Gate: disallow in-place resize for guaranteed pods on nodes with a static topology policy

New gate "InPlacePodVerticalScalingExclusiveCPUs" is off by default,
but can be enabled to unblock development of Static CPU management alongside
InPlacePodVerticalScaling.

Author: Sotiris Salloumis

pkg/features/kube_features.go

@@ -270,6 +270,14 @@ const (
 	// InPlacePodVerticalScaling also be enabled.
 	InPlacePodVerticalScalingAllocatedStatus featuregate.Feature = "InPlacePodVerticalScalingAllocatedStatus"
 
+	// owner: @tallclair @esotsal
+	// alpha: v1.32
+	//
+	// Allow resource resize for containers in Guaranteed pods with integer CPU requests ( default false ).
+	// Applies only in nodes with InPlacePodVerticalScaling and CPU Manager features enabled, and
+	// CPU Manager Static Policy option set.
+	InPlacePodVerticalScalingExclusiveCPUs featuregate.Feature = "InPlacePodVerticalScalingExclusiveCPUs"
+
 	// owner: @trierra
 	//
 	// Disables the Portworx in-tree driver.

pkg/features/versioned_kube_features.go

@@ -397,6 +397,10 @@ var defaultVersionedKubernetesFeatureGates = map[featuregate.Feature]featuregate
 		{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
 	},
 
+	InPlacePodVerticalScalingExclusiveCPUs: {
+		{Version: version.MustParse("1.32"), Default: false, PreRelease: featuregate.Alpha},
+	},
+
 	InTreePluginPortworxUnregister: {
 		{Version: version.MustParse("1.23"), Default: false, PreRelease: featuregate.Alpha},
 	},

pkg/kubelet/kubelet.go

@@ -2838,6 +2838,21 @@ func isPodResizeInProgress(pod *v1.Pod, podStatus *kubecontainer.PodStatus) bool
 // pod should hold the desired (pre-allocated) spec.
 // Returns true if the resize can proceed.
 func (kl *Kubelet) canResizePod(pod *v1.Pod) (bool, v1.PodResizeStatus) {
+	if v1qos.GetPodQOS(pod) == v1.PodQOSGuaranteed && !utilfeature.DefaultFeatureGate.Enabled(features.InPlacePodVerticalScalingExclusiveCPUs) {
+		if utilfeature.DefaultFeatureGate.Enabled(features.CPUManager) {
+			if kl.containerManager.GetNodeConfig().CPUManagerPolicy == "static" {
+				klog.V(3).InfoS("Resize is infeasible for Guaranteed Pods alongside CPU Manager static policy")
+				return false, v1.PodResizeStatusInfeasible
+			}
+		}
+		if utilfeature.DefaultFeatureGate.Enabled(features.MemoryManager) {
+			if kl.containerManager.GetNodeConfig().ExperimentalMemoryManagerPolicy == "static" {
+				klog.V(3).InfoS("Resize is infeasible for Guaranteed Pods alongside Memory Manager static policy")
+				return false, v1.PodResizeStatusInfeasible
+			}
+		}
+	}
+
 	node, err := kl.getNodeAnyWay()
 	if err != nil {
 		klog.ErrorS(err, "getNodeAnyway function failed")

test/featuregates_linter/test_data/versioned_feature_list.yaml

@@ -522,6 +522,12 @@
     lockToDefault: false
     preRelease: Alpha
     version: "1.32"
+- name: InPlacePodVerticalScalingExclusiveCPUs
+  versionedSpecs:
+  - default: false
+    lockToDefault: false
+    preRelease: Alpha
+    version: "1.32"
 - name: InTreePluginPortworxUnregister
   versionedSpecs:
   - default: false