Fix a bug where the ResourceQuota admission plugin does not respect ANY scope change when a resource is being updated. i.e. to set/unset an existing pod's terminationGracePeriodSeconds field.

Author: carlory

pkg/quota/v1/evaluator/core/pods.go

@@ -170,6 +170,17 @@ func (p *podEvaluator) Handles(a admission.Attributes) bool {
 	op := a.GetOperation()
 	switch a.GetSubresource() {
 	case "":
+		if op == admission.Update {
+			pod, err1 := toExternalPodOrError(a.GetObject())
+			oldPod, err2 := toExternalPodOrError(a.GetOldObject())
+			if err1 != nil || err2 != nil {
+				return false
+			}
+			// when scope changed
+			if IsTerminating(oldPod) != IsTerminating(pod) {
+				return true
+			}
+		}
 		return op == admission.Create
 	case "resize":
 		return op == admission.Update
@@ -333,9 +344,9 @@ func podMatchesScopeFunc(selector corev1.ScopedResourceSelectorRequirement, obje
 	}
 	switch selector.ScopeName {
 	case corev1.ResourceQuotaScopeTerminating:
-		return isTerminating(pod), nil
+		return IsTerminating(pod), nil
 	case corev1.ResourceQuotaScopeNotTerminating:
-		return !isTerminating(pod), nil
+		return !IsTerminating(pod), nil
 	case corev1.ResourceQuotaScopeBestEffort:
 		return isBestEffort(pod), nil
 	case corev1.ResourceQuotaScopeNotBestEffort:
@@ -393,7 +404,7 @@ func isBestEffort(pod *corev1.Pod) bool {
 	return qos.GetPodQOS(pod) == corev1.PodQOSBestEffort
 }
 
-func isTerminating(pod *corev1.Pod) bool {
+func IsTerminating(pod *corev1.Pod) bool {
 	if pod.Spec.ActiveDeadlineSeconds != nil && *pod.Spec.ActiveDeadlineSeconds >= int64(0) {
 		return true
 	}

pkg/quota/v1/evaluator/core/pods_test.go

@@ -38,6 +38,7 @@ import (
 	"k8s.io/kubernetes/pkg/util/node"
 	"k8s.io/utils/clock"
 	testingclock "k8s.io/utils/clock/testing"
+	"k8s.io/utils/ptr"
 )
 
 func TestPodConstraintsFunc(t *testing.T) {
@@ -1297,6 +1298,21 @@ func TestPodEvaluatorHandles(t *testing.T) {
 			attrs: admission.NewAttributesRecord(nil, nil, schema.GroupVersionKind{Group: "core", Version: "v1", Kind: "Pod"}, "", "", schema.GroupVersionResource{Group: "core", Version: "v1", Resource: "pods"}, "", admission.Create, nil, false, nil),
 			want:  true,
 		},
+		{
+			name:  "update-activeDeadlineSeconds-to-nil",
+			attrs: admission.NewAttributesRecord(&corev1.Pod{}, &corev1.Pod{Spec: corev1.PodSpec{ActiveDeadlineSeconds: ptr.To[int64](1)}}, schema.GroupVersionKind{Group: "core", Version: "v1", Kind: "Pod"}, "", "", schema.GroupVersionResource{Group: "core", Version: "v1", Resource: "pods"}, "", admission.Update, nil, false, nil),
+			want:  true,
+		},
+		{
+			name:  "update-activeDeadlineSeconds-from-nil",
+			attrs: admission.NewAttributesRecord(&corev1.Pod{Spec: corev1.PodSpec{ActiveDeadlineSeconds: ptr.To[int64](1)}}, &corev1.Pod{}, schema.GroupVersionKind{Group: "core", Version: "v1", Kind: "Pod"}, "", "", schema.GroupVersionResource{Group: "core", Version: "v1", Resource: "pods"}, "", admission.Update, nil, false, nil),
+			want:  true,
+		},
+		{
+			name:  "update-activeDeadlineSeconds-with-different-values",
+			attrs: admission.NewAttributesRecord(&corev1.Pod{Spec: corev1.PodSpec{ActiveDeadlineSeconds: ptr.To[int64](1)}}, &corev1.Pod{Spec: corev1.PodSpec{ActiveDeadlineSeconds: ptr.To[int64](2)}}, schema.GroupVersionKind{Group: "core", Version: "v1", Kind: "Pod"}, "", "", schema.GroupVersionResource{Group: "core", Version: "v1", Resource: "pods"}, "", admission.Update, nil, false, nil),
+			want:  false,
+		},
 		{
 			name:  "update",
 			attrs: admission.NewAttributesRecord(nil, nil, schema.GroupVersionKind{Group: "core", Version: "v1", Kind: "Pod"}, "", "", schema.GroupVersionResource{Group: "core", Version: "v1", Resource: "pods"}, "", admission.Update, nil, false, nil),

pkg/quota/v1/install/update_filter.go

@@ -38,6 +38,12 @@ func DefaultUpdateFilter() func(resource schema.GroupVersionResource, oldObj, ne
 			if feature.DefaultFeatureGate.Enabled(features.InPlacePodVerticalScaling) && hasResourcesChanged(oldPod, newPod) {
 				return true
 			}
+
+			// when scope changed
+			if core.IsTerminating(oldPod) != core.IsTerminating(newPod) {
+				return true
+			}
+
 			return core.QuotaV1Pod(oldPod, clock.RealClock{}) && !core.QuotaV1Pod(newPod, clock.RealClock{})
 		case schema.GroupResource{Resource: "services"}:
 			oldService := oldObj.(*v1.Service)

plugin/pkg/admission/resourcequota/admission_test.go

@@ -860,6 +860,128 @@ func TestAdmitBelowTerminatingQuotaLimit(t *testing.T) {
 	}
 }
 
+// TestAdmitBelowTerminatingQuotaLimitWhenPodScopeUpdated ensures that terminating pods are charged to the right quota.
+// It creates a terminating and non-terminating quota, and changes an existing pod to be terminating.
+// It ensures that the terminating quota is incremented, and the non-terminating quota is not.
+//
+// The Quota admission is intended to fail "high" in this case, and depends on a controller reconciling actual persisted
+// use to lower / free the reserved quota. We need always overcount in the admission plugin if something later causes
+// the request to be rejected, so you can not reduce quota with requests that aren't completed.
+func TestAdmitBelowTerminatingQuotaLimitWhenPodScopeUpdated(t *testing.T) {
+	resourceQuotaNonTerminating := &corev1.ResourceQuota{
+		ObjectMeta: metav1.ObjectMeta{Name: "quota-non-terminating", Namespace: "test", ResourceVersion: "124"},
+		Spec: corev1.ResourceQuotaSpec{
+			Scopes: []corev1.ResourceQuotaScope{corev1.ResourceQuotaScopeNotTerminating},
+		},
+		Status: corev1.ResourceQuotaStatus{
+			Hard: corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("3"),
+				corev1.ResourceMemory: resource.MustParse("100Gi"),
+				corev1.ResourcePods:   resource.MustParse("5"),
+			},
+			Used: corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("1"),
+				corev1.ResourceMemory: resource.MustParse("50Gi"),
+				corev1.ResourcePods:   resource.MustParse("3"),
+			},
+		},
+	}
+	resourceQuotaTerminating := &corev1.ResourceQuota{
+		ObjectMeta: metav1.ObjectMeta{Name: "quota-terminating", Namespace: "test", ResourceVersion: "124"},
+		Spec: corev1.ResourceQuotaSpec{
+			Scopes: []corev1.ResourceQuotaScope{corev1.ResourceQuotaScopeTerminating},
+		},
+		Status: corev1.ResourceQuotaStatus{
+			Hard: corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("3"),
+				corev1.ResourceMemory: resource.MustParse("100Gi"),
+				corev1.ResourcePods:   resource.MustParse("5"),
+			},
+			Used: corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("1"),
+				corev1.ResourceMemory: resource.MustParse("50Gi"),
+				corev1.ResourcePods:   resource.MustParse("3"),
+			},
+		},
+	}
+	stopCh := make(chan struct{})
+	defer close(stopCh)
+
+	kubeClient := fake.NewSimpleClientset(resourceQuotaTerminating, resourceQuotaNonTerminating)
+	informerFactory := informers.NewSharedInformerFactory(kubeClient, 0)
+
+	handler, err := createHandler(kubeClient, informerFactory, stopCh)
+	if err != nil {
+		t.Errorf("Error occurred while creating admission plugin: %v", err)
+	}
+
+	err = informerFactory.Core().V1().ResourceQuotas().Informer().GetIndexer().Add(resourceQuotaNonTerminating)
+	if err != nil {
+		t.Errorf("Error occurred while adding resource quota to the indexer: %v", err)
+	}
+	err = informerFactory.Core().V1().ResourceQuotas().Informer().GetIndexer().Add(resourceQuotaTerminating)
+	if err != nil {
+		t.Errorf("Error occurred while adding resource quota to the indexer: %v", err)
+	}
+
+	// old pod belonged to the non-terminating scope, but updated version belongs to the terminating scope
+	existingPod := validPod("allowed-pod", 1, getResourceRequirements(getResourceList("100m", "2Gi"), getResourceList("", "")))
+	existingPod.ResourceVersion = "1"
+	newPod := validPod("allowed-pod", 1, getResourceRequirements(getResourceList("100m", "2Gi"), getResourceList("", "")))
+	activeDeadlineSeconds := int64(30)
+	newPod.Spec.ActiveDeadlineSeconds = &activeDeadlineSeconds
+	err = handler.Validate(context.TODO(), admission.NewAttributesRecord(newPod, existingPod, api.Kind("Pod").WithVersion("version"), newPod.Namespace, newPod.Name, corev1.Resource("pods").WithVersion("version"), "", admission.Update, &metav1.CreateOptions{}, false, nil), nil)
+	if err != nil {
+		t.Errorf("Unexpected error: %v", err)
+	}
+	if len(kubeClient.Actions()) == 0 {
+		t.Errorf("Expected a client action")
+	}
+
+	expectedActionSet := sets.NewString(
+		strings.Join([]string{"update", "resourcequotas", "status"}, "-"),
+	)
+	actionSet := sets.NewString()
+	for _, action := range kubeClient.Actions() {
+		actionSet.Insert(strings.Join([]string{action.GetVerb(), action.GetResource().Resource, action.GetSubresource()}, "-"))
+	}
+	if !actionSet.HasAll(expectedActionSet.List()...) {
+		t.Errorf("Expected actions:\n%v\n but got:\n%v\nDifference:\n%v", expectedActionSet, actionSet, expectedActionSet.Difference(actionSet))
+	}
+
+	decimatedActions := removeListWatch(kubeClient.Actions())
+	lastActionIndex := len(decimatedActions) - 1
+	usage := decimatedActions[lastActionIndex].(testcore.UpdateAction).GetObject().(*corev1.ResourceQuota)
+
+	// ensure only the quota-terminating was updated
+	if usage.Name != resourceQuotaTerminating.Name {
+		t.Errorf("Incremented the wrong quota, expected %v, actual %v", resourceQuotaTerminating.Name, usage.Name)
+	}
+
+	expectedUsage := corev1.ResourceQuota{
+		Status: corev1.ResourceQuotaStatus{
+			Hard: corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("3"),
+				corev1.ResourceMemory: resource.MustParse("100Gi"),
+				corev1.ResourcePods:   resource.MustParse("5"),
+			},
+			Used: corev1.ResourceList{
+				corev1.ResourceCPU:    resource.MustParse("1100m"),
+				corev1.ResourceMemory: resource.MustParse("52Gi"),
+				corev1.ResourcePods:   resource.MustParse("4"),
+			},
+		},
+	}
+	for k, v := range expectedUsage.Status.Used {
+		actual := usage.Status.Used[k]
+		actualValue := actual.String()
+		expectedValue := v.String()
+		if expectedValue != actualValue {
+			t.Errorf("Usage Used: Key: %v, Expected: %v, Actual: %v", k, expectedValue, actualValue)
+		}
+	}
+}
+
 // TestAdmitBelowBestEffortQuotaLimit creates a best effort and non-best effort quota.
 // It verifies that best effort pods are properly scoped to the best effort quota document.
 func TestAdmitBelowBestEffortQuotaLimit(t *testing.T) {

staging/src/k8s.io/apiserver/pkg/admission/plugin/resourcequota/controller.go

@@ -492,16 +492,26 @@ func CheckRequest(quotas []corev1.ResourceQuota, a admission.Attributes, evaluat
 	// as a result, we need to measure the usage of this object for quota
 	// on updates, we need to subtract the previous measured usage
 	// if usage shows no change, just return since it has no impact on quota
-	deltaUsage, err := evaluator.Usage(inputObject)
+	inputUsage, err := evaluator.Usage(inputObject)
 	if err != nil {
 		return quotas, err
 	}
 
 	// ensure that usage for input object is never negative (this would mean a resource made a negative resource requirement)
-	if negativeUsage := quota.IsNegative(deltaUsage); len(negativeUsage) > 0 {
+	if negativeUsage := quota.IsNegative(inputUsage); len(negativeUsage) > 0 {
 		return nil, admission.NewForbidden(a, fmt.Errorf("quota usage is negative for resource(s): %s", prettyPrintResourceNames(negativeUsage)))
 	}
 
+	// initialize a map of delta usage for each interesting quota index.
+	deltaUsageIndexMap := make(map[int]corev1.ResourceList, len(interestingQuotaIndexes))
+	for _, index := range interestingQuotaIndexes {
+		deltaUsageIndexMap[index] = inputUsage
+	}
+	var deltaUsageWhenNoInterestingQuota corev1.ResourceList
+	if admission.Create == a.GetOperation() && len(interestingQuotaIndexes) == 0 {
+		deltaUsageWhenNoInterestingQuota = inputUsage
+	}
+
 	if admission.Update == a.GetOperation() {
 		prevItem := a.GetOldObject()
 		if prevItem == nil {
@@ -511,20 +521,55 @@ func CheckRequest(quotas []corev1.ResourceQuota, a admission.Attributes, evaluat
 		// if we can definitively determine that this is not a case of "create on update",
 		// then charge based on the delta.  Otherwise, bill the maximum
 		metadata, err := meta.Accessor(prevItem)
-		if err == nil && len(metadata.GetResourceVersion()) > 0 {
-			prevUsage, innerErr := evaluator.Usage(prevItem)
-			if innerErr != nil {
-				return quotas, innerErr
+		if err == nil {
+			if len(metadata.GetResourceVersion()) > 0 {
+				prevUsage, innerErr := evaluator.Usage(prevItem)
+				if innerErr != nil {
+					return quotas, innerErr
+				}
+
+				deltaUsage := quota.SubtractWithNonNegativeResult(inputUsage, prevUsage)
+				if len(interestingQuotaIndexes) == 0 {
+					deltaUsageWhenNoInterestingQuota = deltaUsage
+				}
+
+				for _, index := range interestingQuotaIndexes {
+					resourceQuota := quotas[index]
+					match, err := evaluator.Matches(&resourceQuota, prevItem)
+					if err != nil {
+						klog.ErrorS(err, "Error occurred while matching resource quota against the existing object",
+							"resourceQuota", resourceQuota)
+						return quotas, err
+					}
+					if match {
+						deltaUsageIndexMap[index] = deltaUsage
+					}
+				}
+			} else if len(interestingQuotaIndexes) == 0 {
+				deltaUsageWhenNoInterestingQuota = inputUsage
 			}
-			deltaUsage = quota.SubtractWithNonNegativeResult(deltaUsage, prevUsage)
 		}
 	}
 
-	// ignore items in deltaUsage with zero usage
-	deltaUsage = quota.RemoveZeros(deltaUsage)
+	// ignore items in deltaUsageIndexMap with zero usage,
+	// as they will not impact the quota.
+	for index := range deltaUsageIndexMap {
+		deltaUsageIndexMap[index] = quota.RemoveZeros(deltaUsageIndexMap[index])
+		if len(deltaUsageIndexMap[index]) == 0 {
+			delete(deltaUsageIndexMap, index)
+		}
+	}
+
 	// if there is no remaining non-zero usage, short-circuit and return
-	if len(deltaUsage) == 0 {
-		return quotas, nil
+	if len(interestingQuotaIndexes) != 0 {
+		if len(deltaUsageIndexMap) == 0 {
+			return quotas, nil
+		}
+	} else {
+		deltaUsage := quota.RemoveZeros(deltaUsageWhenNoInterestingQuota)
+		if len(deltaUsage) == 0 {
+			return quotas, nil
+		}
 	}
 
 	// verify that for every resource that had limited by default consumption
@@ -557,6 +602,10 @@ func CheckRequest(quotas []corev1.ResourceQuota, a admission.Attributes, evaluat
 
 	for _, index := range interestingQuotaIndexes {
 		resourceQuota := outQuotas[index]
+		deltaUsage, ok := deltaUsageIndexMap[index]
+		if !ok {
+			continue
+		}
 
 		hardResources := quota.ResourceNames(resourceQuota.Status.Hard)
 		requestedUsage := quota.Mask(deltaUsage, hardResources)