refactor(controller): use kubernetes informers provided by client-go (#3080)

* refactor(controller): use kubernetes informers provided by client-go
* forgot assigning struct field member

---------

Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

pkg/controller/controller.go

@@ -26,6 +26,7 @@ import (
 	rbacv1 "k8s.io/api/rbac/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
+	informers_core_v1 "k8s.io/client-go/informers/core/v1"
 	"k8s.io/client-go/kubernetes/scheme"
 	typedcorev1 "k8s.io/client-go/kubernetes/typed/core/v1"
 	"k8s.io/client-go/tools/cache"
@@ -401,16 +402,8 @@ func (c *Controller) initSharedInformers() {
 	}
 
 	// Pods
-	podLw := &cache.ListWatch{
+	c.podInformer = informers_core_v1.NewPodInformer(c.KubeClient.Clientset,
-		ListFunc:  c.podListFunc,
+		c.opConfig.WatchedNamespace, constants.QueueResyncPeriodPod, cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
-		WatchFunc: c.podWatchFunc,
-	}
-
-	c.podInformer = cache.NewSharedIndexInformer(
-		podLw,
-		&v1.Pod{},
-		constants.QueueResyncPeriodPod,
-		cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
 
 	c.podInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{
 		AddFunc:    c.podAdd,
@@ -419,15 +412,7 @@ func (c *Controller) initSharedInformers() {
 	})
 
 	// Kubernetes Nodes
-	nodeLw := &cache.ListWatch{
+	c.nodesInformer = informers_core_v1.NewNodeInformer(c.KubeClient.Clientset, constants.QueueResyncPeriodNode,
-		ListFunc:  c.nodeListFunc,
-		WatchFunc: c.nodeWatchFunc,
-	}
-
-	c.nodesInformer = cache.NewSharedIndexInformer(
-		nodeLw,
-		&v1.Node{},
-		constants.QueueResyncPeriodNode,
 		cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc})
 
 	c.nodesInformer.AddEventHandler(cache.ResourceEventHandlerFuncs{

pkg/controller/node.go

@@ -9,33 +9,11 @@ import (
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/watch"
 
 	"github.com/zalando/postgres-operator/pkg/cluster"
 	"github.com/zalando/postgres-operator/pkg/util"
 )
 
-func (c *Controller) nodeListFunc(options metav1.ListOptions) (runtime.Object, error) {
-	opts := metav1.ListOptions{
-		Watch:           options.Watch,
-		ResourceVersion: options.ResourceVersion,
-		TimeoutSeconds:  options.TimeoutSeconds,
-	}
-
-	return c.KubeClient.Nodes().List(context.TODO(), opts)
-}
-
-func (c *Controller) nodeWatchFunc(options metav1.ListOptions) (watch.Interface, error) {
-	opts := metav1.ListOptions{
-		Watch:           options.Watch,
-		ResourceVersion: options.ResourceVersion,
-		TimeoutSeconds:  options.TimeoutSeconds,
-	}
-
-	return c.KubeClient.Nodes().Watch(context.TODO(), opts)
-}
-
 func (c *Controller) nodeAdd(obj interface{}) {
 	node, ok := obj.(*v1.Node)
 	if !ok {

pkg/controller/pod.go

@@ -1,12 +1,7 @@
 package controller
 
 import (
-	"context"
-
 	v1 "k8s.io/api/core/v1"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/watch"
 
 	"github.com/zalando/postgres-operator/pkg/cluster"
 	"github.com/zalando/postgres-operator/pkg/spec"
@@ -14,26 +9,6 @@ import (
 	"k8s.io/apimachinery/pkg/types"
 )
 
-func (c *Controller) podListFunc(options metav1.ListOptions) (runtime.Object, error) {
-	opts := metav1.ListOptions{
-		Watch:           options.Watch,
-		ResourceVersion: options.ResourceVersion,
-		TimeoutSeconds:  options.TimeoutSeconds,
-	}
-
-	return c.KubeClient.Pods(c.opConfig.WatchedNamespace).List(context.TODO(), opts)
-}
-
-func (c *Controller) podWatchFunc(options metav1.ListOptions) (watch.Interface, error) {
-	opts := metav1.ListOptions{
-		Watch:           options.Watch,
-		ResourceVersion: options.ResourceVersion,
-		TimeoutSeconds:  options.TimeoutSeconds,
-	}
-
-	return c.KubeClient.Pods(c.opConfig.WatchedNamespace).Watch(context.TODO(), opts)
-}
-
 func (c *Controller) dispatchPodEvent(clusterName spec.NamespacedName, event cluster.PodEvent) {
 	c.clustersMu.RLock()
 	cluster, ok := c.clusters[clusterName]

pkg/util/k8sutil/k8sutil.go

@@ -67,6 +67,7 @@ type KubernetesClient struct {
 	zalandov1.FabricEventStreamsGetter
 
 	RESTClient         rest.Interface
+	Clientset          *kubernetes.Clientset
 	AcidV1ClientSet    *zalandoclient.Clientset
 	Zalandov1ClientSet *zalandoclient.Clientset
 }
@@ -148,6 +149,7 @@ func NewFromConfig(cfg *rest.Config) (KubernetesClient, error) {
 		return kubeClient, fmt.Errorf("could not get clientset: %v", err)
 	}
 
+	kubeClient.Clientset = client
 	kubeClient.PodsGetter = client.CoreV1()
 	kubeClient.ServicesGetter = client.CoreV1()
 	kubeClient.EndpointsGetter = client.CoreV1()