Remove ExperimentalCriticalPodAnnotation

pkg/controller/daemon/util/daemonset_util.go

@@ -21,7 +21,7 @@ import (
 	"strconv"
 
 	apps "k8s.io/api/apps/v1"
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	extensions "k8s.io/api/extensions/v1beta1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	podutil "k8s.io/kubernetes/pkg/api/v1/pod"

pkg/features/kube_features.go

@@ -47,15 +47,6 @@ const (
 	// SYS_TIME). This should only be enabled if user namespace remapping is enabled in the docker daemon.
 	ExperimentalHostUserNamespaceDefaultingGate utilfeature.Feature = "ExperimentalHostUserNamespaceDefaulting"
 
-	// owner: @vishh
-	// alpha: v1.5
-	//
-	// DEPRECATED - This feature is deprecated by Pod Priority and Preemption as of Kubernetes 1.13.
-	// Ensures guaranteed scheduling of pods marked with a special pod annotation `scheduler.alpha.kubernetes.io/critical-pod`
-	// and also prevents them from being evicted from a node.
-	// Note: This feature is not supported for `BestEffort` pods.
-	ExperimentalCriticalPodAnnotation utilfeature.Feature = "ExperimentalCriticalPodAnnotation"
-
 	// owner: @jiayingz
 	// beta: v1.10
 	//
@@ -446,7 +437,6 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	AppArmor:             {Default: true, PreRelease: utilfeature.Beta},
 	DynamicKubeletConfig: {Default: true, PreRelease: utilfeature.Beta},
 	ExperimentalHostUserNamespaceDefaultingGate: {Default: false, PreRelease: utilfeature.Beta},
-	ExperimentalCriticalPodAnnotation:           {Default: false, PreRelease: utilfeature.Alpha},
 	DevicePlugins:                               {Default: true, PreRelease: utilfeature.Beta},
 	TaintBasedEvictions:                         {Default: true, PreRelease: utilfeature.Beta},
 	RotateKubeletServerCertificate:              {Default: true, PreRelease: utilfeature.Beta},

pkg/kubelet/types/pod_update.go

@@ -22,7 +22,6 @@ import (
 	"k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	utilfeature "k8s.io/apiserver/pkg/util/feature"
-	kubeapi "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/scheduling"
 	"k8s.io/kubernetes/pkg/features"
 )
@@ -32,7 +31,6 @@ const (
 	ConfigMirrorAnnotationKey    = v1.MirrorPodAnnotationKey
 	ConfigFirstSeenAnnotationKey = "kubernetes.io/config.seen"
 	ConfigHashAnnotationKey      = "kubernetes.io/config.hash"
-	CriticalPodAnnotationKey     = "scheduler.alpha.kubernetes.io/critical-pod"
 )
 
 // PodOperation defines what changes will be made on a pod configuration.
@@ -151,11 +149,6 @@ func IsCriticalPod(pod *v1.Pod) bool {
 			return true
 		}
 	}
-	if utilfeature.DefaultFeatureGate.Enabled(features.ExperimentalCriticalPodAnnotation) {
-		if IsCritical(pod.Namespace, pod.Annotations) {
-			return true
-		}
-	}
 	return false
 }
 
@@ -175,21 +168,6 @@ func Preemptable(preemptor, preemptee *v1.Pod) bool {
 	return false
 }
 
-// IsCritical returns true if parameters bear the critical pod annotation
-// key. The DaemonSetController use this key directly to make scheduling decisions.
-// TODO: @ravig - Deprecated. Remove this when we move to resolving critical pods based on priorityClassName.
-func IsCritical(ns string, annotations map[string]string) bool {
-	// Critical pods are restricted to "kube-system" namespace as of now.
-	if ns != kubeapi.NamespaceSystem {
-		return false
-	}
-	val, ok := annotations[CriticalPodAnnotationKey]
-	if ok && val == "" {
-		return true
-	}
-	return false
-}
-
 // IsCriticalPodBasedOnPriority checks if the given pod is a critical pod based on priority resolved from pod Spec.
 func IsCriticalPodBasedOnPriority(priority int32) bool {
 	if priority >= scheduling.SystemCriticalPriority {

plugin/pkg/admission/priority/admission.go

@@ -33,7 +33,6 @@ import (
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/apis/scheduling"
 	"k8s.io/kubernetes/pkg/features"
-	kubelettypes "k8s.io/kubernetes/pkg/kubelet/types"
 )
 
 const (
@@ -179,13 +178,6 @@ func (p *priorityPlugin) admitPod(a admission.Attributes) error {
 
 	if operation == admission.Create {
 		var priority int32
-		// TODO: @ravig - This is for backwards compatibility to ensure that critical pods with annotations just work fine.
-		// Remove when no longer needed.
-		if len(pod.Spec.PriorityClassName) == 0 &&
-			utilfeature.DefaultFeatureGate.Enabled(features.ExperimentalCriticalPodAnnotation) &&
-			kubelettypes.IsCritical(a.GetNamespace(), pod.Annotations) {
-			pod.Spec.PriorityClassName = scheduling.SystemClusterCritical
-		}
 		if len(pod.Spec.PriorityClassName) == 0 {
 			var err error
 			var pcName string