/node/ipam/sync:go_default_library",
         "//pkg/controller/node/util:go_default_library",
@@ -52,12 +56,14 @@ go_library(
         "//vendor/k8s.io/apimachinery/pkg/fields:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/labels:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/types:go_default_library",
+        "//vendor/k8s.io/apimachinery/pkg/util/runtime:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/sets:go_default_library",
         "//vendor/k8s.io/apimachinery/pkg/util/wait:go_default_library",
         "//vendor/k8s.io/client-go/informers/core/v1:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/scheme:go_default_library",
         "//vendor/k8s.io/client-go/kubernetes/typed/core/v1:go_default_library",
+        "//vendor/k8s.io/client-go/listers/core/v1:go_default_library",
         "//vendor/k8s.io/client-go/tools/cache:go_default_library",
         "//vendor/k8s.io/client-go/tools/record:go_default_library",
         "//vendor/k8s.io/metrics/pkg/client/clientset_generated/clientset/scheme:go_default_library",

pkg/controller/node/ipam/cidr_allocator.go

@@ -80,12 +80,12 @@ type CIDRAllocator interface {
 	AllocateOrOccupyCIDR(node *v1.Node) error
 	// ReleaseCIDR releases the CIDR of the removed node
 	ReleaseCIDR(node *v1.Node) error
-	// Register allocator with the nodeInformer for updates.
+	// Run starts all the working logic of the allocator.
-	Register(nodeInformer informers.NodeInformer)
+	Run(stopCh <-chan struct{})
 }
 
 // New creates a new CIDR range allocator.
-func New(kubeClient clientset.Interface, cloud cloudprovider.Interface, allocatorType CIDRAllocatorType, clusterCIDR, serviceCIDR *net.IPNet, nodeCIDRMaskSize int) (CIDRAllocator, error) {
+func New(kubeClient clientset.Interface, cloud cloudprovider.Interface, nodeInformer informers.NodeInformer, allocatorType CIDRAllocatorType, clusterCIDR, serviceCIDR *net.IPNet, nodeCIDRMaskSize int) (CIDRAllocator, error) {
 	nodeList, err := listNodes(kubeClient)
 	if err != nil {
 		return nil, err
@@ -93,9 +93,9 @@ func New(kubeClient clientset.Interface, cloud cloudprovider.Interface, allocato
 
 	switch allocatorType {
 	case RangeAllocatorType:
-		return NewCIDRRangeAllocator(kubeClient, clusterCIDR, serviceCIDR, nodeCIDRMaskSize, nodeList)
+		return NewCIDRRangeAllocator(kubeClient, nodeInformer, clusterCIDR, serviceCIDR, nodeCIDRMaskSize, nodeList)
 	case CloudAllocatorType:
-		return NewCloudCIDRAllocator(kubeClient, cloud)
+		return NewCloudCIDRAllocator(kubeClient, cloud, nodeInformer)
 	default:
 		return nil, fmt.Errorf("Invalid CIDR allocator type: %v", allocatorType)
 	}

pkg/controller/node/ipam/cloud_cidr_allocator.go

@@ -25,9 +25,10 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/apimachinery/pkg/util/wait"
 	informers "k8s.io/client-go/informers/core/v1"
+	corelisters "k8s.io/client-go/listers/core/v1"
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/record"
 
@@ -37,6 +38,7 @@ import (
 	v1core "k8s.io/client-go/kubernetes/typed/core/v1"
 	"k8s.io/kubernetes/pkg/cloudprovider"
 	"k8s.io/kubernetes/pkg/cloudprovider/providers/gce"
+	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/controller/node/util"
 	nodeutil "k8s.io/kubernetes/pkg/util/node"
 )
@@ -49,6 +51,12 @@ type cloudCIDRAllocator struct {
 	client clientset.Interface
 	cloud  *gce.GCECloud
 
+	// nodeLister is able to list/get nodes and is populated by the shared informer passed to
+	// NewCloudCIDRAllocator.
+	nodeLister corelisters.NodeLister
+	// nodesSynced returns true if the node shared informer has been synced at least once.
+	nodesSynced cache.InformerSynced
+
 	// Channel that is used to pass updating Nodes to the background.
 	// This increases the throughput of CIDR assignment by parallelization
 	// and not blocking on long operations (which shouldn't be done from
@@ -64,7 +72,7 @@ type cloudCIDRAllocator struct {
 var _ CIDRAllocator = (*cloudCIDRAllocator)(nil)
 
 // NewCloudCIDRAllocator creates a new cloud CIDR allocator.
-func NewCloudCIDRAllocator(client clientset.Interface, cloud cloudprovider.Interface) (CIDRAllocator, error) {
+func NewCloudCIDRAllocator(client clientset.Interface, cloud cloudprovider.Interface, nodeInformer informers.NodeInformer) (CIDRAllocator, error) {
 	if client == nil {
 		glog.Fatalf("kubeClient is nil when starting NodeController")
 	}
@@ -84,20 +92,45 @@ func NewCloudCIDRAllocator(client clientset.Interface, cloud cloudprovider.Inter
 	ca := &cloudCIDRAllocator{
 		client:            client,
 		cloud:             gceCloud,
+		nodeLister:        nodeInformer.Lister(),
+		nodesSynced:       nodeInformer.Informer().HasSynced,
 		nodeUpdateChannel: make(chan string, cidrUpdateQueueSize),
 		recorder:          recorder,
 		nodesInProcessing: sets.NewString(),
 	}
 
-	for i := 0; i < cidrUpdateWorkers; i++ {
+	nodeInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
-		// TODO: Take stopChan as an argument to NewCloudCIDRAllocator and pass it to the worker.
+		AddFunc: util.CreateAddNodeHandler(ca.AllocateOrOccupyCIDR),
-		go ca.worker(wait.NeverStop)
+		UpdateFunc: util.CreateUpdateNodeHandler(func(_, newNode *v1.Node) error {
-	}
+			if newNode.Spec.PodCIDR == "" {
+				return ca.AllocateOrOccupyCIDR(newNode)
+			}
+			return nil
+		}),
+		DeleteFunc: util.CreateDeleteNodeHandler(ca.ReleaseCIDR),
+	})
 
 	glog.V(0).Infof("Using cloud CIDR allocator (provider: %v)", cloud.ProviderName())
 	return ca, nil
 }
 
+func (ca *cloudCIDRAllocator) Run(stopCh <-chan struct{}) {
+	defer utilruntime.HandleCrash()
+
+	glog.Infof("Starting cloud CIDR allocator")
+	defer glog.Infof("Shutting down cloud CIDR allocator")
+
+	if !controller.WaitForCacheSync("cidrallocator", stopCh, ca.nodesSynced) {
+		return
+	}
+
+	for i := 0; i < cidrUpdateWorkers; i++ {
+		go ca.worker(stopCh)
+	}
+
+	<-stopCh
+}
+
 func (ca *cloudCIDRAllocator) worker(stopChan <-chan struct{}) {
 	for {
 		select {
@@ -169,7 +202,7 @@ func (ca *cloudCIDRAllocator) updateCIDRAllocation(nodeName string) error {
 
 	for rep := 0; rep < cidrUpdateRetries; rep++ {
 		// TODO: change it to using PATCH instead of full Node updates.
-		node, err = ca.client.CoreV1().Nodes().Get(nodeName, metav1.GetOptions{})
+		node, err = ca.nodeLister.Get(nodeName)
 		if err != nil {
 			glog.Errorf("Failed while getting node %v to retry updating Node.Spec.PodCIDR: %v", nodeName, err)
 			continue
@@ -218,16 +251,3 @@ func (ca *cloudCIDRAllocator) ReleaseCIDR(node *v1.Node) error {
 		node.Name, node.Spec.PodCIDR)
 	return nil
 }
-
-func (ca *cloudCIDRAllocator) Register(nodeInformer informers.NodeInformer) {
-	nodeInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
-		AddFunc: util.CreateAddNodeHandler(ca.AllocateOrOccupyCIDR),
-		UpdateFunc: util.CreateUpdateNodeHandler(func(_, newNode *v1.Node) error {
-			if newNode.Spec.PodCIDR == "" {
-				return ca.AllocateOrOccupyCIDR(newNode)
-			}
-			return nil
-		}),
-		DeleteFunc: util.CreateDeleteNodeHandler(ca.ReleaseCIDR),
-	})
-}

pkg/controller/node/ipam/range_allocator.go

@@ -25,16 +25,16 @@ import (
 
 	"k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
-	"k8s.io/apimachinery/pkg/util/wait"
 	informers "k8s.io/client-go/informers/core/v1"
 	clientset "k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/kubernetes/scheme"
 	v1core "k8s.io/client-go/kubernetes/typed/core/v1"
+	corelisters "k8s.io/client-go/listers/core/v1"
 	"k8s.io/client-go/tools/cache"
 	"k8s.io/client-go/tools/record"
-
+	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/controller/node/ipam/cidrset"
 	"k8s.io/kubernetes/pkg/controller/node/util"
 )
@@ -45,6 +45,12 @@ type rangeAllocator struct {
 	clusterCIDR *net.IPNet
 	maxCIDRs    int
 
+	// nodeLister is able to list/get nodes and is populated by the shared informer passed to
+	// NewCloudCIDRAllocator.
+	nodeLister corelisters.NodeLister
+	// nodesSynced returns true if the node shared informer has been synced at least once.
+	nodesSynced cache.InformerSynced
+
 	// Channel that is used to pass updating Nodes with assigned CIDRs to the background
 	// This increases a throughput of CIDR assignment by not blocking on long operations.
 	nodeCIDRUpdateChannel chan nodeAndCIDR
@@ -59,7 +65,7 @@ type rangeAllocator struct {
 // Caller must ensure subNetMaskSize is not less than cluster CIDR mask size.
 // Caller must always pass in a list of existing nodes so the new allocator
 // can initialize its CIDR map. NodeList is only nil in testing.
-func NewCIDRRangeAllocator(client clientset.Interface, clusterCIDR *net.IPNet, serviceCIDR *net.IPNet, subNetMaskSize int, nodeList *v1.NodeList) (CIDRAllocator, error) {
+func NewCIDRRangeAllocator(client clientset.Interface, nodeInformer informers.NodeInformer, clusterCIDR *net.IPNet, serviceCIDR *net.IPNet, subNetMaskSize int, nodeList *v1.NodeList) (CIDRAllocator, error) {
 	if client == nil {
 		glog.Fatalf("kubeClient is nil when starting NodeController")
 	}
@@ -78,6 +84,8 @@ func NewCIDRRangeAllocator(client clientset.Interface, clusterCIDR *net.IPNet, s
 		client:                client,
 		cidrs:                 set,
 		clusterCIDR:           clusterCIDR,
+		nodeLister:            nodeInformer.Lister(),
+		nodesSynced:           nodeInformer.Informer().HasSynced,
 		nodeCIDRUpdateChannel: make(chan nodeAndCIDR, cidrUpdateQueueSize),
 		recorder:              recorder,
 		nodesInProcessing:     sets.NewString(),
@@ -107,14 +115,57 @@ func NewCIDRRangeAllocator(client clientset.Interface, clusterCIDR *net.IPNet, s
 			}
 		}
 	}
-	for i := 0; i < cidrUpdateWorkers; i++ {
+
-		// TODO: Take stopChan as an argument to NewCIDRRangeAllocator and pass it to the worker.
+	nodeInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
-		go ra.worker(wait.NeverStop)
+		AddFunc: util.CreateAddNodeHandler(ra.AllocateOrOccupyCIDR),
-	}
+		UpdateFunc: util.CreateUpdateNodeHandler(func(_, newNode *v1.Node) error {
+			// If the PodCIDR is not empty we either:
+			// - already processed a Node that already had a CIDR after NC restarted
+			//   (cidr is marked as used),
+			// - already processed a Node successfully and allocated a CIDR for it
+			//   (cidr is marked as used),
+			// - already processed a Node but we did saw a "timeout" response and
+			//   request eventually got through in this case we haven't released
+			//   the allocated CIDR (cidr is still marked as used).
+			// There's a possible error here:
+			// - NC sees a new Node and assigns a CIDR X to it,
+			// - Update Node call fails with a timeout,
+			// - Node is updated by some other component, NC sees an update and
+			//   assigns CIDR Y to the Node,
+			// - Both CIDR X and CIDR Y are marked as used in the local cache,
+			//   even though Node sees only CIDR Y
+			// The problem here is that in in-memory cache we see CIDR X as marked,
+			// which prevents it from being assigned to any new node. The cluster
+			// state is correct.
+			// Restart of NC fixes the issue.
+			if newNode.Spec.PodCIDR == "" {
+				return ra.AllocateOrOccupyCIDR(newNode)
+			}
+			return nil
+		}),
+		DeleteFunc: util.CreateDeleteNodeHandler(ra.ReleaseCIDR),
+	})
 
 	return ra, nil
 }
 
+func (r *rangeAllocator) Run(stopCh <-chan struct{}) {
+	defer utilruntime.HandleCrash()
+
+	glog.Infof("Starting range CIDR allocator")
+	defer glog.Infof("Shutting down range CIDR allocator")
+
+	if !controller.WaitForCacheSync("cidrallocator", stopCh, r.nodesSynced) {
+		return
+	}
+
+	for i := 0; i < cidrUpdateWorkers; i++ {
+		go r.worker(stopCh)
+	}
+
+	<-stopCh
+}
+
 func (r *rangeAllocator) worker(stopChan <-chan struct{}) {
 	for {
 		select {
@@ -232,7 +283,7 @@ func (r *rangeAllocator) updateCIDRAllocation(data nodeAndCIDR) error {
 	podCIDR := data.cidr.String()
 	for rep := 0; rep < cidrUpdateRetries; rep++ {
 		// TODO: change it to using PATCH instead of full Node updates.
-		node, err = r.client.CoreV1().Nodes().Get(data.nodeName, metav1.GetOptions{})
+		node, err = r.nodeLister.Get(data.nodeName)
 		if err != nil {
 			glog.Errorf("Failed while getting node %v to retry updating Node.Spec.PodCIDR: %v", data.nodeName, err)
 			continue
@@ -269,35 +320,3 @@ func (r *rangeAllocator) updateCIDRAllocation(data nodeAndCIDR) error {
 	}
 	return err
 }
-
-func (r *rangeAllocator) Register(nodeInformer informers.NodeInformer) {
-	nodeInformer.Informer().AddEventHandler(cache.ResourceEventHandlerFuncs{
-		AddFunc: util.CreateAddNodeHandler(r.AllocateOrOccupyCIDR),
-		UpdateFunc: util.CreateUpdateNodeHandler(func(_, newNode *v1.Node) error {
-			// If the PodCIDR is not empty we either:
-			// - already processed a Node that already had a CIDR after NC restarted
-			//   (cidr is marked as used),
-			// - already processed a Node successfully and allocated a CIDR for it
-			//   (cidr is marked as used),
-			// - already processed a Node but we did saw a "timeout" response and
-			//   request eventually got through in this case we haven't released
-			//   the allocated CIDR (cidr is still marked as used).
-			// There's a possible error here:
-			// - NC sees a new Node and assigns a CIDR X to it,
-			// - Update Node call fails with a timeout,
-			// - Node is updated by some other component, NC sees an update and
-			//   assigns CIDR Y to the Node,
-			// - Both CIDR X and CIDR Y are marked as used in the local cache,
-			//   even though Node sees only CIDR Y
-			// The problem here is that in in-memory cache we see CIDR X as marked,
-			// which prevents it from being assigned to any new node. The cluster
-			// state is correct.
-			// Restart of NC fixes the issue.
-			if newNode.Spec.PodCIDR == "" {
-				return r.AllocateOrOccupyCIDR(newNode)
-			}
-			return nil
-		}),
-		DeleteFunc: util.CreateDeleteNodeHandler(r.ReleaseCIDR),
-	})
-}

pkg/controller/node/ipam/range_allocator_test.go

@@ -24,7 +24,10 @@ import (
 	"k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/wait"
+	"k8s.io/client-go/informers"
+	coreinformers "k8s.io/client-go/informers/core/v1"
 	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/kubernetes/pkg/controller"
 	"k8s.io/kubernetes/pkg/controller/testutil"
 )
 
@@ -32,6 +35,8 @@ const (
 	nodePollInterval = 100 * time.Millisecond
 )
 
+var alwaysReady = func() bool { return true }
+
 func waitForUpdatedNodeWithTimeout(nodeHandler *testutil.FakeNodeHandler, number int, timeout time.Duration) error {
 	return wait.Poll(nodePollInterval, timeout, func() (bool, error) {
 		if len(nodeHandler.GetUpdatedNodesCopy()) >= number {
@@ -41,6 +46,19 @@ func waitForUpdatedNodeWithTimeout(nodeHandler *testutil.FakeNodeHandler, number
 	})
 }
 
+// Creates a fakeNodeInformer using the provided fakeNodeHandler.
+func getFakeNodeInformer(fakeNodeHandler *testutil.FakeNodeHandler) coreinformers.NodeInformer {
+	fakeClient := &fake.Clientset{}
+	fakeInformerFactory := informers.NewSharedInformerFactory(fakeClient, controller.NoResyncPeriodFunc())
+	fakeNodeInformer := fakeInformerFactory.Core().V1().Nodes()
+
+	for _, node := range fakeNodeHandler.Existing {
+		fakeNodeInformer.Informer().GetStore().Add(node)
+	}
+
+	return fakeNodeInformer
+}
+
 func TestAllocateOrOccupyCIDRSuccess(t *testing.T) {
 	testCases := []struct {
 		description           string
@@ -130,19 +148,23 @@ func TestAllocateOrOccupyCIDRSuccess(t *testing.T) {
 		expectedAllocatedCIDR string
 		allocatedCIDRs        []string
 	}) {
-		allocator, _ := NewCIDRRangeAllocator(tc.fakeNodeHandler, tc.clusterCIDR, tc.serviceCIDR, tc.subNetMaskSize, nil)
+		// Initialize the range allocator.
+		allocator, _ := NewCIDRRangeAllocator(tc.fakeNodeHandler, getFakeNodeInformer(tc.fakeNodeHandler), tc.clusterCIDR, tc.serviceCIDR, tc.subNetMaskSize, nil)
+		rangeAllocator, ok := allocator.(*rangeAllocator)
+		if !ok {
+			t.Logf("%v: found non-default implementation of CIDRAllocator, skipping white-box test...", tc.description)
+			return
+		}
+		rangeAllocator.nodesSynced = alwaysReady
+		rangeAllocator.recorder = testutil.NewFakeRecorder()
+		go allocator.Run(wait.NeverStop)
+
 		// this is a bit of white box testing
 		for _, allocated := range tc.allocatedCIDRs {
 			_, cidr, err := net.ParseCIDR(allocated)
 			if err != nil {
 				t.Fatalf("%v: unexpected error when parsing CIDR %v: %v", tc.description, allocated, err)
 			}
-			rangeAllocator, ok := allocator.(*rangeAllocator)
-			if !ok {
-				t.Logf("%v: found non-default implementation of CIDRAllocator, skipping white-box test...", tc.description)
-				return
-			}
-			rangeAllocator.recorder = testutil.NewFakeRecorder()
 			if err = rangeAllocator.cidrs.Occupy(cidr); err != nil {
 				t.Fatalf("%v: unexpected error when occupying CIDR %v: %v", tc.description, allocated, err)
 			}
@@ -212,19 +234,23 @@ func TestAllocateOrOccupyCIDRFailure(t *testing.T) {
 		subNetMaskSize  int
 		allocatedCIDRs  []string
 	}) {
-		allocator, _ := NewCIDRRangeAllocator(tc.fakeNodeHandler, tc.clusterCIDR, tc.serviceCIDR, tc.subNetMaskSize, nil)
+		// Initialize the range allocator.
+		allocator, _ := NewCIDRRangeAllocator(tc.fakeNodeHandler, getFakeNodeInformer(tc.fakeNodeHandler), tc.clusterCIDR, tc.serviceCIDR, tc.subNetMaskSize, nil)
+		rangeAllocator, ok := allocator.(*rangeAllocator)
+		if !ok {
+			t.Logf("%v: found non-default implementation of CIDRAllocator, skipping white-box test...", tc.description)
+			return
+		}
+		rangeAllocator.nodesSynced = alwaysReady
+		rangeAllocator.recorder = testutil.NewFakeRecorder()
+		go allocator.Run(wait.NeverStop)
+
 		// this is a bit of white box testing
 		for _, allocated := range tc.allocatedCIDRs {
 			_, cidr, err := net.ParseCIDR(allocated)
 			if err != nil {
 				t.Fatalf("%v: unexpected error when parsing CIDR %v: %v", tc.description, allocated, err)
 			}
-			rangeAllocator, ok := allocator.(*rangeAllocator)
-			if !ok {
-				t.Logf("%v: found non-default implementation of CIDRAllocator, skipping white-box test...", tc.description)
-				return
-			}
-			rangeAllocator.recorder = testutil.NewFakeRecorder()
 			err = rangeAllocator.cidrs.Occupy(cidr)
 			if err != nil {
 				t.Fatalf("%v: unexpected error when occupying CIDR %v: %v", tc.description, allocated, err)
@@ -324,19 +350,23 @@ func TestReleaseCIDRSuccess(t *testing.T) {
 		allocatedCIDRs                   []string
 		cidrsToRelease                   []string
 	}) {
-		allocator, _ := NewCIDRRangeAllocator(tc.fakeNodeHandler, tc.clusterCIDR, tc.serviceCIDR, tc.subNetMaskSize, nil)
+		// Initialize the range allocator.
+		allocator, _ := NewCIDRRangeAllocator(tc.fakeNodeHandler, getFakeNodeInformer(tc.fakeNodeHandler), tc.clusterCIDR, tc.serviceCIDR, tc.subNetMaskSize, nil)
+		rangeAllocator, ok := allocator.(*rangeAllocator)
+		if !ok {
+			t.Logf("%v: found non-default implementation of CIDRAllocator, skipping white-box test...", tc.description)
+			return
+		}
+		rangeAllocator.nodesSynced = alwaysReady
+		rangeAllocator.recorder = testutil.NewFakeRecorder()
+		go allocator.Run(wait.NeverStop)
+
 		// this is a bit of white box testing
 		for _, allocated := range tc.allocatedCIDRs {
 			_, cidr, err := net.ParseCIDR(allocated)
 			if err != nil {
 				t.Fatalf("%v: unexpected error when parsing CIDR %v: %v", tc.description, allocated, err)
 			}
-			rangeAllocator, ok := allocator.(*rangeAllocator)
-			if !ok {
-				t.Logf("%v: found non-default implementation of CIDRAllocator, skipping white-box test...", tc.description)
-				return
-			}
-			rangeAllocator.recorder = testutil.NewFakeRecorder()
 			err = rangeAllocator.cidrs.Occupy(cidr)
 			if err != nil {
 				t.Fatalf("%v: unexpected error when occupying CIDR %v: %v", tc.description, allocated, err)

pkg/controller/node/node_controller.go

@@ -360,11 +360,10 @@ func NewNodeController(
 		} else {
 			var err error
 			nc.cidrAllocator, err = ipam.New(
-				kubeClient, cloud, nc.allocatorType, nc.clusterCIDR, nc.serviceCIDR, nodeCIDRMaskSize)
+				kubeClient, cloud, nodeInformer, nc.allocatorType, nc.clusterCIDR, nc.serviceCIDR, nodeCIDRMaskSize)
 			if err != nil {
 				return nil, err
 			}
-			nc.cidrAllocator.Register(nodeInformer)
 		}
 	}
 
@@ -585,6 +584,12 @@ func (nc *Controller) Run(stopCh <-chan struct{}) {
 		go wait.Until(nc.doEvictionPass, scheduler.NodeEvictionPeriod, wait.NeverStop)
 	}
 
+	if nc.allocateNodeCIDRs {
+		if nc.allocatorType != ipam.IPAMFromClusterAllocatorType && nc.allocatorType != ipam.IPAMFromCloudAllocatorType {
+			go nc.cidrAllocator.Run(wait.NeverStop)
+		}
+	}
+
 	<-stopCh
 }