Replace k3s cloud provider wrangler controller with core node informer (#2843)

pkg/cloudprovider/cloudprovider.go

 package cloudprovider
 
 import (
-	"context"
 	"io"
 
 	"github.com/rancher/k3s/pkg/version"
-	"github.com/rancher/wrangler-api/pkg/generated/controllers/core"
-	coreclient "github.com/rancher/wrangler-api/pkg/generated/controllers/core/v1"
-	"github.com/rancher/wrangler/pkg/start"
+	"k8s.io/client-go/informers"
+	informercorev1 "k8s.io/client-go/informers/core/v1"
+	"k8s.io/client-go/tools/cache"
 	cloudprovider "k8s.io/cloud-provider"
 )
 
 type k3s struct {
-	NodeCache coreclient.NodeCache
+	nodeInformer          informercorev1.NodeInformer
+	nodeInformerHasSynced cache.InformerSynced
 }
 
+var _ cloudprovider.Interface = &k3s{}
+var _ cloudprovider.InformerUser = &k3s{}
+
 func init() {
 	cloudprovider.RegisterCloudProvider(version.Program, func(config io.Reader) (cloudprovider.Interface, error) {
 		return &k3s{}, nil
@@ -22,11 +25,11 @@ func init() {
 }
 
 func (k *k3s) Initialize(clientBuilder cloudprovider.ControllerClientBuilder, stop <-chan struct{}) {
-	coreFactory := core.NewFactoryFromConfigOrDie(clientBuilder.ConfigOrDie("cloud-controller-manager"))
-
-	go start.All(context.Background(), 1, coreFactory)
+}
 
-	k.NodeCache = coreFactory.Core().V1().Node().Cache()
+func (k *k3s) SetInformers(informerFactory informers.SharedInformerFactory) {
+	k.nodeInformer = informerFactory.Core().V1().Nodes()
+	k.nodeInformerHasSynced = k.nodeInformer.Informer().HasSynced
 }
 
 func (k *k3s) Instances() (cloudprovider.Instances, bool) {

pkg/cloudprovider/instances.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 
+	"github.com/pkg/errors"
 	"github.com/rancher/k3s/pkg/version"
 	"github.com/sirupsen/logrus"
 	corev1 "k8s.io/api/core/v1"
@@ -30,7 +31,11 @@ func (k *k3s) InstanceExistsByProviderID(ctx context.Context, providerID string)
 }
 
 func (k *k3s) InstanceID(ctx context.Context, nodeName types.NodeName) (string, error) {
-	_, err := k.NodeCache.Get(string(nodeName))
+	if k.nodeInformerHasSynced == nil || !k.nodeInformerHasSynced() {
+		return "", errors.New("Node informer has not synced yet")
+	}
+
+	_, err := k.nodeInformer.Lister().Get(string(nodeName))
 	if err != nil {
 		return "", fmt.Errorf("Failed to find node %s: %v", nodeName, err)
 	}
@@ -55,7 +60,11 @@ func (k *k3s) InstanceTypeByProviderID(ctx context.Context, providerID string) (
 
 func (k *k3s) NodeAddresses(ctx context.Context, name types.NodeName) ([]corev1.NodeAddress, error) {
 	addresses := []corev1.NodeAddress{}
-	node, err := k.NodeCache.Get(string(name))
+	if k.nodeInformerHasSynced == nil || !k.nodeInformerHasSynced() {
+		return nil, errors.New("Node informer has not synced yet")
+	}
+
+	node, err := k.nodeInformer.Lister().Get(string(name))
 	if err != nil {
 		return nil, fmt.Errorf("Failed to find node %s: %v", name, err)
 	}