Update actualUsageClient

pkg/framework/plugins/nodeutilization/highnodeutilization.go

@@ -44,7 +44,7 @@ type HighNodeUtilization struct {
 	underutilizationCriteria []interface{}
 	resourceNames            []v1.ResourceName
 	targetThresholds         api.ResourceThresholds
-	usageSnapshot            *usageSnapshot
+	usageSnapshot            usageClient
 }
 
 var _ frameworktypes.BalancePlugin = &HighNodeUtilization{}

pkg/framework/plugins/nodeutilization/lownodeutilization.go

@@ -43,7 +43,7 @@ type LowNodeUtilization struct {
 	underutilizationCriteria []interface{}
 	overutilizationCriteria  []interface{}
 	resourceNames            []v1.ResourceName
-	usageSnapshot            *usageSnapshot
+	usageSnapshot            usageClient
 }
 
 var _ frameworktypes.BalancePlugin = &LowNodeUtilization{}

pkg/framework/plugins/nodeutilization/nodeutilization.go

@@ -74,14 +74,12 @@ func normalizePercentage(percent api.Percentage) api.Percentage {
 	return percent
 }
 
-
-
 func getNodeThresholds(
 	nodes []*v1.Node,
 	lowThreshold, highThreshold api.ResourceThresholds,
 	resourceNames []v1.ResourceName,
 	useDeviationThresholds bool,
-	usageClient *requestedUsageClient,
+	usageClient usageClient,
 ) map[string]NodeThresholds {
 	nodeThresholdsMap := map[string]NodeThresholds{}
 
@@ -123,7 +121,7 @@ func getNodeThresholds(
 
 func getNodeUsage(
 	nodes []*v1.Node,
-	usageClient *requestedUsageClient,
+	usageClient usageClient,
 ) []NodeUsage {
 	var nodeUsageList []NodeUsage
 
@@ -432,7 +430,7 @@ func classifyPods(pods []*v1.Pod, filter func(pod *v1.Pod) bool) ([]*v1.Pod, []*
 	return nonRemovablePods, removablePods
 }
 
-func averageNodeBasicresources(nodes []*v1.Node, usageClient *requestedUsageClient) api.ResourceThresholds {
+func averageNodeBasicresources(nodes []*v1.Node, usageClient usageClient) api.ResourceThresholds {
 	total := api.ResourceThresholds{}
 	average := api.ResourceThresholds{}
 	numberOfNodes := len(nodes)

pkg/framework/plugins/nodeutilization/usageclients.go

@@ -20,11 +20,20 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/klog/v2"
+	metricsclient "k8s.io/metrics/pkg/client/clientset/versioned"
+	"sigs.k8s.io/descheduler/pkg/descheduler/metricscollector"
 	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
 	"sigs.k8s.io/descheduler/pkg/utils"
 )
 
+type usageClient interface {
+	nodeUtilization(node string) map[v1.ResourceName]*resource.Quantity
+	nodes() []*v1.Node
+	pods(node string) []*v1.Pod
+	capture(nodes []*v1.Node) error
+}
+
 type requestedUsageClient struct {
 	resourceNames         []v1.ResourceName
 	getPodsAssignedToNode podutil.GetPodsAssignedToNodeFunc
@@ -34,6 +43,8 @@ type requestedUsageClient struct {
 	_nodeUtilization map[string]map[v1.ResourceName]*resource.Quantity
 }
 
+var _ usageClient = &requestedUsageClient{}
+
 func newRequestedUsageSnapshot(
 	resourceNames []v1.ResourceName,
 	getPodsAssignedToNode podutil.GetPodsAssignedToNodeFunc,
@@ -59,6 +70,7 @@ func (s *requestedUsageClient) pods(node string) []*v1.Pod {
 func (s *requestedUsageClient) capture(nodes []*v1.Node) error {
 	s._nodeUtilization = make(map[string]map[v1.ResourceName]*resource.Quantity)
 	s._pods = make(map[string][]*v1.Pod)
+  capturedNodes := []*v1.Node{}
 
 	for _, node := range nodes {
 		pods, err := podutil.ListPodsOnANode(node.Name, s.getPodsAssignedToNode, nil)
@@ -78,7 +90,77 @@ func (s *requestedUsageClient) capture(nodes []*v1.Node) error {
 		// store the snapshot of pods from the same (or the closest) node utilization computation
 		s._pods[node.Name] = pods
 		s._nodeUtilization[node.Name] = nodeUsage
+    capturedNodes = append(capturedNodes, node)
 	}
 
+  s._nodes = capturedNodes
+
+	return nil
+}
+
+type actualUsageClient struct {
+	resourceNames         []v1.ResourceName
+	getPodsAssignedToNode podutil.GetPodsAssignedToNodeFunc
+	metricsCollector      *metricscollector.MetricsCollector
+	metricsClientset      metricsclient.Interface
+
+	_nodes           []*v1.Node
+	_pods            map[string][]*v1.Pod
+	_nodeUtilization map[string]map[v1.ResourceName]*resource.Quantity
+}
+
+var _ usageClient = &actualUsageClient{}
+
+func newActualUsageSnapshot(
+	resourceNames []v1.ResourceName,
+	getPodsAssignedToNode podutil.GetPodsAssignedToNodeFunc,
+	metricsCollector *metricscollector.MetricsCollector,
+	metricsClientset metricsclient.Interface,
+) *actualUsageClient {
+	return &actualUsageClient{
+		resourceNames:         resourceNames,
+		getPodsAssignedToNode: getPodsAssignedToNode,
+		metricsCollector:      metricsCollector,
+		metricsClientset:      metricsClientset,
+	}
+}
+
+func (client *actualUsageClient) nodeUtilization(node string) map[v1.ResourceName]*resource.Quantity {
+	return client._nodeUtilization[node]
+}
+
+func (client *actualUsageClient) nodes() []*v1.Node {
+	return client._nodes
+}
+
+func (client *actualUsageClient) pods(node string) []*v1.Pod {
+	return client._pods[node]
+}
+
+func (client *actualUsageClient) capture(nodes []*v1.Node) error {
+	client._nodeUtilization = make(map[string]map[v1.ResourceName]*resource.Quantity)
+	client._pods = make(map[string][]*v1.Pod)
+  capturedNodes := []*v1.Node{}
+
+	for _, node := range nodes {
+		pods, err := podutil.ListPodsOnANode(node.Name, client.getPodsAssignedToNode, nil)
+		if err != nil {
+			klog.V(2).InfoS("Node will not be processed, error accessing its pods", "node", klog.KObj(node), "err", err)
+			continue
+		}
+
+    nodeUsage, err := client.metricsCollector.NodeUsage(node)
+		if err != nil {
+			return err
+		}
+
+		// store the snapshot of pods from the same (or the closest) node utilization computation
+		client._pods[node.Name] = pods
+		client._nodeUtilization[node.Name] = nodeUsage
+    capturedNodes = append(capturedNodes, node)
+	}
+
+  client._nodes = capturedNodes
+
 	return nil
 }

pkg/framework/plugins/nodeutilization/usageclients_test.go

@@ -0,0 +1,136 @@
+/*
+Copyright 2024 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package nodeutilization
+
+import (
+	"context"
+	"fmt"
+	"testing"
+
+	v1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+
+	"k8s.io/client-go/informers"
+	fakeclientset "k8s.io/client-go/kubernetes/fake"
+	"k8s.io/metrics/pkg/apis/metrics/v1beta1"
+	fakemetricsclient "k8s.io/metrics/pkg/client/clientset/versioned/fake"
+	"sigs.k8s.io/descheduler/pkg/descheduler/metricscollector"
+	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
+	"sigs.k8s.io/descheduler/test"
+)
+
+var gvr = schema.GroupVersionResource{Group: "metrics.k8s.io", Version: "v1beta1", Resource: "nodemetricses"}
+
+func updateMetricsAndCheckNodeUtilization(
+	t *testing.T,
+	ctx context.Context,
+	newValue, expectedValue int64,
+	metricsClientset *fakemetricsclient.Clientset,
+	collector *metricscollector.MetricsCollector,
+	usageSnapshot usageClient,
+	nodes []*v1.Node,
+	nodeName string,
+	nodemetrics *v1beta1.NodeMetrics,
+) {
+	t.Logf("Set current node cpu usage to %v", newValue)
+	nodemetrics.Usage[v1.ResourceCPU] = *resource.NewMilliQuantity(newValue, resource.DecimalSI)
+	metricsClientset.Tracker().Update(gvr, nodemetrics, "")
+	err := collector.Collect(ctx)
+	if err != nil {
+		t.Fatalf("failed to capture metrics: %v", err)
+	}
+	err = usageSnapshot.capture(nodes)
+	if err != nil {
+		t.Fatalf("failed to capture a snapshot: %v", err)
+	}
+	nodeUtilization := usageSnapshot.nodeUtilization(nodeName)
+	t.Logf("current node cpu usage: %v\n", nodeUtilization[v1.ResourceCPU].MilliValue())
+	if nodeUtilization[v1.ResourceCPU].MilliValue() != expectedValue {
+		t.Fatalf("cpu node usage expected to be %v, got %v instead", expectedValue, nodeUtilization[v1.ResourceCPU].MilliValue())
+	}
+	pods := usageSnapshot.pods(nodeName)
+	fmt.Printf("pods: %#v\n", pods)
+	if len(pods) != 2 {
+		t.Fatalf("expected 2 pods for node %v, got %v instead", nodeName, len(pods))
+	}
+	capturedNodes := usageSnapshot.nodes()
+	if len(capturedNodes) != 3 {
+		t.Fatalf("expected 3 captured node, got %v instead", len(capturedNodes))
+	}
+}
+
+func TestActualUsageClient(t *testing.T) {
+	n1 := test.BuildTestNode("n1", 2000, 3000, 10, nil)
+	n2 := test.BuildTestNode("n2", 2000, 3000, 10, nil)
+	n3 := test.BuildTestNode("n3", 2000, 3000, 10, nil)
+
+	p1 := test.BuildTestPod("p1", 400, 0, n1.Name, nil)
+	p21 := test.BuildTestPod("p21", 400, 0, n2.Name, nil)
+	p22 := test.BuildTestPod("p22", 400, 0, n2.Name, nil)
+	p3 := test.BuildTestPod("p3", 400, 0, n3.Name, nil)
+
+	nodes := []*v1.Node{n1, n2, n3}
+
+	n1metrics := test.BuildNodeMetrics("n1", 400, 1714978816)
+	n2metrics := test.BuildNodeMetrics("n2", 1400, 1714978816)
+	n3metrics := test.BuildNodeMetrics("n3", 300, 1714978816)
+
+	clientset := fakeclientset.NewSimpleClientset(n1, n2, n3, p1, p21, p22, p3)
+	metricsClientset := fakemetricsclient.NewSimpleClientset(n1metrics, n2metrics, n3metrics)
+
+	ctx := context.TODO()
+
+	resourceNames := []v1.ResourceName{
+		v1.ResourceCPU,
+		v1.ResourceMemory,
+	}
+
+	sharedInformerFactory := informers.NewSharedInformerFactory(clientset, 0)
+	podInformer := sharedInformerFactory.Core().V1().Pods().Informer()
+	podsAssignedToNode, err := podutil.BuildGetPodsAssignedToNodeFunc(podInformer)
+	if err != nil {
+		t.Fatalf("Build get pods assigned to node function error: %v", err)
+	}
+
+	sharedInformerFactory.Start(ctx.Done())
+	sharedInformerFactory.WaitForCacheSync(ctx.Done())
+
+	collector := metricscollector.NewMetricsCollector(clientset, metricsClientset)
+
+	usageSnapshot := newActualUsageSnapshot(
+		resourceNames,
+		podsAssignedToNode,
+		collector,
+		metricsClientset,
+	)
+
+	updateMetricsAndCheckNodeUtilization(t, ctx,
+		1400, 1400,
+		metricsClientset, collector, usageSnapshot, nodes, n2.Name, n2metrics,
+	)
+
+	updateMetricsAndCheckNodeUtilization(t, ctx,
+		500, 1310,
+		metricsClientset, collector, usageSnapshot, nodes, n2.Name, n2metrics,
+	)
+
+	updateMetricsAndCheckNodeUtilization(t, ctx,
+		900, 1269,
+		metricsClientset, collector, usageSnapshot, nodes, n2.Name, n2metrics,
+	)
+}