Pass the strategy name into evictor through context

pkg/descheduler/descheduler.go

@@ -302,7 +302,7 @@ func RunDeschedulerStrategies(ctx context.Context, rs *options.DeschedulerServer
 						continue
 					}
 					evictorFilter := evictions.NewEvictorFilter(nodes, getPodsAssignedToNode, evictLocalStoragePods, evictSystemCriticalPods, ignorePvcPods, evictBarePods, evictions.WithNodeFit(nodeFit), evictions.WithPriorityThreshold(thresholdPriority))
-					f(ctx, rs.Client, strategy, nodes, podEvictor, evictorFilter, getPodsAssignedToNode)
+					f(context.WithValue(ctx, "strategyName", string(name)), rs.Client, strategy, nodes, podEvictor, evictorFilter, getPodsAssignedToNode)
 				}
 			} else {
 				klog.ErrorS(fmt.Errorf("unknown strategy name"), "skipping strategy", "strategy", name)

pkg/descheduler/evictions/evictions.go

@@ -19,7 +19,6 @@ package evictions
 import (
 	"context"
 	"fmt"
-	"strings"
 
 	v1 "k8s.io/api/core/v1"
 	policy "k8s.io/api/policy/v1beta1"
@@ -106,11 +105,17 @@ func (pe *PodEvictor) TotalEvicted() uint {
 // EvictPod returns non-nil error only when evicting a pod on a node is not
 // possible (due to maxPodsToEvictPerNode constraint). Success is true when the pod
 // is evicted on the server side.
-func (pe *PodEvictor) EvictPod(ctx context.Context, pod *v1.Pod, node *v1.Node, strategy string, reasons ...string) (bool, error) {
-	reason := strategy
-	if len(reasons) > 0 {
-		reason += " (" + strings.Join(reasons, ", ") + ")"
+// eviction reason can be set through the ctx's evictionReason:STRING pair
+func (pe *PodEvictor) EvictPod(ctx context.Context, pod *v1.Pod, node *v1.Node) (bool, error) {
+	strategy := ""
+	if ctx.Value("strategyName") != nil {
+		strategy = ctx.Value("strategyName").(string)
 	}
+	reason := ""
+	if ctx.Value("evictionReason") != nil {
+		reason = ctx.Value("evictionReason").(string)
+	}
+
 	if pe.maxPodsToEvictPerNode != nil && pe.nodepodCount[node]+1 > *pe.maxPodsToEvictPerNode {
 		if pe.metricsEnabled {
 			metrics.PodsEvicted.With(map[string]string{"result": "maximum number of pods per node reached", "strategy": strategy, "namespace": pod.Namespace, "node": node.Name}).Inc()

pkg/descheduler/strategies/duplicates.go

@@ -199,7 +199,7 @@ func RemoveDuplicatePods(
 				// It's assumed all duplicated pods are in the same priority class
 				// TODO(jchaloup): check if the pod has a different node to lend to
 				for _, pod := range pods[upperAvg-1:] {
-					if _, err := podEvictor.EvictPod(ctx, pod, nodeMap[nodeName], "RemoveDuplicatePods"); err != nil {
+					if _, err := podEvictor.EvictPod(ctx, pod, nodeMap[nodeName]); err != nil {
 						klog.ErrorS(err, "Error evicting pod", "pod", klog.KObj(pod))
 						break
 					}

pkg/descheduler/strategies/failedpods.go

@@ -75,7 +75,7 @@ func RemoveFailedPods(
 				continue
 			}
 
-			if _, err = podEvictor.EvictPod(ctx, pods[i], node, "FailedPod"); err != nil {
+			if _, err = podEvictor.EvictPod(ctx, pods[i], node); err != nil {
 				klog.ErrorS(err, "Error evicting pod", "pod", klog.KObj(pod))
 				break
 			}

pkg/descheduler/strategies/node_affinity.go

@@ -93,7 +93,7 @@ func RemovePodsViolatingNodeAffinity(ctx context.Context, client clientset.Inter
 				for _, pod := range pods {
 					if pod.Spec.Affinity != nil && pod.Spec.Affinity.NodeAffinity != nil && pod.Spec.Affinity.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution != nil {
 						klog.V(1).InfoS("Evicting pod", "pod", klog.KObj(pod))
-						if _, err := podEvictor.EvictPod(ctx, pod, node, "NodeAffinity"); err != nil {
+						if _, err := podEvictor.EvictPod(ctx, pod, node); err != nil {
 							klog.ErrorS(err, "Error evicting pod")
 							break
 						}

pkg/descheduler/strategies/node_taint.go

@@ -106,7 +106,7 @@ func RemovePodsViolatingNodeTaints(ctx context.Context, client clientset.Interfa
 				taintFilterFnc,
 			) {
 				klog.V(2).InfoS("Not all taints with NoSchedule effect are tolerated after update for pod on node", "pod", klog.KObj(pods[i]), "node", klog.KObj(node))
-				if _, err := podEvictor.EvictPod(ctx, pods[i], node, "NodeTaint"); err != nil {
+				if _, err := podEvictor.EvictPod(ctx, pods[i], node); err != nil {
 					klog.ErrorS(err, "Error evicting pod")
 					break
 				}

pkg/descheduler/strategies/nodeutilization/nodeutilization.go

@@ -313,7 +313,7 @@ func evictPods(
 				continue
 			}
 
-			success, err := podEvictor.EvictPod(ctx, pod, nodeInfo.node, strategy)
+			success, err := podEvictor.EvictPod(ctx, pod, nodeInfo.node)
 			if err != nil {
 				klog.ErrorS(err, "Error evicting pod", "pod", klog.KObj(pod))
 				break

pkg/descheduler/strategies/pod_antiaffinity.go

@@ -86,7 +86,7 @@ func RemovePodsViolatingInterPodAntiAffinity(ctx context.Context, client clients
 		totalPods := len(pods)
 		for i := 0; i < totalPods; i++ {
 			if checkPodsWithAntiAffinityExist(pods[i], pods) && evictorFilter.Filter(pods[i]) {
-				success, err := podEvictor.EvictPod(ctx, pods[i], node, "InterPodAntiAffinity")
+				success, err := podEvictor.EvictPod(ctx, pods[i], node)
 				if err != nil {
 					klog.ErrorS(err, "Error evicting pod")
 					break

pkg/descheduler/strategies/pod_lifetime.go

@@ -107,7 +107,7 @@ func PodLifeTime(ctx context.Context, client clientset.Interface, strategy api.D
 	podutil.SortPodsBasedOnAge(podsToEvict)
 
 	for _, pod := range podsToEvict {
-		success, err := podEvictor.EvictPod(ctx, pod, nodeMap[pod.Spec.NodeName], "PodLifeTime")
+		success, err := podEvictor.EvictPod(ctx, pod, nodeMap[pod.Spec.NodeName])
 		if success {
 			klog.V(1).InfoS("Evicted pod because it exceeded its lifetime", "pod", klog.KObj(pod), "maxPodLifeTime", *strategy.Params.PodLifeTime.MaxPodLifeTimeSeconds)
 		}

pkg/descheduler/strategies/toomanyrestarts.go

@@ -89,7 +89,7 @@ func RemovePodsHavingTooManyRestarts(ctx context.Context, client clientset.Inter
 			} else if restarts < strategy.Params.PodsHavingTooManyRestarts.PodRestartThreshold {
 				continue
 			}
-			if _, err := podEvictor.EvictPod(ctx, pods[i], node, "TooManyRestarts"); err != nil {
+			if _, err := podEvictor.EvictPod(ctx, pods[i], node); err != nil {
 				klog.ErrorS(err, "Error evicting pod", "pod", klog.KObj(pod))
 				break
 			}

pkg/descheduler/strategies/topologyspreadconstraint.go

@@ -187,7 +187,7 @@ func RemovePodsViolatingTopologySpreadConstraint(
 		if !isEvictable(pod) {
 			continue
 		}
-		if _, err := podEvictor.EvictPod(ctx, pod, nodeMap[pod.Spec.NodeName], "PodTopologySpread"); err != nil {
+		if _, err := podEvictor.EvictPod(ctx, pod, nodeMap[pod.Spec.NodeName]); err != nil {
 			klog.ErrorS(err, "Error evicting pod", "pod", klog.KObj(pod))
 			break
 		}