De-duping node "update enqueuing"/sync predicates

staging/src/k8s.io/cloud-provider/controllers/service/controller.go

@@ -175,7 +175,7 @@ func New(
 					return
 				}
 
-				if !shouldSyncNode(oldNode, curNode) {
+				if !shouldSyncUpdatedNode(oldNode, curNode) {
 					return
 				}
 
@@ -254,7 +254,7 @@ func (c *Controller) Run(ctx context.Context, workers int) {
 func (c *Controller) triggerNodeSync() {
 	c.nodeSyncLock.Lock()
 	defer c.nodeSyncLock.Unlock()
-	newHosts, err := listWithPredicate(c.nodeLister, c.getNodeConditionPredicate())
+	newHosts, err := listWithPredicates(c.nodeLister, allNodePredicates...)
 	if err != nil {
 		runtime.HandleError(fmt.Errorf("Failed to retrieve current set of nodes from node lister: %v", err))
 		// if node list cannot be retrieve, trigger full node sync to be safe.
@@ -450,7 +450,7 @@ func (c *Controller) syncLoadBalancerIfNeeded(ctx context.Context, service *v1.S
 }
 
 func (c *Controller) ensureLoadBalancer(ctx context.Context, service *v1.Service) (*v1.LoadBalancerStatus, error) {
-	nodes, err := listWithPredicate(c.nodeLister, c.getNodeConditionPredicate())
+	nodes, err := listWithPredicates(c.nodeLister, allNodePredicates...)
 	if err != nil {
 		return nil, err
 	}
@@ -679,58 +679,8 @@ func nodeSlicesEqualForLB(x, y []*v1.Node) bool {
 	return nodeNames(x).Equal(nodeNames(y))
 }
 
-func (c *Controller) getNodeConditionPredicate() NodeConditionPredicate {
-	return func(node *v1.Node) bool {
-		if _, hasExcludeBalancerLabel := node.Labels[v1.LabelNodeExcludeBalancers]; hasExcludeBalancerLabel {
-			return false
-		}
-
-		// Remove nodes that are about to be deleted by the cluster autoscaler.
-		for _, taint := range node.Spec.Taints {
-			if taint.Key == ToBeDeletedTaint {
-				klog.V(4).Infof("Ignoring node %v with autoscaler taint %+v", node.Name, taint)
-				return false
-			}
-		}
-
-		// If we have no info, don't accept
-		if len(node.Status.Conditions) == 0 {
-			return false
-		}
-		for _, cond := range node.Status.Conditions {
-			// We consider the node for load balancing only when its NodeReady condition status
-			// is ConditionTrue
-			if cond.Type == v1.NodeReady && cond.Status != v1.ConditionTrue {
-				klog.V(4).Infof("Ignoring node %v with %v condition status %v", node.Name, cond.Type, cond.Status)
-				return false
-			}
-		}
-		return true
-	}
-}
-
-func shouldSyncNode(oldNode, newNode *v1.Node) bool {
-	if oldNode.Spec.Unschedulable != newNode.Spec.Unschedulable {
-		return true
-	}
-
-	if !reflect.DeepEqual(oldNode.Labels, newNode.Labels) {
-		return true
-	}
-
-	return nodeReadyConditionStatus(oldNode) != nodeReadyConditionStatus(newNode)
-}
-
-func nodeReadyConditionStatus(node *v1.Node) v1.ConditionStatus {
-	for _, condition := range node.Status.Conditions {
-		if condition.Type != v1.NodeReady {
-			continue
-		}
-
-		return condition.Status
-	}
-
-	return ""
+func shouldSyncUpdatedNode(oldNode, newNode *v1.Node) bool {
+	return respectsPredicates(oldNode, allNodePredicates...) != respectsPredicates(newNode, allNodePredicates...)
 }
 
 // nodeSyncInternal handles updating the hosts pointed to by all load
@@ -778,7 +728,7 @@ func (c *Controller) nodeSyncService(svc *v1.Service) bool {
 		return false
 	}
 	klog.V(4).Infof("nodeSyncService started for service %s/%s", svc.Namespace, svc.Name)
-	hosts, err := listWithPredicate(c.nodeLister, c.getNodeConditionPredicate())
+	hosts, err := listWithPredicates(c.nodeLister, allNodePredicates...)
 	if err != nil {
 		runtime.HandleError(fmt.Errorf("failed to retrieve node list: %v", err))
 		return true
@@ -987,19 +937,70 @@ func (c *Controller) patchStatus(service *v1.Service, previousStatus, newStatus
 // some set of criteria defined by the function.
 type NodeConditionPredicate func(node *v1.Node) bool
 
-// listWithPredicate gets nodes that matches predicate function.
-func listWithPredicate(nodeLister corelisters.NodeLister, predicate NodeConditionPredicate) ([]*v1.Node, error) {
+var (
+	allNodePredicates []NodeConditionPredicate = []NodeConditionPredicate{
+		nodeIncludedPredicate,
+		nodeSchedulablePredicate,
+		nodeUnTaintedPredicate,
+		nodeReadyPredicate,
+	}
+)
+
+// We consider the node for load balancing only when the node is not labelled for exclusion.
+func nodeIncludedPredicate(node *v1.Node) bool {
+	_, hasExcludeBalancerLabel := node.Labels[v1.LabelNodeExcludeBalancers]
+	return !hasExcludeBalancerLabel
+}
+
+// We consider the node for load balancing only when the node is schedulable.
+func nodeSchedulablePredicate(node *v1.Node) bool {
+	return !node.Spec.Unschedulable
+}
+
+// We consider the node for load balancing only when its not tainted for deletion by the cluster autoscaler.
+func nodeUnTaintedPredicate(node *v1.Node) bool {
+	for _, taint := range node.Spec.Taints {
+		if taint.Key == ToBeDeletedTaint {
+			return false
+		}
+	}
+	return true
+}
+
+// We consider the node for load balancing only when its NodeReady condition status is ConditionTrue
+func nodeReadyPredicate(node *v1.Node) bool {
+	for _, cond := range node.Status.Conditions {
+		if cond.Type == v1.NodeReady {
+			return cond.Status == v1.ConditionTrue
+		}
+	}
+	return false
+}
+
+// listWithPredicate gets nodes that matches all predicate functions.
+func listWithPredicates(nodeLister corelisters.NodeLister, predicates ...NodeConditionPredicate) ([]*v1.Node, error) {
 	nodes, err := nodeLister.List(labels.Everything())
 	if err != nil {
 		return nil, err
 	}
+	return filterWithPredicates(nodes, predicates...), nil
+}
 
+func filterWithPredicates(nodes []*v1.Node, predicates ...NodeConditionPredicate) []*v1.Node {
 	var filtered []*v1.Node
 	for i := range nodes {
-		if predicate(nodes[i]) {
+		if respectsPredicates(nodes[i], predicates...) {
 			filtered = append(filtered, nodes[i])
 		}
 	}
-
-	return filtered, nil
+	return filtered
+}
+
+func respectsPredicates(node *v1.Node, predicates ...NodeConditionPredicate) bool {
+	for _, p := range predicates {
+		if !p(node) {
+			return false
+		}
+	}
+	return true
 }