From df48ee49d895908725825cb55695bf9ddfee9839 Mon Sep 17 00:00:00 2001
From: Geon-Ju Kim <geonju42@gmail.com>
Date: Sat, 6 Mar 2021 07:58:56 +0900
Subject: [PATCH] Count pod overhead as an entity's resource usage

---
 pkg/quota/v1/evaluator/core/pods.go      |  4 ++
 pkg/quota/v1/evaluator/core/pods_test.go | 64 +++++++++++++++++++++++-
 2 files changed, 66 insertions(+), 2 deletions(-)

diff --git a/pkg/quota/v1/evaluator/core/pods.go b/pkg/quota/v1/evaluator/core/pods.go
index ed44323e27e..6051d24eb85 100644
--- a/pkg/quota/v1/evaluator/core/pods.go
+++ b/pkg/quota/v1/evaluator/core/pods.go
@@ -354,6 +354,10 @@ func PodUsageFunc(obj runtime.Object, clock clock.Clock) (corev1.ResourceList, e
 		limits = quota.Max(limits, pod.Spec.InitContainers[i].Resources.Limits)
 	}
 
+	if feature.DefaultFeatureGate.Enabled(features.PodOverhead) {
+		requests = quota.Add(requests, pod.Spec.Overhead)
+		limits = quota.Add(limits, pod.Spec.Overhead)
+	}
 	result = quota.Add(result, podComputeUsageHelper(requests, limits))
 	return result, nil
 }
diff --git a/pkg/quota/v1/evaluator/core/pods_test.go b/pkg/quota/v1/evaluator/core/pods_test.go
index cd41719ed50..556b7b349f6 100644
--- a/pkg/quota/v1/evaluator/core/pods_test.go
+++ b/pkg/quota/v1/evaluator/core/pods_test.go
@@ -95,8 +95,9 @@ func TestPodEvaluatorUsage(t *testing.T) {
 	deletionTimestampNotPastGracePeriod := metav1.NewTime(fakeClock.Now())
 
 	testCases := map[string]struct {
-		pod   *api.Pod
-		usage corev1.ResourceList
+		pod                *api.Pod
+		usage              corev1.ResourceList
+		podOverheadEnabled bool
 	}{
 		"init container CPU": {
 			pod: &api.Pod{
@@ -438,9 +439,68 @@ func TestPodEvaluatorUsage(t *testing.T) {
 				generic.ObjectCountQuotaResourceNameFor(schema.GroupResource{Resource: "pods"}): resource.MustParse("1"),
 			},
 		},
+		"count pod overhead as usage": {
+			pod: &api.Pod{
+				Spec: api.PodSpec{
+					Overhead: api.ResourceList{
+						api.ResourceCPU: resource.MustParse("1"),
+					},
+					Containers: []api.Container{
+						{
+							Resources: api.ResourceRequirements{
+								Requests: api.ResourceList{
+									api.ResourceCPU: resource.MustParse("1"),
+								},
+								Limits: api.ResourceList{
+									api.ResourceCPU: resource.MustParse("2"),
+								},
+							},
+						},
+					},
+				},
+			},
+			usage: corev1.ResourceList{
+				corev1.ResourceRequestsCPU: resource.MustParse("2"),
+				corev1.ResourceLimitsCPU:   resource.MustParse("3"),
+				corev1.ResourcePods:        resource.MustParse("1"),
+				corev1.ResourceCPU:         resource.MustParse("2"),
+				generic.ObjectCountQuotaResourceNameFor(schema.GroupResource{Resource: "pods"}): resource.MustParse("1"),
+			},
+			podOverheadEnabled: true,
+		},
+		"do not count pod overhead as usage with pod overhead disabled": {
+			pod: &api.Pod{
+				Spec: api.PodSpec{
+					Overhead: api.ResourceList{
+						api.ResourceCPU: resource.MustParse("1"),
+					},
+					Containers: []api.Container{
+						{
+							Resources: api.ResourceRequirements{
+								Requests: api.ResourceList{
+									api.ResourceCPU: resource.MustParse("1"),
+								},
+								Limits: api.ResourceList{
+									api.ResourceCPU: resource.MustParse("2"),
+								},
+							},
+						},
+					},
+				},
+			},
+			usage: corev1.ResourceList{
+				corev1.ResourceRequestsCPU: resource.MustParse("1"),
+				corev1.ResourceLimitsCPU:   resource.MustParse("2"),
+				corev1.ResourcePods:        resource.MustParse("1"),
+				corev1.ResourceCPU:         resource.MustParse("1"),
+				generic.ObjectCountQuotaResourceNameFor(schema.GroupResource{Resource: "pods"}): resource.MustParse("1"),
+			},
+			podOverheadEnabled: false,
+		},
 	}
 	for testName, testCase := range testCases {
 		t.Run(testName, func(t *testing.T) {
+			defer featuregatetesting.SetFeatureGateDuringTest(t, feature.DefaultFeatureGate, features.PodOverhead, testCase.podOverheadEnabled)()
 			actual, err := evaluator.Usage(testCase.pod)
 			if err != nil {
 				t.Error(err)