fix: factorise confimap informer code (#7667)

Signed-off-by: Charles-Edouard Brétéché <charles.edouard@nirmata.com>
Co-authored-by: shuting <shuting@nirmata.com>
Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>

pkg/controllers/generic/configmap/controller.go

@@ -7,13 +7,11 @@ import (
 
 	"github.com/go-logr/logr"
 	"github.com/kyverno/kyverno/pkg/controllers"
+	"github.com/kyverno/kyverno/pkg/informers"
 	"github.com/kyverno/kyverno/pkg/logging"
 	controllerutils "github.com/kyverno/kyverno/pkg/utils/controller"
 	corev1 "k8s.io/api/core/v1"
 	apierrors "k8s.io/apimachinery/pkg/api/errors"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"k8s.io/apimachinery/pkg/fields"
-	corev1informers "k8s.io/client-go/informers/core/v1"
 	"k8s.io/client-go/kubernetes"
 	corev1listers "k8s.io/client-go/listers/core/v1"
 	"k8s.io/client-go/tools/cache"
@@ -21,8 +19,6 @@ import (
 )
 
 const (
-	// Workers is the number of workers for this controller
-	Workers    = 1
 	maxRetries = 10
 )
 
@@ -57,27 +53,17 @@ func NewController(
 	name string,
 	callback callback,
 ) Controller {
-	indexers := cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}
+	informer := informers.NewConfigMapInformer(client, namespace, name, resyncPeriod)
-	options := func(lo *metav1.ListOptions) {
-		lo.FieldSelector = fields.OneTermEqualSelector(metav1.ObjectNameField, name).String()
-	}
-	informer := corev1informers.NewFilteredConfigMapInformer(
-		client,
-		namespace,
-		resyncPeriod,
-		indexers,
-		options,
-	)
 	c := controller{
-		informer:       informer,
+		informer:       informer.Informer(),
-		lister:         corev1listers.NewConfigMapLister(informer.GetIndexer()).ConfigMaps(namespace),
+		lister:         informer.Lister().ConfigMaps(namespace),
 		controllerName: controllerName,
 		queue:          workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), controllerName),
 		logger:         logging.ControllerLogger(controllerName),
 		name:           name,
 		callback:       callback,
 	}
-	controllerutils.AddDefaultEventHandlers(c.logger, informer, c.queue)
+	controllerutils.AddDefaultEventHandlers(c.logger, informer.Informer(), c.queue)
 	return &c
 }
 

pkg/informers/configmaps.go

@@ -0,0 +1,46 @@
+package informers
+
+import (
+	"time"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	corev1informers "k8s.io/client-go/informers/core/v1"
+	"k8s.io/client-go/kubernetes"
+	corev1listers "k8s.io/client-go/listers/core/v1"
+	"k8s.io/client-go/tools/cache"
+)
+
+type configMapInformer struct {
+	informer cache.SharedIndexInformer
+	lister   corev1listers.ConfigMapLister
+}
+
+func NewConfigMapInformer(
+	client kubernetes.Interface,
+	namespace string,
+	name string,
+	resyncPeriod time.Duration,
+) corev1informers.ConfigMapInformer {
+	indexers := cache.Indexers{cache.NamespaceIndex: cache.MetaNamespaceIndexFunc}
+	options := func(lo *metav1.ListOptions) {
+		lo.FieldSelector = fields.OneTermEqualSelector(metav1.ObjectNameField, name).String()
+	}
+	informer := corev1informers.NewFilteredConfigMapInformer(
+		client,
+		namespace,
+		resyncPeriod,
+		indexers,
+		options,
+	)
+	lister := corev1listers.NewConfigMapLister(informer.GetIndexer())
+	return &configMapInformer{informer, lister}
+}
+
+func (i *configMapInformer) Informer() cache.SharedIndexInformer {
+	return i.informer
+}
+
+func (i *configMapInformer) Lister() corev1listers.ConfigMapLister {
+	return i.lister
+}