Merge pull request #43008 from ravisantoshgudimetla/taints_small_changes

Automatic merge from submit-queue (batch tested with PRs 43681, 40423, 43562, 43008, 43381)

Changes for removing deadcode in taint_tolerations

**What this PR does / why we need it**:

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #43007

plugin/pkg/scheduler/algorithm/priorities/metadata.go

@@ -34,13 +34,10 @@ func PriorityMetadata(pod *v1.Pod, nodeNameToInfo map[string]*schedulercache.Nod
 	if pod == nil {
 		return nil
 	}
-	tolerations, err := getTolerationListFromPod(pod)
-	if err != nil {
-		return nil
-	}
+	tolerationsPreferNoSchedule := getAllTolerationPreferNoSchedule(pod.Spec.Tolerations)
 	return &priorityMetadata{
 		nonZeroRequest: getNonZeroRequests(pod),
-		podTolerations: tolerations,
+		podTolerations: tolerationsPreferNoSchedule,
 		affinity:       schedulercache.ReconcileAffinity(pod),
 	}
 }

plugin/pkg/scheduler/algorithm/priorities/taint_toleration.go

@@ -27,56 +27,48 @@ import (
 
 // CountIntolerableTaintsPreferNoSchedule gives the count of intolerable taints of a pod with effect PreferNoSchedule
 func countIntolerableTaintsPreferNoSchedule(taints []v1.Taint, tolerations []v1.Toleration) (intolerableTaints int) {
-	for i := range taints {
-		taint := &taints[i]
+	for _, taint := range taints {
 		// check only on taints that have effect PreferNoSchedule
 		if taint.Effect != v1.TaintEffectPreferNoSchedule {
 			continue
 		}
 
-		if !v1.TolerationsTolerateTaint(tolerations, taint) {
+		if !v1.TolerationsTolerateTaint(tolerations, &taint) {
 			intolerableTaints++
 		}
 	}
 	return
 }
 
-// getAllTolerationEffectPreferNoSchedule gets the list of all Toleration with Effect PreferNoSchedule
+// getAllTolerationEffectPreferNoSchedule gets the list of all Tolerations with Effect PreferNoSchedule or with no effect.
 func getAllTolerationPreferNoSchedule(tolerations []v1.Toleration) (tolerationList []v1.Toleration) {
-	for i := range tolerations {
-		toleration := &tolerations[i]
+	for _, toleration := range tolerations {
+		// Empty effect means all effects which includes PreferNoSchedule, so we need to collect it as well.
 		if len(toleration.Effect) == 0 || toleration.Effect == v1.TaintEffectPreferNoSchedule {
-			tolerationList = append(tolerationList, *toleration)
+			tolerationList = append(tolerationList, toleration)
 		}
 	}
 	return
 }
 
-func getTolerationListFromPod(pod *v1.Pod) ([]v1.Toleration, error) {
-	return getAllTolerationPreferNoSchedule(pod.Spec.Tolerations), nil
-}
-
 // ComputeTaintTolerationPriority prepares the priority list for all the nodes based on the number of intolerable taints on the node
 func ComputeTaintTolerationPriorityMap(pod *v1.Pod, meta interface{}, nodeInfo *schedulercache.NodeInfo) (schedulerapi.HostPriority, error) {
 	node := nodeInfo.Node()
 	if node == nil {
 		return schedulerapi.HostPriority{}, fmt.Errorf("node not found")
 	}
-
-	var tolerationList []v1.Toleration
+	// To hold all the tolerations with Effect PreferNoSchedule
+	var tolerationsPreferNoSchedule []v1.Toleration
 	if priorityMeta, ok := meta.(*priorityMetadata); ok {
-		tolerationList = priorityMeta.podTolerations
+		tolerationsPreferNoSchedule = priorityMeta.podTolerations
+
 	} else {
-		var err error
-		tolerationList, err = getTolerationListFromPod(pod)
-		if err != nil {
-			return schedulerapi.HostPriority{}, err
-		}
+		tolerationsPreferNoSchedule = getAllTolerationPreferNoSchedule(pod.Spec.Tolerations)
 	}
 
 	return schedulerapi.HostPriority{
 		Host:  node.Name,
-		Score: countIntolerableTaintsPreferNoSchedule(node.Spec.Taints, tolerationList),
+		Score: countIntolerableTaintsPreferNoSchedule(node.Spec.Taints, tolerationsPreferNoSchedule),
 	}, nil
 }
 

plugin/pkg/scheduler/algorithm/priorities/taint_toleration_test.go

@@ -204,6 +204,26 @@ func TestTaintAndToleration(t *testing.T) {
 				{Host: "nodeC", Score: 0},
 			},
 		},
+		{
+			test: "Default behaviour No taints and tolerations, lands on node with no taints",
+			//pod without tolerations
+			pod: podWithTolerations([]v1.Toleration{}),
+			nodes: []*v1.Node{
+				//Node without taints
+				nodeWithTaints("nodeA", []v1.Taint{}),
+				nodeWithTaints("nodeB", []v1.Taint{
+					{
+						Key:    "cpu-type",
+						Value:  "arm64",
+						Effect: v1.TaintEffectPreferNoSchedule,
+					},
+				}),
+			},
+			expectedList: []schedulerapi.HostPriority{
+				{Host: "nodeA", Score: 10},
+				{Host: "nodeB", Score: 0},
+			},
+		},
 	}
 	for _, test := range tests {
 		nodeNameToInfo := schedulercache.CreateNodeNameToInfoMap(nil, test.nodes)