Merge pull request #30807 from caesarxuchao/change_pod_lister_api

contrib/mesos/pkg/service/endpoints_controller.go

@@ -292,8 +292,9 @@ func (e *endpointController) syncService(key string) {
 
 	subsets := []api.EndpointSubset{}
 	containerPortAnnotations := map[string]string{} // by <HostIP>:<Port>
-	for i := range pods.Items {
-		pod := &pods.Items[i]
+	for i := range pods {
+		// TODO: Do we need to copy here?
+		pod := &(*pods[i])
 
 		for i := range service.Spec.Ports {
 			servicePort := &service.Spec.Ports[i]

pkg/client/cache/listers.go

@@ -49,13 +49,9 @@ type StoreToPodLister struct {
 // Please note that selector is filtering among the pods that have gotten into
 // the store; there may have been some filtering that already happened before
 // that.
-//
-// TODO: converge on the interface in pkg/client.
+// We explicitly don't return api.PodList, to avoid expensive allocations, which
+// in most cases are unnecessary.
 func (s *StoreToPodLister) List(selector labels.Selector) (pods []*api.Pod, err error) {
-	// TODO: it'd be great to just call
-	// s.Pods(api.NamespaceAll).List(selector), however then we'd have to
-	// remake the list.Items as a []*api.Pod. So leave this separate for
-	// now.
 	for _, m := range s.Indexer.List() {
 		pod := m.(*api.Pod)
 		if selector.Matches(labels.Set(pod.Labels)) {
@@ -78,14 +74,14 @@ type storePodsNamespacer struct {
 // Please note that selector is filtering among the pods that have gotten into
 // the store; there may have been some filtering that already happened before
 // that.
-func (s storePodsNamespacer) List(selector labels.Selector) (api.PodList, error) {
-	pods := api.PodList{}
-
+// We explicitly don't return api.PodList, to avoid expensive allocations, which
+// in most cases are unnecessary.
+func (s storePodsNamespacer) List(selector labels.Selector) (pods []*api.Pod, err error) {
 	if s.namespace == api.NamespaceAll {
 		for _, m := range s.indexer.List() {
 			pod := m.(*api.Pod)
 			if selector.Matches(labels.Set(pod.Labels)) {
-				pods.Items = append(pods.Items, *pod)
+				pods = append(pods, pod)
 			}
 		}
 		return pods, nil
@@ -99,7 +95,7 @@ func (s storePodsNamespacer) List(selector labels.Selector) (api.PodList, error)
 		for _, m := range s.indexer.List() {
 			pod := m.(*api.Pod)
 			if s.namespace == pod.Namespace && selector.Matches(labels.Set(pod.Labels)) {
-				pods.Items = append(pods.Items, *pod)
+				pods = append(pods, pod)
 			}
 		}
 		return pods, nil
@@ -107,7 +103,7 @@ func (s storePodsNamespacer) List(selector labels.Selector) (api.PodList, error)
 	for _, m := range items {
 		pod := m.(*api.Pod)
 		if selector.Matches(labels.Set(pod.Labels)) {
-			pods.Items = append(pods.Items, *pod)
+			pods = append(pods, pod)
 		}
 	}
 	return pods, nil

pkg/client/cache/listers_test.go

@@ -718,9 +718,9 @@ func TestStoreToPodLister(t *testing.T) {
 		defaultPods, err := spl.Pods(api.NamespaceDefault).List(labels.Set{}.AsSelector())
 		if err != nil {
 			t.Errorf("Unexpected error: %v", err)
-		} else if e, a := 1, len(defaultPods.Items); e != a {
+		} else if e, a := 1, len(defaultPods); e != a {
 			t.Errorf("Expected %v, got %v", e, a)
-		} else if e, a := "quux", defaultPods.Items[0].Name; e != a {
+		} else if e, a := "quux", defaultPods[0].Name; e != a {
 			t.Errorf("Expected %v, got %v", e, a)
 		}
 

pkg/controller/controller_ref_manager.go

@@ -53,7 +53,7 @@ func NewPodControllerRefManager(
 // controllerRef pointing to other object are ignored) 3. controlledDoesNotMatch
 // are the pods that have a controllerRef pointing to the controller, but their
 // labels no longer match the selector.
-func (m *PodControllerRefManager) Classify(pods []api.Pod) (
+func (m *PodControllerRefManager) Classify(pods []*api.Pod) (
 	matchesAndControlled []*api.Pod,
 	matchesNeedsController []*api.Pod,
 	controlledDoesNotMatch []*api.Pod) {
@@ -69,9 +69,9 @@ func (m *PodControllerRefManager) Classify(pods []api.Pod) (
 			if controllerRef.UID == m.controllerObject.UID {
 				// already controlled
 				if m.controllerSelector.Matches(labels.Set(pod.Labels)) {
-					matchesAndControlled = append(matchesAndControlled, &pod)
+					matchesAndControlled = append(matchesAndControlled, pod)
 				} else {
-					controlledDoesNotMatch = append(controlledDoesNotMatch, &pod)
+					controlledDoesNotMatch = append(controlledDoesNotMatch, pod)
 				}
 			} else {
 				// ignoring the pod controlled by other controller
@@ -83,7 +83,7 @@ func (m *PodControllerRefManager) Classify(pods []api.Pod) (
 			if !m.controllerSelector.Matches(labels.Set(pod.Labels)) {
 				continue
 			}
-			matchesNeedsController = append(matchesNeedsController, &pod)
+			matchesNeedsController = append(matchesNeedsController, pod)
 		}
 	}
 	return matchesAndControlled, matchesNeedsController, controlledDoesNotMatch

pkg/controller/controller_utils.go

@@ -683,12 +683,11 @@ func maxContainerRestarts(pod *api.Pod) int {
 }
 
 // FilterActivePods returns pods that have not terminated.
-func FilterActivePods(pods []api.Pod) []*api.Pod {
+func FilterActivePods(pods []*api.Pod) []*api.Pod {
 	var result []*api.Pod
-	for i := range pods {
-		p := pods[i]
+	for _, p := range pods {
 		if IsPodActive(p) {
-			result = append(result, &p)
+			result = append(result, p)
 		} else {
 			glog.V(4).Infof("Ignoring inactive pod %v/%v in state %v, deletion time %v",
 				p.Namespace, p.Name, p.Status.Phase, p.DeletionTimestamp)
@@ -697,7 +696,7 @@ func FilterActivePods(pods []api.Pod) []*api.Pod {
 	return result
 }
 
-func IsPodActive(p api.Pod) bool {
+func IsPodActive(p *api.Pod) bool {
 	return api.PodSucceeded != p.Status.Phase &&
 		api.PodFailed != p.Status.Phase &&
 		p.DeletionTimestamp == nil

pkg/controller/controller_utils_test.go

@@ -287,7 +287,11 @@ func TestActivePodFiltering(t *testing.T) {
 		expectedNames.Insert(pod.Name)
 	}
 
-	got := FilterActivePods(podList.Items)
+	var podPointers []*api.Pod
+	for i := range podList.Items {
+		podPointers = append(podPointers, &podList.Items[i])
+	}
+	got := FilterActivePods(podPointers)
 	gotNames := sets.NewString()
 	for _, pod := range got {
 		gotNames.Insert(pod.Name)

pkg/controller/daemon/daemoncontroller.go

@@ -458,9 +458,11 @@ func (dsc *DaemonSetsController) getNodesToDaemonPods(ds *extensions.DaemonSet)
 	if err != nil {
 		return nodeToDaemonPods, err
 	}
-	for i := range daemonPods.Items {
-		nodeName := daemonPods.Items[i].Spec.NodeName
-		nodeToDaemonPods[nodeName] = append(nodeToDaemonPods[nodeName], &daemonPods.Items[i])
+	for i := range daemonPods {
+		// TODO: Do we need to copy here?
+		daemonPod := &(*daemonPods[i])
+		nodeName := daemonPod.Spec.NodeName
+		nodeToDaemonPods[nodeName] = append(nodeToDaemonPods[nodeName], daemonPod)
 	}
 	return nodeToDaemonPods, nil
 }

pkg/controller/deployment/sync.go

@@ -174,10 +174,14 @@ func (dc *DeploymentController) addHashKeyToRSAndPods(rs extensions.ReplicaSet)
 		return nil, fmt.Errorf("error in converting selector to label selector for replica set %s: %s", updatedRS.Name, err)
 	}
 	options := api.ListOptions{LabelSelector: selector}
-	podList, err := dc.podStore.Pods(namespace).List(options.LabelSelector)
+	pods, err := dc.podStore.Pods(namespace).List(options.LabelSelector)
 	if err != nil {
 		return nil, fmt.Errorf("error in getting pod list for namespace %s and list options %+v: %s", namespace, options, err)
 	}
+	podList := api.PodList{Items: make([]api.Pod, 0, len(pods))}
+	for i := range pods {
+		podList.Items = append(podList.Items, *pods[i])
+	}
 	allPodsLabeled := false
 	if allPodsLabeled, err = deploymentutil.LabelPodsWithHash(&podList, updatedRS, dc.client, namespace, hash); err != nil {
 		return nil, fmt.Errorf("error in adding template hash label %s to pods %+v: %s", hash, podList, err)
@@ -224,8 +228,12 @@ func (dc *DeploymentController) addHashKeyToRSAndPods(rs extensions.ReplicaSet)
 func (dc *DeploymentController) listPods(deployment *extensions.Deployment) (*api.PodList, error) {
 	return deploymentutil.ListPods(deployment,
 		func(namespace string, options api.ListOptions) (*api.PodList, error) {
-			podList, err := dc.podStore.Pods(namespace).List(options.LabelSelector)
-			return &podList, err
+			pods, err := dc.podStore.Pods(namespace).List(options.LabelSelector)
+			result := api.PodList{Items: make([]api.Pod, 0, len(pods))}
+			for i := range pods {
+				result.Items = append(result.Items, *pods[i])
+			}
+			return &result, err
 		})
 }
 

pkg/controller/deployment/util/deployment_util.go

@@ -633,7 +633,7 @@ func countAvailablePods(pods []api.Pod, minReadySeconds int32) int32 {
 
 // IsPodAvailable return true if the pod is available.
 func IsPodAvailable(pod *api.Pod, minReadySeconds int32, now time.Time) bool {
-	if !controller.IsPodActive(*pod) {
+	if !controller.IsPodActive(pod) {
 		return false
 	}
 	// Check if we've passed minReadySeconds since LastTransitionTime

pkg/controller/disruption/disruption.go

@@ -377,16 +377,16 @@ func (dc *DisruptionController) getPodsForPdb(pdb *policy.PodDisruptionBudget) (
 	if err != nil {
 		return []*api.Pod{}, err
 	}
-	podList, err := dc.podLister.Pods(pdb.Namespace).List(sel)
+	pods, err := dc.podLister.Pods(pdb.Namespace).List(sel)
 	if err != nil {
 		return []*api.Pod{}, err
 	}
-	pods := []*api.Pod{}
-	for i := range podList.Items {
-		pod := podList.Items[i]
-		pods = append(pods, &pod)
+	// TODO: Do we need to copy here?
+	result := make([]*api.Pod, 0, len(pods))
+	for i := range pods {
+		result = append(result, &(*pods[i]))
 	}
-	return pods, nil
+	return result, nil
 }
 
 func (dc *DisruptionController) worker() {

pkg/controller/endpoint/endpoints_controller.go

@@ -380,8 +380,9 @@ func (e *EndpointController) syncService(key string) {
 		}
 	}
 
-	for i := range pods.Items {
-		pod := &pods.Items[i]
+	for i := range pods {
+		// TODO: Do we need to copy here?
+		pod := &(*pods[i])
 
 		for i := range service.Spec.Ports {
 			servicePort := &service.Spec.Ports[i]

pkg/controller/job/jobcontroller.go

@@ -332,16 +332,16 @@ func (jm *JobController) syncJob(key string) error {
 	}
 	jobNeedsSync := jm.expectations.SatisfiedExpectations(jobKey)
 	selector, _ := unversioned.LabelSelectorAsSelector(job.Spec.Selector)
-	podList, err := jm.podStore.Pods(job.Namespace).List(selector)
+	pods, err := jm.podStore.Pods(job.Namespace).List(selector)
 	if err != nil {
 		glog.Errorf("Error getting pods for job %q: %v", key, err)
 		jm.queue.Add(key)
 		return err
 	}
 
-	activePods := controller.FilterActivePods(podList.Items)
+	activePods := controller.FilterActivePods(pods)
 	active := int32(len(activePods))
-	succeeded, failed := getStatus(podList.Items)
+	succeeded, failed := getStatus(pods)
 	conditions := len(job.Status.Conditions)
 	if job.Status.StartTime == nil {
 		now := unversioned.Now()
@@ -450,7 +450,7 @@ func newCondition(conditionType batch.JobConditionType, reason, message string)
 }
 
 // getStatus returns no of succeeded and failed pods running a job
-func getStatus(pods []api.Pod) (succeeded, failed int32) {
+func getStatus(pods []*api.Pod) (succeeded, failed int32) {
 	succeeded = int32(filterPods(pods, api.PodSucceeded))
 	failed = int32(filterPods(pods, api.PodFailed))
 	return
@@ -458,6 +458,7 @@ func getStatus(pods []api.Pod) (succeeded, failed int32) {
 
 // manageJob is the core method responsible for managing the number of running
 // pods according to what is specified in the job.Spec.
+// Does NOT modify <activePods>.
 func (jm *JobController) manageJob(activePods []*api.Pod, succeeded int32, job *batch.Job) int32 {
 	var activeLock sync.Mutex
 	active := int32(len(activePods))
@@ -550,7 +551,7 @@ func (jm *JobController) updateJobStatus(job *batch.Job) error {
 }
 
 // filterPods returns pods based on their phase.
-func filterPods(pods []api.Pod, phase api.PodPhase) int {
+func filterPods(pods []*api.Pod, phase api.PodPhase) int {
 	result := 0
 	for i := range pods {
 		if phase == pods[i].Status.Phase {

pkg/controller/petset/pet_set.go

@@ -218,15 +218,16 @@ func (psc *PetSetController) getPodsForPetSet(ps *apps.PetSet) ([]*api.Pod, erro
 	if err != nil {
 		return []*api.Pod{}, err
 	}
-	petList, err := psc.podStore.Pods(ps.Namespace).List(sel)
+	pods, err := psc.podStore.Pods(ps.Namespace).List(sel)
 	if err != nil {
 		return []*api.Pod{}, err
 	}
-	pods := []*api.Pod{}
-	for _, p := range petList.Items {
-		pods = append(pods, &p)
+	// TODO: Do we need to copy?
+	result := make([]*api.Pod, 0, len(pods))
+	for i := range pods {
+		result = append(result, &(*pods[i]))
 	}
-	return pods, nil
+	return result, nil
 }
 
 // getPetSetForPod returns the pet set managing the given pod.

pkg/controller/replicaset/replica_set.go

@@ -458,6 +458,7 @@ func (rsc *ReplicaSetController) worker() {
 }
 
 // manageReplicas checks and updates replicas for the given ReplicaSet.
+// Does NOT modify <filteredPods>.
 func (rsc *ReplicaSetController) manageReplicas(filteredPods []*api.Pod, rs *extensions.ReplicaSet) {
 	diff := len(filteredPods) - int(rs.Spec.Replicas)
 	rsKey, err := controller.KeyFunc(rs)
@@ -593,19 +594,21 @@ func (rsc *ReplicaSetController) syncReplicaSet(key string) error {
 		return err
 	}
 
+	// NOTE: filteredPods are pointing to objects from cache - if you need to
+	// modify them, you need to copy it first.
 	// TODO: Do the List and Filter in a single pass, or use an index.
 	var filteredPods []*api.Pod
 	if rsc.garbageCollectorEnabled {
 		// list all pods to include the pods that don't match the rs`s selector
 		// anymore but has the stale controller ref.
-		podList, err := rsc.podStore.Pods(rs.Namespace).List(labels.Everything())
+		pods, err := rsc.podStore.Pods(rs.Namespace).List(labels.Everything())
 		if err != nil {
 			glog.Errorf("Error getting pods for rs %q: %v", key, err)
 			rsc.queue.Add(key)
 			return err
 		}
 		cm := controller.NewPodControllerRefManager(rsc.podControl, rs.ObjectMeta, selector, getRSKind())
-		matchesAndControlled, matchesNeedsController, controlledDoesNotMatch := cm.Classify(podList.Items)
+		matchesAndControlled, matchesNeedsController, controlledDoesNotMatch := cm.Classify(pods)
 		for _, pod := range matchesNeedsController {
 			err := cm.AdoptPod(pod)
 			// continue to next pod if adoption fails.
@@ -636,13 +639,13 @@ func (rsc *ReplicaSetController) syncReplicaSet(key string) error {
 			return aggregate
 		}
 	} else {
-		podList, err := rsc.podStore.Pods(rs.Namespace).List(selector)
+		pods, err := rsc.podStore.Pods(rs.Namespace).List(selector)
 		if err != nil {
 			glog.Errorf("Error getting pods for rs %q: %v", key, err)
 			rsc.queue.Add(key)
 			return err
 		}
-		filteredPods = controller.FilterActivePods(podList.Items)
+		filteredPods = controller.FilterActivePods(pods)
 	}
 
 	if rsNeedsSync && rs.DeletionTimestamp == nil {

pkg/controller/replication/replication_controller.go

@@ -479,6 +479,7 @@ func (rm *ReplicationManager) worker() {
 }
 
 // manageReplicas checks and updates replicas for the given replication controller.
+// Does NOT modify <filteredPods>.
 func (rm *ReplicationManager) manageReplicas(filteredPods []*api.Pod, rc *api.ReplicationController) {
 	diff := len(filteredPods) - int(rc.Spec.Replicas)
 	rcKey, err := controller.KeyFunc(rc)
@@ -617,19 +618,21 @@ func (rm *ReplicationManager) syncReplicationController(key string) error {
 	rcNeedsSync := rm.expectations.SatisfiedExpectations(rcKey)
 	trace.Step("Expectations restored")
 
+	// NOTE: filteredPods are pointing to objects from cache - if you need to
+	// modify them, you need to copy it first.
 	// TODO: Do the List and Filter in a single pass, or use an index.
 	var filteredPods []*api.Pod
 	if rm.garbageCollectorEnabled {
 		// list all pods to include the pods that don't match the rc's selector
 		// anymore but has the stale controller ref.
-		podList, err := rm.podStore.Pods(rc.Namespace).List(labels.Everything())
+		pods, err := rm.podStore.Pods(rc.Namespace).List(labels.Everything())
 		if err != nil {
 			glog.Errorf("Error getting pods for rc %q: %v", key, err)
 			rm.queue.Add(key)
 			return err
 		}
 		cm := controller.NewPodControllerRefManager(rm.podControl, rc.ObjectMeta, labels.Set(rc.Spec.Selector).AsSelector(), getRCKind())
-		matchesAndControlled, matchesNeedsController, controlledDoesNotMatch := cm.Classify(podList.Items)
+		matchesAndControlled, matchesNeedsController, controlledDoesNotMatch := cm.Classify(pods)
 		for _, pod := range matchesNeedsController {
 			err := cm.AdoptPod(pod)
 			// continue to next pod if adoption fails.
@@ -660,13 +663,13 @@ func (rm *ReplicationManager) syncReplicationController(key string) error {
 			return aggregate
 		}
 	} else {
-		podList, err := rm.podStore.Pods(rc.Namespace).List(labels.Set(rc.Spec.Selector).AsSelector())
+		pods, err := rm.podStore.Pods(rc.Namespace).List(labels.Set(rc.Spec.Selector).AsSelector())
 		if err != nil {
 			glog.Errorf("Error getting pods for rc %q: %v", key, err)
 			rm.queue.Add(key)
 			return err
 		}
-		filteredPods = controller.FilterActivePods(podList.Items)
+		filteredPods = controller.FilterActivePods(pods)
 	}
 
 	if rcNeedsSync && rc.DeletionTimestamp == nil {

test/e2e/framework/util.go

@@ -3166,7 +3166,7 @@ func waitForPodsInactive(ps *PodStore, interval, timeout time.Duration) error {
 	return wait.PollImmediate(interval, timeout, func() (bool, error) {
 		pods := ps.List()
 		for _, pod := range pods {
-			if controller.IsPodActive(*pod) {
+			if controller.IsPodActive(pod) {
 				return false, nil
 			}
 		}