don't watch headless services on kubelet

The kubelet watches services only to generate the environment variables
inside a pod, but headless services are not needed for this.

Change-Id: I22ee2b3352f8fe71cddfafa6f09b768c0a0e26b4

pkg/kubelet/kubelet.go

@@ -451,7 +451,11 @@ func NewMainKubelet(kubeCfg *kubeletconfiginternal.KubeletConfiguration,
 	var serviceLister corelisters.ServiceLister
 	var serviceHasSynced cache.InformerSynced
 	if kubeDeps.KubeClient != nil {
-		kubeInformers := informers.NewSharedInformerFactoryWithOptions(kubeDeps.KubeClient, 0)
+		// don't watch headless services, they are not needed since this informer is only used to create the environment variables for pods.
+		// See https://issues.k8s.io/122394
+		kubeInformers := informers.NewSharedInformerFactoryWithOptions(kubeDeps.KubeClient, 0, informers.WithTweakListOptions(func(options *metav1.ListOptions) {
+			options.FieldSelector = fields.OneTermNotEqualSelector("spec.clusterIP", v1.ClusterIPNone).String()
+		}))
 		serviceLister = kubeInformers.Core().V1().Services().Lister()
 		serviceHasSynced = kubeInformers.Core().V1().Services().Informer().HasSynced
 		kubeInformers.Start(wait.NeverStop)