ListPodsOnANode: define Options type to pass various options

Options like:
- filter
- included/excluded namespaces
- labels

pkg/descheduler/pod/pods.go

@@ -27,17 +27,33 @@ import (
 	"sigs.k8s.io/descheduler/pkg/utils"
 )
 
+type Options struct {
+	filter func(pod *v1.Pod) bool
+}
+
+// WithFilter sets a pod filter.
+// The filter function should return true if the pod should be returned from ListPodsOnANode
+func WithFilter(filter func(pod *v1.Pod) bool) func(opts *Options) {
+	return func(opts *Options) {
+		opts.filter = filter
+	}
+}
+
 // ListPodsOnANode lists all of the pods on a node
 // It also accepts an optional "filter" function which can be used to further limit the pods that are returned.
 // (Usually this is podEvictor.IsEvictable, in order to only list the evictable pods on a node, but can
 // be used by strategies to extend IsEvictable if there are further restrictions, such as with NodeAffinity).
-// The filter function should return true if the pod should be returned from ListPodsOnANode
 func ListPodsOnANode(
 	ctx context.Context,
 	client clientset.Interface,
 	node *v1.Node,
-	filter func(pod *v1.Pod) bool,
+	opts ...func(opts *Options),
 ) ([]*v1.Pod, error) {
+	options := &Options{}
+	for _, opt := range opts {
+		opt(options)
+	}
+
 	fieldSelector, err := fields.ParseSelector("spec.nodeName=" + node.Name + ",status.phase!=" + string(v1.PodSucceeded) + ",status.phase!=" + string(v1.PodFailed))
 	if err != nil {
 		return []*v1.Pod{}, err
@@ -51,7 +67,7 @@ func ListPodsOnANode(
 
 	pods := make([]*v1.Pod, 0)
 	for i := range podList.Items {
-		if filter != nil && !filter(&podList.Items[i]) {
+		if options.filter != nil && !options.filter(&podList.Items[i]) {
 			continue
 		}
 		pods = append(pods, &podList.Items[i])

pkg/descheduler/pod/pods_test.go

@@ -67,7 +67,7 @@ func TestListPodsOnANode(t *testing.T) {
 			}
 			return true, nil, fmt.Errorf("Failed to list: %v", list)
 		})
-		pods, _ := ListPodsOnANode(context.TODO(), fakeClient, testCase.node, nil)
+		pods, _ := ListPodsOnANode(context.TODO(), fakeClient, testCase.node)
 		if len(pods) != testCase.expectedPodCount {
 			t.Errorf("expected %v pods on node %v, got %+v", testCase.expectedPodCount, testCase.node.Name, len(pods))
 		}

pkg/descheduler/strategies/duplicates.go

@@ -46,7 +46,7 @@ func RemoveDuplicatePods(
 ) {
 	for _, node := range nodes {
 		klog.V(1).Infof("Processing node: %#v", node.Name)
-		pods, err := podutil.ListPodsOnANode(ctx, client, node, podEvictor.IsEvictable)
+		pods, err := podutil.ListPodsOnANode(ctx, client, node, podutil.WithFilter(podEvictor.IsEvictable))
 		if err != nil {
 			klog.Errorf("error listing evictable pods on node %s: %+v", node.Name, err)
 			continue

pkg/descheduler/strategies/lownodeutilization.go

@@ -326,7 +326,7 @@ func sortNodesByUsage(nodes []NodeUsageMap) {
 func createNodePodsMap(ctx context.Context, client clientset.Interface, nodes []*v1.Node) NodePodsMap {
 	npm := NodePodsMap{}
 	for _, node := range nodes {
-		pods, err := podutil.ListPodsOnANode(ctx, client, node, nil)
+		pods, err := podutil.ListPodsOnANode(ctx, client, node)
 		if err != nil {
 			klog.Warningf("node %s will not be processed, error in accessing its pods (%#v)", node.Name, err)
 		} else {

pkg/descheduler/strategies/node_affinity.go

@@ -43,11 +43,11 @@ func RemovePodsViolatingNodeAffinity(ctx context.Context, client clientset.Inter
 			for _, node := range nodes {
 				klog.V(1).Infof("Processing node: %#v\n", node.Name)
 
-				pods, err := podutil.ListPodsOnANode(ctx, client, node, func(pod *v1.Pod) bool {
+				pods, err := podutil.ListPodsOnANode(ctx, client, node, podutil.WithFilter(func(pod *v1.Pod) bool {
 					return podEvictor.IsEvictable(pod) &&
 						!nodeutil.PodFitsCurrentNode(pod, node) &&
 						nodeutil.PodFitsAnyNode(pod, nodes)
-				})
+				}))
 				if err != nil {
 					klog.Errorf("failed to get pods from %v: %v", node.Name, err)
 				}

pkg/descheduler/strategies/node_taint.go

@@ -33,7 +33,7 @@ import (
 func RemovePodsViolatingNodeTaints(ctx context.Context, client clientset.Interface, strategy api.DeschedulerStrategy, nodes []*v1.Node, podEvictor *evictions.PodEvictor) {
 	for _, node := range nodes {
 		klog.V(1).Infof("Processing node: %#v\n", node.Name)
-		pods, err := podutil.ListPodsOnANode(ctx, client, node, podEvictor.IsEvictable)
+		pods, err := podutil.ListPodsOnANode(ctx, client, node, podutil.WithFilter(podEvictor.IsEvictable))
 		if err != nil {
 			//no pods evicted as error encountered retrieving evictable Pods
 			return

pkg/descheduler/strategies/pod_antiaffinity.go

@@ -18,6 +18,7 @@ package strategies
 
 import (
 	"context"
+
 	"sigs.k8s.io/descheduler/pkg/api"
 	"sigs.k8s.io/descheduler/pkg/descheduler/evictions"
 	podutil "sigs.k8s.io/descheduler/pkg/descheduler/pod"
@@ -33,7 +34,7 @@ import (
 func RemovePodsViolatingInterPodAntiAffinity(ctx context.Context, client clientset.Interface, strategy api.DeschedulerStrategy, nodes []*v1.Node, podEvictor *evictions.PodEvictor) {
 	for _, node := range nodes {
 		klog.V(1).Infof("Processing node: %#v\n", node.Name)
-		pods, err := podutil.ListPodsOnANode(ctx, client, node, podEvictor.IsEvictable)
+		pods, err := podutil.ListPodsOnANode(ctx, client, node, podutil.WithFilter(podEvictor.IsEvictable))
 		if err != nil {
 			return
 		}

pkg/descheduler/strategies/pod_lifetime.go

@@ -54,7 +54,7 @@ func PodLifeTime(ctx context.Context, client clientset.Interface, strategy api.D
 }
 
 func listOldPodsOnNode(ctx context.Context, client clientset.Interface, node *v1.Node, maxAge uint, evictor *evictions.PodEvictor) []*v1.Pod {
-	pods, err := podutil.ListPodsOnANode(ctx, client, node, evictor.IsEvictable)
+	pods, err := podutil.ListPodsOnANode(ctx, client, node, podutil.WithFilter(evictor.IsEvictable))
 	if err != nil {
 		return nil
 	}

pkg/descheduler/strategies/toomanyrestarts.go

@@ -38,7 +38,7 @@ func RemovePodsHavingTooManyRestarts(ctx context.Context, client clientset.Inter
 	}
 	for _, node := range nodes {
 		klog.V(1).Infof("Processing node: %s", node.Name)
-		pods, err := podutil.ListPodsOnANode(ctx, client, node, podEvictor.IsEvictable)
+		pods, err := podutil.ListPodsOnANode(ctx, client, node, podutil.WithFilter(podEvictor.IsEvictable))
 		if err != nil {
 			klog.Errorf("Error when list pods at node %s", node.Name)
 			continue

test/e2e/e2e_test.go

@@ -324,7 +324,7 @@ func evictPods(ctx context.Context, t *testing.T, clientSet clientset.Interface,
 			continue
 		}
 		// List all the pods on the current Node
-		podsOnANode, err := podutil.ListPodsOnANode(ctx, clientSet, node, podEvictor.IsEvictable)
+		podsOnANode, err := podutil.ListPodsOnANode(ctx, clientSet, node, podutil.WithFilter(podEvictor.IsEvictable))
 		if err != nil {
 			t.Errorf("Error listing pods on a node %v", err)
 		}
@@ -336,7 +336,7 @@ func evictPods(ctx context.Context, t *testing.T, clientSet clientset.Interface,
 	}
 	t.Log("Eviction of pods starting")
 	startEndToEndForLowNodeUtilization(ctx, clientSet, nodeInformer, podEvictor)
-	podsOnleastUtilizedNode, err := podutil.ListPodsOnANode(ctx, clientSet, leastLoadedNode, podEvictor.IsEvictable)
+	podsOnleastUtilizedNode, err := podutil.ListPodsOnANode(ctx, clientSet, leastLoadedNode, podutil.WithFilter(podEvictor.IsEvictable))
 	if err != nil {
 		t.Errorf("Error listing pods on a node %v", err)
 	}