controller: factor out pod node name indexer helper function

Signed-off-by: xigang <[email protected]>

Author: xigang

pkg/controller/controller_utils.go

@@ -83,6 +83,9 @@ const (
 	// The number of batches is given by:
 	//      1+floor(log_2(ceil(N/SlowStartInitialBatchSize)))
 	SlowStartInitialBatchSize = 1
+
+	// PodNodeNameKeyIndex is the name of the index used by PodInformer to index pods by their node name.
+	PodNodeNameKeyIndex = "spec.nodeName"
 )
 
 var UpdateTaintBackoff = wait.Backoff{
@@ -1051,6 +1054,28 @@ func FilterReplicaSets(RSes []*apps.ReplicaSet, filterFn filterRS) []*apps.Repli
 	return filtered
 }
 
+// AddPodNodeNameIndexer adds an indexer for Pod's nodeName to the given PodInformer.
+// This indexer is used to efficiently look up pods by their node name.
+func AddPodNodeNameIndexer(podInformer cache.SharedIndexInformer) error {
+	if _, exists := podInformer.GetIndexer().GetIndexers()[PodNodeNameKeyIndex]; exists {
+		// indexer already exists, do nothing
+		return nil
+	}
+
+	return podInformer.AddIndexers(cache.Indexers{
+		PodNodeNameKeyIndex: func(obj interface{}) ([]string, error) {
+			pod, ok := obj.(*v1.Pod)
+			if !ok {
+				return []string{}, nil
+			}
+			if len(pod.Spec.NodeName) == 0 {
+				return []string{}, nil
+			}
+			return []string{pod.Spec.NodeName}, nil
+		},
+	})
+}
+
 // PodKey returns a key unique to the given pod within a cluster.
 // It's used so we consistently use the same key scheme in this module.
 // It does exactly what cache.MetaNamespaceKeyFunc would have done

pkg/controller/nodelifecycle/node_lifecycle_controller.go

@@ -125,8 +125,7 @@ const (
 
 const (
 	// The amount of time the nodecontroller should sleep between retrying node health updates
-	retrySleepTime   = 20 * time.Millisecond
-	nodeNameKeyIndex = "spec.nodeName"
+	retrySleepTime = 20 * time.Millisecond
 	// podUpdateWorkerSizes assumes that in most cases pod will be handled by monitorNodeHealth pass.
 	// Pod update workers will only handle lagging cache pods. 4 workers should be enough.
 	podUpdateWorkerSize = 4
@@ -388,22 +387,10 @@ func NewNodeLifecycleController(
 		},
 	})
 	nc.podInformerSynced = podInformer.Informer().HasSynced
-	podInformer.Informer().AddIndexers(cache.Indexers{
-		nodeNameKeyIndex: func(obj interface{}) ([]string, error) {
-			pod, ok := obj.(*v1.Pod)
-			if !ok {
-				return []string{}, nil
-			}
-			if len(pod.Spec.NodeName) == 0 {
-				return []string{}, nil
-			}
-			return []string{pod.Spec.NodeName}, nil
-		},
-	})
-
+	controller.AddPodNodeNameIndexer(podInformer.Informer())
 	podIndexer := podInformer.Informer().GetIndexer()
 	nc.getPodsAssignedToNode = func(nodeName string) ([]*v1.Pod, error) {
-		objs, err := podIndexer.ByIndex(nodeNameKeyIndex, nodeName)
+		objs, err := podIndexer.ByIndex(controller.PodNodeNameKeyIndex, nodeName)
 		if err != nil {
 			return nil, err
 		}