Add nodeHasControlPlanePods()

DeprecatedMightBeMasterNode() has been marked as deprecated and we need to
find alternative way for callers of the function.
In NewResourceUsageGatherer(), the function was called for distinguishing
the specified pods are running on master nodes, and the gatherer gathers
those pods' resource usage.
This adds nodeHasControlPlanePods() to gistinguish the specified pods
are running on nodes which are operating control plane pods (kube-scheduler
and kube-controller-manager) and replace callers of DeprecatedMightBeMasterNode()
with this new function as better way.

Author: Kenichi Omichi

test/e2e/framework/BUILD

@@ -65,7 +65,6 @@ go_library(
         "//test/e2e/framework/node:go_default_library",
         "//test/e2e/framework/pod:go_default_library",
         "//test/e2e/framework/ssh:go_default_library",
-        "//test/e2e/system:go_default_library",
         "//test/utils:go_default_library",
         "//test/utils/image:go_default_library",
         "//vendor/github.com/onsi/ginkgo:go_default_library",

test/e2e/framework/resource_usage_gatherer.go

@@ -23,6 +23,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"math"
+	"regexp"
 	"sort"
 	"strconv"
 	"strings"
@@ -32,10 +33,10 @@ import (
 
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientset "k8s.io/client-go/kubernetes"
 	kubeletstatsv1alpha1 "k8s.io/kubernetes/pkg/kubelet/apis/stats/v1alpha1"
-	"k8s.io/kubernetes/test/e2e/system"
 
 	// TODO: Remove the following imports (ref: https://github.com/kubernetes/kubernetes/issues/81245)
 	e2essh "k8s.io/kubernetes/test/e2e/framework/ssh"
@@ -370,6 +371,29 @@ const (
 	MasterAndDNSNodes NodesSet = 2
 )
 
+// nodeHasControlPlanePods returns true if specified node has control plane pods
+// (kube-scheduler and/or kube-controller-manager).
+func nodeHasControlPlanePods(c clientset.Interface, nodeName string) (bool, error) {
+	regKubeScheduler := regexp.MustCompile("kube-scheduler-.*")
+	regKubeControllerManager := regexp.MustCompile("kube-controller-manager-.*")
+
+	podList, err := c.CoreV1().Pods(metav1.NamespaceSystem).List(context.TODO(), metav1.ListOptions{
+		FieldSelector: fields.OneTermEqualSelector("spec.nodeName", nodeName).String(),
+	})
+	if err != nil {
+		return false, err
+	}
+	if len(podList.Items) < 1 {
+		Logf("Can't find any pods in namespace %s to grab metrics from", metav1.NamespaceSystem)
+	}
+	for _, pod := range podList.Items {
+		if regKubeScheduler.MatchString(pod.Name) || regKubeControllerManager.MatchString(pod.Name) {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
 // NewResourceUsageGatherer returns a new ContainerResourceGatherer.
 func NewResourceUsageGatherer(c clientset.Interface, options ResourceGathererOptions, pods *v1.PodList) (*ContainerResourceGatherer, error) {
 	g := ContainerResourceGatherer{
@@ -404,11 +428,23 @@ func NewResourceUsageGatherer(c clientset.Interface, options ResourceGathererOpt
 	}
 	dnsNodes := make(map[string]bool)
 	for _, pod := range pods.Items {
-		if (options.Nodes == MasterNodes) && !system.DeprecatedMightBeMasterNode(pod.Spec.NodeName) {
-			continue
+		if options.Nodes == MasterNodes {
+			isControlPlane, err := nodeHasControlPlanePods(c, pod.Spec.NodeName)
+			if err != nil {
+				return nil, err
+			}
+			if !isControlPlane {
+				continue
+			}
 		}
-		if (options.Nodes == MasterAndDNSNodes) && !system.DeprecatedMightBeMasterNode(pod.Spec.NodeName) && pod.Labels["k8s-app"] != "kube-dns" {
-			continue
+		if options.Nodes == MasterAndDNSNodes {
+			isControlPlane, err := nodeHasControlPlanePods(c, pod.Spec.NodeName)
+			if err != nil {
+				return nil, err
+			}
+			if !isControlPlane && pod.Labels["k8s-app"] != "kube-dns" {
+				continue
+			}
 		}
 		for _, container := range pod.Status.InitContainerStatuses {
 			g.containerIDs = append(g.containerIDs, container.Name)
@@ -427,7 +463,11 @@ func NewResourceUsageGatherer(c clientset.Interface, options ResourceGathererOpt
 	}
 
 	for _, node := range nodeList.Items {
-		if options.Nodes == AllNodes || system.DeprecatedMightBeMasterNode(node.Name) || dnsNodes[node.Name] {
+		isControlPlane, err := nodeHasControlPlanePods(c, node.Name)
+		if err != nil {
+			return nil, err
+		}
+		if options.Nodes == AllNodes || isControlPlane || dnsNodes[node.Name] {
 			g.workerWg.Add(1)
 			g.workers = append(g.workers, resourceGatherWorker{
 				c:                           c,