Promote PidLimits to GA

Author: derekwaynecarr

cmd/kubelet/app/server.go

@@ -1248,16 +1248,14 @@ func parseResourceList(m map[string]string) (v1.ResourceList, error) {
 		switch v1.ResourceName(k) {
 		// CPU, memory, local storage, and PID resources are supported.
 		case v1.ResourceCPU, v1.ResourceMemory, v1.ResourceEphemeralStorage, pidlimit.PIDs:
-			if v1.ResourceName(k) != pidlimit.PIDs || utilfeature.DefaultFeatureGate.Enabled(features.SupportNodePidsLimit) {
-				q, err := resource.ParseQuantity(v)
-				if err != nil {
-					return nil, err
-				}
-				if q.Sign() == -1 {
-					return nil, fmt.Errorf("resource quantity for %q cannot be negative: %v", k, v)
-				}
-				rl[v1.ResourceName(k)] = q
+			q, err := resource.ParseQuantity(v)
+			if err != nil {
+				return nil, err
+			}
+			if q.Sign() == -1 {
+				return nil, fmt.Errorf("resource quantity for %q cannot be negative: %v", k, v)
 			}
+			rl[v1.ResourceName(k)] = q
 		default:
 			return nil, fmt.Errorf("cannot reserve %q resource", k)
 		}

pkg/features/kube_features.go

@@ -203,6 +203,7 @@ const (
 	// owner: @dims, @derekwaynecarr
 	// alpha: v1.10
 	// beta: v1.14
+	// GA: v1.20
 	//
 	// Implement support for limiting pids in pods
 	SupportPodPidsLimit featuregate.Feature = "SupportPodPidsLimit"
@@ -447,8 +448,9 @@ const (
 	// a volume in a Pod.
 	ConfigurableFSGroupPolicy featuregate.Feature = "ConfigurableFSGroupPolicy"
 
-	// owner: @RobertKrawitz
+	// owner: @RobertKrawitz, @derekwaynecarr
 	// beta: v1.15
+	// GA: v1.20
 	//
 	// Implement support for limiting pids in nodes
 	SupportNodePidsLimit featuregate.Feature = "SupportNodePidsLimit"
@@ -680,8 +682,8 @@ var defaultKubernetesFeatureGates = map[featuregate.Feature]featuregate.FeatureS
 	BlockVolume:                    {Default: true, PreRelease: featuregate.GA, LockToDefault: true}, // remove in 1.20
 	StorageObjectInUseProtection:   {Default: true, PreRelease: featuregate.GA},
 	SupportIPVSProxyMode:           {Default: true, PreRelease: featuregate.GA},
-	SupportPodPidsLimit:            {Default: true, PreRelease: featuregate.Beta},
-	SupportNodePidsLimit:           {Default: true, PreRelease: featuregate.Beta},
+	SupportPodPidsLimit:            {Default: true, PreRelease: featuregate.GA, LockToDefault: true}, // remove in 1.21
+	SupportNodePidsLimit:           {Default: true, PreRelease: featuregate.GA, LockToDefault: true}, // remove in 1.21
 	HyperVContainer:                {Default: false, PreRelease: featuregate.Alpha},
 	TokenRequest:                   {Default: true, PreRelease: featuregate.Beta},
 	TokenRequestProjection:         {Default: true, PreRelease: featuregate.Beta},

pkg/kubelet/cm/cgroup_manager_linux.go

@@ -36,8 +36,6 @@ import (
 
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	"k8s.io/apimachinery/pkg/util/sets"
-	utilfeature "k8s.io/apiserver/pkg/util/feature"
-	kubefeatures "k8s.io/kubernetes/pkg/features"
 	cmutil "k8s.io/kubernetes/pkg/kubelet/cm/util"
 	"k8s.io/kubernetes/pkg/kubelet/metrics"
 )
@@ -275,11 +273,8 @@ func (m *cgroupManagerImpl) Exists(name CgroupName) bool {
 	// scoped to the set control groups it understands.  this is being discussed
 	// in https://github.com/opencontainers/runc/issues/1440
 	// once resolved, we can remove this code.
-	whitelistControllers := sets.NewString("cpu", "cpuacct", "cpuset", "memory", "systemd")
+	whitelistControllers := sets.NewString("cpu", "cpuacct", "cpuset", "memory", "systemd", "pids")
 
-	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) || utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportNodePidsLimit) {
-		whitelistControllers.Insert("pids")
-	}
 	if _, ok := m.subsystems.MountPoints["hugetlb"]; ok {
 		whitelistControllers.Insert("hugetlb")
 	}
@@ -352,13 +347,10 @@ func getSupportedSubsystems() map[subsystem]bool {
 	supportedSubsystems := map[subsystem]bool{
 		&cgroupfs.MemoryGroup{}: true,
 		&cgroupfs.CpuGroup{}:    true,
-		&cgroupfs.PidsGroup{}:   false,
+		&cgroupfs.PidsGroup{}:   true,
 	}
 	// not all hosts support hugetlb cgroup, and in the absent of hugetlb, we will fail silently by reporting no capacity.
 	supportedSubsystems[&cgroupfs.HugetlbGroup{}] = false
-	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) || utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportNodePidsLimit) {
-		supportedSubsystems[&cgroupfs.PidsGroup{}] = true
-	}
 	return supportedSubsystems
 }
 
@@ -417,10 +409,7 @@ var (
 // getSupportedUnifiedControllers returns a set of supported controllers when running on cgroup v2
 func getSupportedUnifiedControllers() sets.String {
 	// This is the set of controllers used by the Kubelet
-	supportedControllers := sets.NewString("cpu", "cpuset", "memory", "hugetlb")
-	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) || utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportNodePidsLimit) {
-		supportedControllers.Insert("pids")
-	}
+	supportedControllers := sets.NewString("cpu", "cpuset", "memory", "hugetlb", "pids")
 	// Memoize the set of controllers that are present in the root cgroup
 	availableRootControllersOnce.Do(func() {
 		var err error
@@ -547,10 +536,8 @@ func (m *cgroupManagerImpl) toResources(resourceConfig *ResourceConfig) *libcont
 	if resourceConfig.CpuPeriod != nil {
 		resources.CpuPeriod = *resourceConfig.CpuPeriod
 	}
-	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) || utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportNodePidsLimit) {
-		if resourceConfig.PidsLimit != nil {
-			resources.PidsLimit = *resourceConfig.PidsLimit
-		}
+	if resourceConfig.PidsLimit != nil {
+		resources.PidsLimit = *resourceConfig.PidsLimit
 	}
 	// if huge pages are enabled, we set them in libcontainer
 	// for each page size enumerated, set that value
@@ -608,7 +595,7 @@ func (m *cgroupManagerImpl) Update(cgroupConfig *CgroupConfig) error {
 		updateSystemdCgroupInfo(libcontainerCgroupConfig, cgroupConfig.Name)
 	}
 
-	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) && cgroupConfig.ResourceParameters != nil && cgroupConfig.ResourceParameters.PidsLimit != nil {
+	if cgroupConfig.ResourceParameters != nil && cgroupConfig.ResourceParameters.PidsLimit != nil {
 		libcontainerCgroupConfig.PidsLimit = *cgroupConfig.ResourceParameters.PidsLimit
 	}
 
@@ -648,7 +635,7 @@ func (m *cgroupManagerImpl) Create(cgroupConfig *CgroupConfig) error {
 		}
 	}
 
-	if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) && cgroupConfig.ResourceParameters != nil && cgroupConfig.ResourceParameters.PidsLimit != nil {
+	if cgroupConfig.ResourceParameters != nil && cgroupConfig.ResourceParameters.PidsLimit != nil {
 		libcontainerCgroupConfig.PidsLimit = *cgroupConfig.ResourceParameters.PidsLimit
 	}
 

pkg/kubelet/cm/pod_container_manager_linux.go

@@ -26,10 +26,8 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/types"
 	utilerrors "k8s.io/apimachinery/pkg/util/errors"
-	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	"k8s.io/klog/v2"
 	v1qos "k8s.io/kubernetes/pkg/apis/core/v1/helper/qos"
-	kubefeatures "k8s.io/kubernetes/pkg/features"
 )
 
 const (
@@ -86,7 +84,7 @@ func (m *podContainerManagerImpl) EnsureExists(pod *v1.Pod) error {
 			Name:               podContainerName,
 			ResourceParameters: ResourceConfigForPod(pod, m.enforceCPULimits, m.cpuCFSQuotaPeriod),
 		}
-		if utilfeature.DefaultFeatureGate.Enabled(kubefeatures.SupportPodPidsLimit) && m.podPidsLimit > 0 {
+		if m.podPidsLimit > 0 {
 			containerConfig.ResourceParameters.PidsLimit = &m.podPidsLimit
 		}
 		if err := m.cgroupManager.Create(containerConfig); err != nil {

test/e2e_node/pids_test.go

@@ -118,14 +118,13 @@ func runPodPidsLimitTests(f *framework.Framework) {
 }
 
 // Serial because the test updates kubelet configuration.
-var _ = SIGDescribe("PodPidsLimit [Serial] [Feature:SupportPodPidsLimit][NodeFeature:SupportPodPidsLimit]", func() {
+var _ = SIGDescribe("PodPidsLimit [Serial]", func() {
 	f := framework.NewDefaultFramework("pids-limit-test")
 	ginkgo.Context("With config updated with pids feature enabled", func() {
 		tempSetCurrentKubeletConfig(f, func(initialConfig *kubeletconfig.KubeletConfiguration) {
 			if initialConfig.FeatureGates == nil {
 				initialConfig.FeatureGates = make(map[string]bool)
 			}
-			initialConfig.FeatureGates["SupportPodPidsLimit"] = true
 			initialConfig.PodPidsLimit = int64(1024)
 		})
 		runPodPidsLimitTests(f)