min replicas - use informer indexer for pod owner ref uid

Signed-off-by: Amir Alavi <amiralavi7@gmail.com>

README.md

@@ -142,7 +142,7 @@ The Default Evictor Plugin is used by default for filtering pods before processi
 |`labelSelector`|`metav1.LabelSelector`||(see [label filtering](#label-filtering))|
 |`priorityThreshold`|`priorityThreshold`||(see [priority filtering](#priority-filtering))|
 |`nodeFit`|`bool`|`false`|(see [node fit filtering](#node-fit-filtering))|
-|`minReplicas`|`uint`|`0`| ignore eviction of pods where owner (e.g. Deployment) replicas is below this threshold |
+|`minReplicas`|`uint`|`0`| ignore eviction of pods where owner (e.g. `ReplicaSet`) replicas is below this threshold |
 
 ### Example policy
 

pkg/descheduler/pod/pods.go

@@ -143,21 +143,25 @@ func BuildGetPodsAssignedToNodeFunc(podInformer cache.SharedIndexInformer) (GetP
 		if err != nil {
 			return nil, err
 		}
-		pods := make([]*v1.Pod, 0, len(objs))
-		for _, obj := range objs {
-			pod, ok := obj.(*v1.Pod)
-			if !ok {
-				continue
-			}
-			if filter(pod) {
-				pods = append(pods, pod)
-			}
-		}
-		return pods, nil
+		return ConvertToPods(objs, filter), nil
 	}
 	return getPodsAssignedToNode, nil
 }
 
+func ConvertToPods(objs []interface{}, filter FilterFunc) []*v1.Pod {
+	pods := make([]*v1.Pod, 0, len(objs))
+	for _, obj := range objs {
+		pod, ok := obj.(*v1.Pod)
+		if !ok {
+			continue
+		}
+		if filter == nil || filter(pod) {
+			pods = append(pods, pod)
+		}
+	}
+	return pods
+}
+
 // ListPodsOnNodes returns all pods on given nodes.
 func ListPodsOnNodes(nodes []*v1.Node, getPodsAssignedToNode GetPodsAssignedToNodeFunc, filter FilterFunc) ([]*v1.Pod, error) {
 	pods := make([]*v1.Pod, 0)
@@ -216,6 +220,14 @@ func OwnerRef(pod *v1.Pod) []metav1.OwnerReference {
 	return pod.ObjectMeta.GetOwnerReferences()
 }
 
+func OwnerRefUIDs(pod *v1.Pod) []string {
+	var ownerRefUIDs []string
+	for _, ownerRef := range OwnerRef(pod) {
+		ownerRefUIDs = append(ownerRefUIDs, string(ownerRef.UID))
+	}
+	return ownerRefUIDs
+}
+
 func IsBestEffortPod(pod *v1.Pod) bool {
 	return utils.GetPodQOS(pod) == v1.PodQOSBestEffort
 }

pkg/framework/plugins/defaultevictor/defaultevictor.go

@@ -16,13 +16,15 @@ package defaultevictor
 import (
 	// "context"
 	"context"
+	"errors"
 	"fmt"
 
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	"k8s.io/apimachinery/pkg/runtime"
-	"k8s.io/apimachinery/pkg/util/errors"
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/client-go/tools/cache"
 	"k8s.io/klog/v2"
 	nodeutil "sigs.k8s.io/descheduler/pkg/descheduler/node"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
@@ -144,16 +146,33 @@ func New(args runtime.Object, handle frameworktypes.Handle) (frameworktypes.Plug
 	}
 
 	if defaultEvictorArgs.MinReplicas > 1 {
-		podLister := handle.SharedInformerFactory().Core().V1().Pods().Lister()
+		indexName := "metadata.ownerReferences"
+		indexer, err := getPodIndexerByOwnerRefs(indexName, handle)
+		if err != nil {
+			return nil, err
+		}
 		ev.constraints = append(ev.constraints, func(pod *v1.Pod) error {
-			pods, err := podLister.Pods(pod.Namespace).List(labels.Everything())
+			if len(pod.OwnerReferences) == 0 {
+				return nil
+			}
+
+			if len(pod.OwnerReferences) > 1 {
+				klog.V(5).InfoS("pod has %d owner references which is not supported for MinReplicas check", len(pod.OwnerReferences))
+				return nil
+			}
+
+			ownerRef := pod.OwnerReferences[0]
+			objs, err := indexer.ByIndex(indexName, string(ownerRef.UID))
 			if err != nil {
 				return fmt.Errorf("unable to list pods for minReplicas filter in the policy parameter")
 			}
+
+			pods := podutil.ConvertToPods(objs, nil)
 			ownerReplicas := podutil.GetOwnerReplicasCount(pods, pod)
 			if ownerReplicas < defaultEvictorArgs.MinReplicas {
 				return fmt.Errorf("owner has %d replicas which is less than minReplicas of %d", ownerReplicas, defaultEvictorArgs.MinReplicas)
 			}
+
 			return nil
 		})
 	}
@@ -214,9 +233,28 @@ func (d *DefaultEvictor) Filter(pod *v1.Pod) bool {
 	}
 
 	if len(checkErrs) > 0 {
-		klog.V(4).InfoS("Pod fails the following checks", "pod", klog.KObj(pod), "checks", errors.NewAggregate(checkErrs).Error())
+		klog.V(4).InfoS("Pod fails the following checks", "pod", klog.KObj(pod), "checks", utilerrors.NewAggregate(checkErrs).Error())
 		return false
 	}
 
 	return true
 }
+
+func getPodIndexerByOwnerRefs(indexName string, handle frameworktypes.Handle) (cache.Indexer, error) {
+	podInformer := handle.SharedInformerFactory().Core().V1().Pods().Informer()
+	if err := podInformer.AddIndexers(cache.Indexers{
+		indexName: func(obj interface{}) ([]string, error) {
+			pod, ok := obj.(*v1.Pod)
+			if !ok {
+				return []string{}, errors.New("unexpected object")
+			}
+
+			return podutil.OwnerRefUIDs(pod), nil
+		},
+	}); err != nil {
+		return nil, err
+	}
+
+	indexer := podInformer.GetIndexer()
+	return indexer, nil
+}

pkg/framework/plugins/defaultevictor/defaultevictor_test.go

@@ -20,6 +20,7 @@ import (
 	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/resource"
 	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/util/uuid"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes/fake"
 	"sigs.k8s.io/descheduler/pkg/api"
@@ -363,6 +364,8 @@ func TestDefaultEvictorFilter(t *testing.T) {
 	nodeTaintKey := "hardware"
 	nodeTaintValue := "gpu"
 
+	ownerRefUUID := uuid.NewUUID()
+
 	type testCase struct {
 		description             string
 		pods                    []*v1.Pod
@@ -710,9 +713,11 @@ func TestDefaultEvictorFilter(t *testing.T) {
 			pods: []*v1.Pod{
 				test.BuildTestPod("p1", 1, 1, n1.Name, func(pod *v1.Pod) {
 					pod.ObjectMeta.OwnerReferences = test.GetNormalPodOwnerRefList()
+					pod.ObjectMeta.OwnerReferences[0].UID = ownerRefUUID
 				}),
 				test.BuildTestPod("p2", 1, 1, n1.Name, func(pod *v1.Pod) {
 					pod.ObjectMeta.OwnerReferences = test.GetNormalPodOwnerRefList()
+					pod.ObjectMeta.OwnerReferences[0].UID = ownerRefUUID
 				}),
 			},
 			minReplicas: 2,
@@ -722,13 +727,28 @@ func TestDefaultEvictorFilter(t *testing.T) {
 			pods: []*v1.Pod{
 				test.BuildTestPod("p1", 1, 1, n1.Name, func(pod *v1.Pod) {
 					pod.ObjectMeta.OwnerReferences = test.GetNormalPodOwnerRefList()
+					pod.ObjectMeta.OwnerReferences[0].UID = ownerRefUUID
 				}),
 				test.BuildTestPod("p2", 1, 1, n1.Name, func(pod *v1.Pod) {
 					pod.ObjectMeta.OwnerReferences = test.GetNormalPodOwnerRefList()
+					pod.ObjectMeta.OwnerReferences[0].UID = ownerRefUUID
 				}),
 			},
 			minReplicas: 3,
 			result:      false,
+		}, {
+			description: "minReplicas of 2, multiple owners, no eviction",
+			pods: []*v1.Pod{
+				test.BuildTestPod("p1", 1, 1, n1.Name, func(pod *v1.Pod) {
+					pod.ObjectMeta.OwnerReferences = append(test.GetNormalPodOwnerRefList(), test.GetNormalPodOwnerRefList()...)
+					pod.ObjectMeta.OwnerReferences[0].UID = ownerRefUUID
+				}),
+				test.BuildTestPod("p2", 1, 1, n1.Name, func(pod *v1.Pod) {
+					pod.ObjectMeta.OwnerReferences = test.GetNormalPodOwnerRefList()
+				}),
+			},
+			minReplicas: 2,
+			result:      true,
 		},
 	}