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/*
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 prober
import (
"sync"
v1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/types"
"k8s.io/apimachinery/pkg/util/sets"
"k8s.io/apimachinery/pkg/util/wait"
utilfeature "k8s.io/apiserver/pkg/util/feature"
"k8s.io/client-go/tools/record"
"k8s.io/component-base/metrics"
"k8s.io/klog"
"k8s.io/kubernetes/pkg/features"
kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
"k8s.io/kubernetes/pkg/kubelet/prober/results"
"k8s.io/kubernetes/pkg/kubelet/status"
"k8s.io/kubernetes/pkg/kubelet/util/format"
)
// ProberResults stores the cumulative number of a probe by result as prometheus metrics.
var ProberResults = metrics.NewCounterVec(
&metrics.CounterOpts{
Subsystem: "prober",
Name: "probe_total",
Help: "Cumulative number of a liveness, readiness or startup probe for a container by result.",
StabilityLevel: metrics.ALPHA,
},
[]string{"probe_type",
"result",
"container",
"pod",
"namespace",
"pod_uid"},
)
// Manager manages pod probing. It creates a probe "worker" for every container that specifies a
// probe (AddPod). The worker periodically probes its assigned container and caches the results. The
// manager use the cached probe results to set the appropriate Ready state in the PodStatus when
// requested (UpdatePodStatus). Updating probe parameters is not currently supported.
// TODO: Move liveness probing out of the runtime, to here.
type Manager interface {
// AddPod creates new probe workers for every container probe. This should be called for every
// pod created.
AddPod(pod *v1.Pod)
// RemovePod handles cleaning up the removed pod state, including terminating probe workers and
// deleting cached results.
RemovePod(pod *v1.Pod)
// CleanupPods handles cleaning up pods which should no longer be running.
// It takes a map of "desired pods" which should not be cleaned up.
CleanupPods(desiredPods map[types.UID]sets.Empty)
// UpdatePodStatus modifies the given PodStatus with the appropriate Ready state for each
// container based on container running status, cached probe results and worker states.
UpdatePodStatus(types.UID, *v1.PodStatus)
// Start starts the Manager sync loops.
Start()
}
type manager struct {
// Map of active workers for probes
workers map[probeKey]*worker
// Lock for accessing & mutating workers
workerLock sync.RWMutex
// The statusManager cache provides pod IP and container IDs for probing.
statusManager status.Manager
// readinessManager manages the results of readiness probes
readinessManager results.Manager
// livenessManager manages the results of liveness probes
livenessManager results.Manager
// startupManager manages the results of startup probes
startupManager results.Manager
// prober executes the probe actions.
prober *prober
}
// NewManager creates a Manager for pod probing.
func NewManager(
statusManager status.Manager,
livenessManager results.Manager,
startupManager results.Manager,
runner kubecontainer.ContainerCommandRunner,
refManager *kubecontainer.RefManager,
recorder record.EventRecorder) Manager {
prober := newProber(runner, refManager, recorder)
readinessManager := results.NewManager()
return &manager{
statusManager: statusManager,
prober: prober,
readinessManager: readinessManager,
livenessManager: livenessManager,
startupManager: startupManager,
workers: make(map[probeKey]*worker),
}
}
// Start syncing probe status. This should only be called once.
func (m *manager) Start() {
// Start syncing readiness.
go wait.Forever(m.updateReadiness, 0)
// Start syncing startup.
go wait.Forever(m.updateStartup, 0)
}
// Key uniquely identifying container probes
type probeKey struct {
podUID types.UID
containerName string
probeType probeType
}
// Type of probe (liveness, readiness or startup)
type probeType int
const (
liveness probeType = iota
readiness
startup
probeResultSuccessful string = "successful"
probeResultFailed string = "failed"
probeResultUnknown string = "unknown"
)
// For debugging.
func (t probeType) String() string {
switch t {
case readiness:
return "Readiness"
case liveness:
return "Liveness"
case startup:
return "Startup"
default:
return "UNKNOWN"
}
}
func (m *manager) AddPod(pod *v1.Pod) {
m.workerLock.Lock()
defer m.workerLock.Unlock()
key := probeKey{podUID: pod.UID}
for _, c := range pod.Spec.Containers {
key.containerName = c.Name
if c.StartupProbe != nil && utilfeature.DefaultFeatureGate.Enabled(features.StartupProbe) {
key.probeType = startup
if _, ok := m.workers[key]; ok {
klog.Errorf("Startup probe already exists! %v - %v",
format.Pod(pod), c.Name)
return
}
w := newWorker(m, startup, pod, c)
m.workers[key] = w
go w.run()
}
if c.ReadinessProbe != nil {
key.probeType = readiness
if _, ok := m.workers[key]; ok {
klog.Errorf("Readiness probe already exists! %v - %v",
format.Pod(pod), c.Name)
return
}
w := newWorker(m, readiness, pod, c)
m.workers[key] = w
go w.run()
}
if c.LivenessProbe != nil {
key.probeType = liveness
if _, ok := m.workers[key]; ok {
klog.Errorf("Liveness probe already exists! %v - %v",
format.Pod(pod), c.Name)
return
}
w := newWorker(m, liveness, pod, c)
m.workers[key] = w
go w.run()
}
}
}
func (m *manager) RemovePod(pod *v1.Pod) {
m.workerLock.RLock()
defer m.workerLock.RUnlock()
key := probeKey{podUID: pod.UID}
for _, c := range pod.Spec.Containers {
key.containerName = c.Name
for _, probeType := range [...]probeType{readiness, liveness, startup} {
key.probeType = probeType
if worker, ok := m.workers[key]; ok {
worker.stop()
}
}
}
}
func (m *manager) CleanupPods(desiredPods map[types.UID]sets.Empty) {
m.workerLock.RLock()
defer m.workerLock.RUnlock()
for key, worker := range m.workers {
if _, ok := desiredPods[key.podUID]; !ok {
worker.stop()
}
}
}
func (m *manager) UpdatePodStatus(podUID types.UID, podStatus *v1.PodStatus) {
for i, c := range podStatus.ContainerStatuses {
var ready bool
if c.State.Running == nil {
ready = false
} else if result, ok := m.readinessManager.Get(kubecontainer.ParseContainerID(c.ContainerID)); ok {
ready = result == results.Success
} else {
// The check whether there is a probe which hasn't run yet.
_, exists := m.getWorker(podUID, c.Name, readiness)
ready = !exists
}
podStatus.ContainerStatuses[i].Ready = ready
var started bool
if c.State.Running == nil {
started = false
} else if !utilfeature.DefaultFeatureGate.Enabled(features.StartupProbe) {
// the container is running, assume it is started if the StartupProbe feature is disabled
started = true
} else if result, ok := m.startupManager.Get(kubecontainer.ParseContainerID(c.ContainerID)); ok {
started = result == results.Success
} else {
// The check whether there is a probe which hasn't run yet.
_, exists := m.getWorker(podUID, c.Name, startup)
started = !exists
}
podStatus.ContainerStatuses[i].Started = &started
}
// init containers are ready if they have exited with success or if a readiness probe has
// succeeded.
for i, c := range podStatus.InitContainerStatuses {
var ready bool
if c.State.Terminated != nil && c.State.Terminated.ExitCode == 0 {
ready = true
}
podStatus.InitContainerStatuses[i].Ready = ready
}
}
func (m *manager) getWorker(podUID types.UID, containerName string, probeType probeType) (*worker, bool) {
m.workerLock.RLock()
defer m.workerLock.RUnlock()
worker, ok := m.workers[probeKey{podUID, containerName, probeType}]
return worker, ok
}
// Called by the worker after exiting.
func (m *manager) removeWorker(podUID types.UID, containerName string, probeType probeType) {
m.workerLock.Lock()
defer m.workerLock.Unlock()
delete(m.workers, probeKey{podUID, containerName, probeType})
}
// workerCount returns the total number of probe workers. For testing.
func (m *manager) workerCount() int {
m.workerLock.RLock()
defer m.workerLock.RUnlock()
return len(m.workers)
}
func (m *manager) updateReadiness() {
update := <-m.readinessManager.Updates()
ready := update.Result == results.Success
m.statusManager.SetContainerReadiness(update.PodUID, update.ContainerID, ready)
}
func (m *manager) updateStartup() {
update := <-m.startupManager.Updates()
started := update.Result == results.Success
m.statusManager.SetContainerStartup(update.PodUID, update.ContainerID, started)
}
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