feat: set transform to strip managedfields for informer (#2149)

* feat: set transform to strip managedfields for informer

Author: vie-serendipity

cmd/yurt-manager/app/manager.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
+	"k8s.io/apimachinery/pkg/api/meta"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/util/wait"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
@@ -34,6 +35,7 @@ import (
 	"k8s.io/klog/v2"
 	"k8s.io/klog/v2/klogr"
 	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/cache"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	metricsserver "sigs.k8s.io/controller-runtime/pkg/metrics/server"
@@ -175,6 +177,14 @@ func Run(c *config.CompletedConfig, stopCh <-chan struct{}) error {
 		metricsServerOpts.ExtraHandlers[path] = handler
 	}
 
+	trimManagedFields := func(obj interface{}) (interface{}, error) {
+		if accessor, err := meta.Accessor(obj); err == nil {
+			if accessor.GetManagedFields() != nil {
+				accessor.SetManagedFields(nil)
+			}
+		}
+		return obj, nil
+	}
 	mgr, err := ctrl.NewManager(cfg, ctrl.Options{
 		Scheme:                     scheme,
 		Metrics:                    metricsServerOpts,
@@ -189,6 +199,9 @@ func Run(c *config.CompletedConfig, stopCh <-chan struct{}) error {
 			CertDir: util.GetCertDir(),
 		}),
 		Logger: setupLog,
+		Cache: cache.Options{
+			DefaultTransform: trimManagedFields,
+		},
 	})
 	if err != nil {
 		setupLog.Error(err, "unable to start manager")

cmd/yurthub/app/config/config.go

@@ -46,6 +46,7 @@ import (
 
 	"github.com/openyurtio/openyurt/cmd/yurthub/app/options"
 	"github.com/openyurtio/openyurt/pkg/projectinfo"
+	pkgutil "github.com/openyurtio/openyurt/pkg/util"
 	"github.com/openyurtio/openyurt/pkg/yurthub/cachemanager"
 	"github.com/openyurtio/openyurt/pkg/yurthub/certificate"
 	certificatemgr "github.com/openyurtio/openyurt/pkg/yurthub/certificate/manager"
@@ -277,19 +278,24 @@ func registerInformers(options *options.YurtHubOptions,
 	informerFactory informers.SharedInformerFactory,
 	workingMode util.WorkingMode,
 	tenantNs string) {
+
 	// configmap informer is used by Yurthub filter approver
 	newConfigmapInformer := func(client kubernetes.Interface, resyncPeriod time.Duration) cache.SharedIndexInformer {
 		tweakListOptions := func(options *metav1.ListOptions) {
 			options.FieldSelector = fields.Set{"metadata.name": util.YurthubConfigMapName}.String()
 		}
-		return coreinformers.NewFilteredConfigMapInformer(client, options.YurtHubNamespace, resyncPeriod, nil, tweakListOptions)
+		informer := coreinformers.NewFilteredConfigMapInformer(client, options.YurtHubNamespace, resyncPeriod, nil, tweakListOptions)
+		informer.SetTransform(pkgutil.TransformStripManagedFields())
+		return informer
 	}
 	informerFactory.InformerFor(&corev1.ConfigMap{}, newConfigmapInformer)
 
 	// secret informer is used by Tenant manager, this feature is not enabled in general.
 	if tenantNs != "" {
 		newSecretInformer := func(client kubernetes.Interface, resyncPeriod time.Duration) cache.SharedIndexInformer {
-			return coreinformers.NewFilteredSecretInformer(client, tenantNs, resyncPeriod, nil, nil)
+			informer := coreinformers.NewFilteredSecretInformer(client, tenantNs, resyncPeriod, nil, nil)
+			informer.SetTransform(pkgutil.TransformStripManagedFields())
+			return informer
 		}
 		informerFactory.InformerFor(&corev1.Secret{}, newSecretInformer)
 	}
@@ -300,10 +306,20 @@ func registerInformers(options *options.YurtHubOptions,
 			listOptions := func(ops *metav1.ListOptions) {
 				ops.FieldSelector = fields.Set{"spec.nodeName": options.NodeName}.String()
 			}
-			return coreinformers.NewFilteredPodInformer(client, "", resyncPeriod, nil, listOptions)
+			informer := coreinformers.NewFilteredPodInformer(client, "", resyncPeriod, nil, listOptions)
+			informer.SetTransform(pkgutil.TransformStripManagedFields())
+			return informer
 		}
 		informerFactory.InformerFor(&corev1.Pod{}, newPodInformer)
 	}
+
+	// service informer is used by serviceTopologyFilter
+	newServiceInformer := func(client kubernetes.Interface, resyncPeriod time.Duration) cache.SharedIndexInformer {
+		informer := coreinformers.NewFilteredServiceInformer(client, "", resyncPeriod, nil, nil)
+		informer.SetTransform(pkgutil.TransformStripManagedFields())
+		return informer
+	}
+	informerFactory.InformerFor(&corev1.Service{}, newServiceInformer)
 }
 
 func prepareServerServing(options *options.YurtHubOptions, certMgr certificate.YurtCertificateManager, cfg *YurtHubConfiguration) error {

pkg/util/util.go

@@ -16,7 +16,12 @@ limitations under the License.
 
 package util
 
-import "reflect"
+import (
+	"reflect"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/client-go/tools/cache"
+)
 
 func IsNil(i interface{}) bool {
 	if i == nil {
@@ -30,6 +35,18 @@ func IsNil(i interface{}) bool {
 	return false
 }
 
+// Dropping `.metadata.managedFields` to improve memory usage
+func TransformStripManagedFields() cache.TransformFunc {
+	return func(in any) (any, error) {
+		// Nilcheck managed fields to avoid hitting https://github.com/kubernetes/kubernetes/issues/124337
+		if obj, err := meta.Accessor(in); err == nil && obj.GetManagedFields() != nil {
+			obj.SetManagedFields(nil)
+		}
+
+		return in, nil
+	}
+}
+
 const (
 	// HttpHeaderContentType HTTP request header keyword: Content-Type which is used in HTTP request and response
 	// headers to specify the media type of the entity body