Add generated file

This PR adds generated files under pkg/client and vendor folder.

vendor/k8s.io/kubernetes/pkg/kubelet/pleg/generic.go

@@ -0,0 +1,464 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package pleg
+
+import (
+	"fmt"
+	"sync/atomic"
+	"time"
+
+	"github.com/golang/glog"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/clock"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apimachinery/pkg/util/wait"
+	runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
+	kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
+	"k8s.io/kubernetes/pkg/kubelet/metrics"
+)
+
+// GenericPLEG is an extremely simple generic PLEG that relies solely on
+// periodic listing to discover container changes. It should be used
+// as temporary replacement for container runtimes do not support a proper
+// event generator yet.
+//
+// Note that GenericPLEG assumes that a container would not be created,
+// terminated, and garbage collected within one relist period. If such an
+// incident happens, GenenricPLEG would miss all events regarding this
+// container. In the case of relisting failure, the window may become longer.
+// Note that this assumption is not unique -- many kubelet internal components
+// rely on terminated containers as tombstones for bookkeeping purposes. The
+// garbage collector is implemented to work with such situations. However, to
+// guarantee that kubelet can handle missing container events, it is
+// recommended to set the relist period short and have an auxiliary, longer
+// periodic sync in kubelet as the safety net.
+type GenericPLEG struct {
+	// The period for relisting.
+	relistPeriod time.Duration
+	// The container runtime.
+	runtime kubecontainer.Runtime
+	// The channel from which the subscriber listens events.
+	eventChannel chan *PodLifecycleEvent
+	// The internal cache for pod/container information.
+	podRecords podRecords
+	// Time of the last relisting.
+	relistTime atomic.Value
+	// Cache for storing the runtime states required for syncing pods.
+	cache kubecontainer.Cache
+	// For testability.
+	clock clock.Clock
+	// Pods that failed to have their status retrieved during a relist. These pods will be
+	// retried during the next relisting.
+	podsToReinspect map[types.UID]*kubecontainer.Pod
+}
+
+// plegContainerState has a one-to-one mapping to the
+// kubecontainer.ContainerState except for the non-existent state. This state
+// is introduced here to complete the state transition scenarios.
+type plegContainerState string
+
+const (
+	plegContainerRunning     plegContainerState = "running"
+	plegContainerExited      plegContainerState = "exited"
+	plegContainerUnknown     plegContainerState = "unknown"
+	plegContainerNonExistent plegContainerState = "non-existent"
+
+	// The threshold needs to be greater than the relisting period + the
+	// relisting time, which can vary significantly. Set a conservative
+	// threshold to avoid flipping between healthy and unhealthy.
+	relistThreshold = 3 * time.Minute
+)
+
+func convertState(state kubecontainer.ContainerState) plegContainerState {
+	switch state {
+	case kubecontainer.ContainerStateCreated:
+		// kubelet doesn't use the "created" state yet, hence convert it to "unknown".
+		return plegContainerUnknown
+	case kubecontainer.ContainerStateRunning:
+		return plegContainerRunning
+	case kubecontainer.ContainerStateExited:
+		return plegContainerExited
+	case kubecontainer.ContainerStateUnknown:
+		return plegContainerUnknown
+	default:
+		panic(fmt.Sprintf("unrecognized container state: %v", state))
+	}
+}
+
+type podRecord struct {
+	old     *kubecontainer.Pod
+	current *kubecontainer.Pod
+}
+
+type podRecords map[types.UID]*podRecord
+
+func NewGenericPLEG(runtime kubecontainer.Runtime, channelCapacity int,
+	relistPeriod time.Duration, cache kubecontainer.Cache, clock clock.Clock) PodLifecycleEventGenerator {
+	return &GenericPLEG{
+		relistPeriod: relistPeriod,
+		runtime:      runtime,
+		eventChannel: make(chan *PodLifecycleEvent, channelCapacity),
+		podRecords:   make(podRecords),
+		cache:        cache,
+		clock:        clock,
+	}
+}
+
+// Returns a channel from which the subscriber can receive PodLifecycleEvent
+// events.
+// TODO: support multiple subscribers.
+func (g *GenericPLEG) Watch() chan *PodLifecycleEvent {
+	return g.eventChannel
+}
+
+// Start spawns a goroutine to relist periodically.
+func (g *GenericPLEG) Start() {
+	go wait.Until(g.relist, g.relistPeriod, wait.NeverStop)
+}
+
+func (g *GenericPLEG) Healthy() (bool, error) {
+	relistTime := g.getRelistTime()
+	elapsed := g.clock.Since(relistTime)
+	if elapsed > relistThreshold {
+		return false, fmt.Errorf("pleg was last seen active %v ago; threshold is %v", elapsed, relistThreshold)
+	}
+	return true, nil
+}
+
+func generateEvents(podID types.UID, cid string, oldState, newState plegContainerState) []*PodLifecycleEvent {
+	if newState == oldState {
+		return nil
+	}
+
+	glog.V(4).Infof("GenericPLEG: %v/%v: %v -> %v", podID, cid, oldState, newState)
+	switch newState {
+	case plegContainerRunning:
+		return []*PodLifecycleEvent{{ID: podID, Type: ContainerStarted, Data: cid}}
+	case plegContainerExited:
+		return []*PodLifecycleEvent{{ID: podID, Type: ContainerDied, Data: cid}}
+	case plegContainerUnknown:
+		return []*PodLifecycleEvent{{ID: podID, Type: ContainerChanged, Data: cid}}
+	case plegContainerNonExistent:
+		switch oldState {
+		case plegContainerExited:
+			// We already reported that the container died before.
+			return []*PodLifecycleEvent{{ID: podID, Type: ContainerRemoved, Data: cid}}
+		default:
+			return []*PodLifecycleEvent{{ID: podID, Type: ContainerDied, Data: cid}, {ID: podID, Type: ContainerRemoved, Data: cid}}
+		}
+	default:
+		panic(fmt.Sprintf("unrecognized container state: %v", newState))
+	}
+}
+
+func (g *GenericPLEG) getRelistTime() time.Time {
+	val := g.relistTime.Load()
+	if val == nil {
+		return time.Time{}
+	}
+	return val.(time.Time)
+}
+
+func (g *GenericPLEG) updateRelistTime(timestamp time.Time) {
+	g.relistTime.Store(timestamp)
+}
+
+// relist queries the container runtime for list of pods/containers, compare
+// with the internal pods/containers, and generates events accordingly.
+func (g *GenericPLEG) relist() {
+	glog.V(5).Infof("GenericPLEG: Relisting")
+
+	if lastRelistTime := g.getRelistTime(); !lastRelistTime.IsZero() {
+		metrics.PLEGRelistInterval.Observe(metrics.SinceInMicroseconds(lastRelistTime))
+	}
+
+	timestamp := g.clock.Now()
+	defer func() {
+		metrics.PLEGRelistLatency.Observe(metrics.SinceInMicroseconds(timestamp))
+	}()
+
+	// Get all the pods.
+	podList, err := g.runtime.GetPods(true)
+	if err != nil {
+		glog.Errorf("GenericPLEG: Unable to retrieve pods: %v", err)
+		return
+	}
+
+	g.updateRelistTime(timestamp)
+
+	pods := kubecontainer.Pods(podList)
+	g.podRecords.setCurrent(pods)
+
+	// Compare the old and the current pods, and generate events.
+	eventsByPodID := map[types.UID][]*PodLifecycleEvent{}
+	for pid := range g.podRecords {
+		oldPod := g.podRecords.getOld(pid)
+		pod := g.podRecords.getCurrent(pid)
+		// Get all containers in the old and the new pod.
+		allContainers := getContainersFromPods(oldPod, pod)
+		for _, container := range allContainers {
+			events := computeEvents(oldPod, pod, &container.ID)
+			for _, e := range events {
+				updateEvents(eventsByPodID, e)
+			}
+		}
+	}
+
+	var needsReinspection map[types.UID]*kubecontainer.Pod
+	if g.cacheEnabled() {
+		needsReinspection = make(map[types.UID]*kubecontainer.Pod)
+	}
+
+	// If there are events associated with a pod, we should update the
+	// podCache.
+	for pid, events := range eventsByPodID {
+		pod := g.podRecords.getCurrent(pid)
+		if g.cacheEnabled() {
+			// updateCache() will inspect the pod and update the cache. If an
+			// error occurs during the inspection, we want PLEG to retry again
+			// in the next relist. To achieve this, we do not update the
+			// associated podRecord of the pod, so that the change will be
+			// detect again in the next relist.
+			// TODO: If many pods changed during the same relist period,
+			// inspecting the pod and getting the PodStatus to update the cache
+			// serially may take a while. We should be aware of this and
+			// parallelize if needed.
+			if err := g.updateCache(pod, pid); err != nil {
+				glog.Errorf("PLEG: Ignoring events for pod %s/%s: %v", pod.Name, pod.Namespace, err)
+
+				// make sure we try to reinspect the pod during the next relisting
+				needsReinspection[pid] = pod
+
+				continue
+			} else if _, found := g.podsToReinspect[pid]; found {
+				// this pod was in the list to reinspect and we did so because it had events, so remove it
+				// from the list (we don't want the reinspection code below to inspect it a second time in
+				// this relist execution)
+				delete(g.podsToReinspect, pid)
+			}
+		}
+		// Update the internal storage and send out the events.
+		g.podRecords.update(pid)
+		for i := range events {
+			// Filter out events that are not reliable and no other components use yet.
+			if events[i].Type == ContainerChanged {
+				continue
+			}
+			g.eventChannel <- events[i]
+		}
+	}
+
+	if g.cacheEnabled() {
+		// reinspect any pods that failed inspection during the previous relist
+		if len(g.podsToReinspect) > 0 {
+			glog.V(5).Infof("GenericPLEG: Reinspecting pods that previously failed inspection")
+			for pid, pod := range g.podsToReinspect {
+				if err := g.updateCache(pod, pid); err != nil {
+					glog.Errorf("PLEG: pod %s/%s failed reinspection: %v", pod.Name, pod.Namespace, err)
+					needsReinspection[pid] = pod
+				}
+			}
+		}
+
+		// Update the cache timestamp.  This needs to happen *after*
+		// all pods have been properly updated in the cache.
+		g.cache.UpdateTime(timestamp)
+	}
+
+	// make sure we retain the list of pods that need reinspecting the next time relist is called
+	g.podsToReinspect = needsReinspection
+}
+
+func getContainersFromPods(pods ...*kubecontainer.Pod) []*kubecontainer.Container {
+	cidSet := sets.NewString()
+	var containers []*kubecontainer.Container
+	for _, p := range pods {
+		if p == nil {
+			continue
+		}
+		for _, c := range p.Containers {
+			cid := string(c.ID.ID)
+			if cidSet.Has(cid) {
+				continue
+			}
+			cidSet.Insert(cid)
+			containers = append(containers, c)
+		}
+		// Update sandboxes as containers
+		// TODO: keep track of sandboxes explicitly.
+		for _, c := range p.Sandboxes {
+			cid := string(c.ID.ID)
+			if cidSet.Has(cid) {
+				continue
+			}
+			cidSet.Insert(cid)
+			containers = append(containers, c)
+		}
+
+	}
+	return containers
+}
+
+func computeEvents(oldPod, newPod *kubecontainer.Pod, cid *kubecontainer.ContainerID) []*PodLifecycleEvent {
+	var pid types.UID
+	if oldPod != nil {
+		pid = oldPod.ID
+	} else if newPod != nil {
+		pid = newPod.ID
+	}
+	oldState := getContainerState(oldPod, cid)
+	newState := getContainerState(newPod, cid)
+	return generateEvents(pid, cid.ID, oldState, newState)
+}
+
+func (g *GenericPLEG) cacheEnabled() bool {
+	return g.cache != nil
+}
+
+// Preserve an older cached status' pod IP if the new status has no pod IP
+// and its sandboxes have exited
+func (g *GenericPLEG) getPodIP(pid types.UID, status *kubecontainer.PodStatus) string {
+	if status.IP != "" {
+		return status.IP
+	}
+
+	oldStatus, err := g.cache.Get(pid)
+	if err != nil || oldStatus.IP == "" {
+		return ""
+	}
+
+	for _, sandboxStatus := range status.SandboxStatuses {
+		// If at least one sandbox is ready, then use this status update's pod IP
+		if sandboxStatus.State == runtimeapi.PodSandboxState_SANDBOX_READY {
+			return status.IP
+		}
+	}
+
+	if len(status.SandboxStatuses) == 0 {
+		// Without sandboxes (which built-in runtimes like rkt don't report)
+		// look at all the container statuses, and if any containers are
+		// running then use the new pod IP
+		for _, containerStatus := range status.ContainerStatuses {
+			if containerStatus.State == kubecontainer.ContainerStateCreated || containerStatus.State == kubecontainer.ContainerStateRunning {
+				return status.IP
+			}
+		}
+	}
+
+	// For pods with no ready containers or sandboxes (like exited pods)
+	// use the old status' pod IP
+	return oldStatus.IP
+}
+
+func (g *GenericPLEG) updateCache(pod *kubecontainer.Pod, pid types.UID) error {
+	if pod == nil {
+		// The pod is missing in the current relist. This means that
+		// the pod has no visible (active or inactive) containers.
+		glog.V(4).Infof("PLEG: Delete status for pod %q", string(pid))
+		g.cache.Delete(pid)
+		return nil
+	}
+	timestamp := g.clock.Now()
+	// TODO: Consider adding a new runtime method
+	// GetPodStatus(pod *kubecontainer.Pod) so that Docker can avoid listing
+	// all containers again.
+	status, err := g.runtime.GetPodStatus(pod.ID, pod.Name, pod.Namespace)
+	glog.V(4).Infof("PLEG: Write status for %s/%s: %#v (err: %v)", pod.Name, pod.Namespace, status, err)
+	if err == nil {
+		// Preserve the pod IP across cache updates if the new IP is empty.
+		// When a pod is torn down, kubelet may race with PLEG and retrieve
+		// a pod status after network teardown, but the kubernetes API expects
+		// the completed pod's IP to be available after the pod is dead.
+		status.IP = g.getPodIP(pid, status)
+	}
+
+	g.cache.Set(pod.ID, status, err, timestamp)
+	return err
+}
+
+func updateEvents(eventsByPodID map[types.UID][]*PodLifecycleEvent, e *PodLifecycleEvent) {
+	if e == nil {
+		return
+	}
+	eventsByPodID[e.ID] = append(eventsByPodID[e.ID], e)
+}
+
+func getContainerState(pod *kubecontainer.Pod, cid *kubecontainer.ContainerID) plegContainerState {
+	// Default to the non-existent state.
+	state := plegContainerNonExistent
+	if pod == nil {
+		return state
+	}
+	c := pod.FindContainerByID(*cid)
+	if c != nil {
+		return convertState(c.State)
+	}
+	// Search through sandboxes too.
+	c = pod.FindSandboxByID(*cid)
+	if c != nil {
+		return convertState(c.State)
+	}
+
+	return state
+}
+
+func (pr podRecords) getOld(id types.UID) *kubecontainer.Pod {
+	r, ok := pr[id]
+	if !ok {
+		return nil
+	}
+	return r.old
+}
+
+func (pr podRecords) getCurrent(id types.UID) *kubecontainer.Pod {
+	r, ok := pr[id]
+	if !ok {
+		return nil
+	}
+	return r.current
+}
+
+func (pr podRecords) setCurrent(pods []*kubecontainer.Pod) {
+	for i := range pr {
+		pr[i].current = nil
+	}
+	for _, pod := range pods {
+		if r, ok := pr[pod.ID]; ok {
+			r.current = pod
+		} else {
+			pr[pod.ID] = &podRecord{current: pod}
+		}
+	}
+}
+
+func (pr podRecords) update(id types.UID) {
+	r, ok := pr[id]
+	if !ok {
+		return
+	}
+	pr.updateInternal(id, r)
+}
+
+func (pr podRecords) updateInternal(id types.UID, r *podRecord) {
+	if r.current == nil {
+		// Pod no longer exists; delete the entry.
+		delete(pr, id)
+		return
+	}
+	r.old = r.current
+	r.current = nil
+}