Merge pull request #6039 from yifan-gu/readiness

kubelet: Add container readiness manager.

pkg/kubelet/container/container_reference_manager.go

@@ -36,9 +36,7 @@ type RefManager struct {
 // NewRefManager creates and returns a container reference manager
 // with empty contents.
 func NewRefManager() *RefManager {
-	c := RefManager{}
-	c.containerIDToRef = make(map[string]*api.ObjectReference)
-	return &c
+	return &RefManager{containerIDToRef: make(map[string]*api.ObjectReference)}
 }
 
 // SetRef stores a reference to a pod's container, associating it with the given container ID.

pkg/kubelet/container/readiness_manager.go

@@ -0,0 +1,59 @@
+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 container
+
+import "sync"
+
+// ReadinessManager maintains the readiness information(probe results) of
+// containers over time to allow for implementation of health thresholds.
+// This manager is thread-safe, no locks are necessary for the caller.
+type ReadinessManager struct {
+	// guards states
+	sync.RWMutex
+	// TODO(yifan): To use strong type.
+	states map[string]bool
+}
+
+// NewReadinessManager creates ane returns a readiness manager with empty
+// contents.
+func NewReadinessManager() *ReadinessManager {
+	return &ReadinessManager{states: make(map[string]bool)}
+}
+
+// GetReadiness returns the readiness value for the container with the given ID.
+// If the readiness value is found, returns it.
+// If the readiness is not found, returns false.
+func (r *ReadinessManager) GetReadiness(id string) bool {
+	r.RLock()
+	defer r.RUnlock()
+	state, found := r.states[id]
+	return state && found
+}
+
+// SetReadiness sets the readiness value for the container with the given ID.
+func (r *ReadinessManager) SetReadiness(id string, value bool) {
+	r.Lock()
+	defer r.Unlock()
+	r.states[id] = value
+}
+
+// RemoveReadiness clears the readiness value for the container with the given ID.
+func (r *ReadinessManager) RemoveReadiness(id string) {
+	r.Lock()
+	defer r.Unlock()
+	delete(r.states, id)
+}

pkg/kubelet/kubelet.go

@@ -213,6 +213,7 @@ func NewMainKubelet(
 		resyncInterval:         resyncInterval,
 		podInfraContainerImage: podInfraContainerImage,
 		containerRefManager:    kubecontainer.NewRefManager(),
+		readinessManager:       kubecontainer.NewReadinessManager(),
 		runner:                 dockertools.NewDockerContainerCommandRunner(dockerClient),
 		httpClient:             &http.Client{},
 		pullQPS:                pullQPS,
@@ -224,7 +225,6 @@ func NewMainKubelet(
 		nodeLister:             nodeLister,
 		masterServiceNamespace: masterServiceNamespace,
 		prober:                 newProbeHolder(),
-		readiness:                      newReadinessStates(),
 		streamingConnectionIdleTimeout: streamingConnectionIdleTimeout,
 		recorder:                       recorder,
 		cadvisor:                       cadvisorInterface,
@@ -326,8 +326,8 @@ type Kubelet struct {
 
 	// Probe runner holder
 	prober probeHolder
-	// Container readiness state holder
-	readiness *readinessStates
+	// Container readiness state manager.
+	readinessManager *kubecontainer.ReadinessManager
 
 	// How long to keep idle streaming command execution/port forwarding
 	// connections open before terminating them
@@ -818,7 +818,7 @@ func (kl *Kubelet) killContainer(c *kubecontainer.Container) error {
 
 func (kl *Kubelet) killContainerByID(ID string) error {
 	glog.V(2).Infof("Killing container with id %q", ID)
-	kl.readiness.remove(ID)
+	kl.readinessManager.RemoveReadiness(ID)
 	err := kl.dockerClient.StopContainer(ID, 10)
 
 	ref, ok := kl.containerRefManager.GetRef(ID)
@@ -986,7 +986,7 @@ func (kl *Kubelet) shouldContainerBeRestarted(container *api.Container, pod *api
 	}
 	// set dead containers to unready state
 	for _, c := range recentContainers {
-		kl.readiness.remove(c.ID)
+		kl.readinessManager.RemoveReadiness(c.ID)
 	}
 
 	if len(recentContainers) > 0 {
@@ -1915,7 +1915,8 @@ func (kl *Kubelet) generatePodStatusByPod(pod *api.Pod) (api.PodStatus, error) {
 	for _, c := range spec.Containers {
 		for i, st := range podStatus.ContainerStatuses {
 			if st.Name == c.Name {
-				podStatus.ContainerStatuses[i].Ready = kl.readiness.IsReady(st)
+				ready := st.State.Running != nil && kl.readinessManager.GetReadiness(strings.TrimPrefix(st.ContainerID, "docker://"))
+				podStatus.ContainerStatuses[i].Ready = ready
 				break
 			}
 		}

pkg/kubelet/kubelet_test.go

@@ -101,7 +101,7 @@ func newTestKubelet(t *testing.T) *TestKubelet {
 	kubelet.masterServiceNamespace = api.NamespaceDefault
 	kubelet.serviceLister = testServiceLister{}
 	kubelet.nodeLister = testNodeLister{}
-	kubelet.readiness = newReadinessStates()
+	kubelet.readinessManager = kubecontainer.NewReadinessManager()
 	kubelet.recorder = fakeRecorder
 	kubelet.statusManager = newStatusManager(fakeKubeClient)
 	if err := kubelet.setupDataDirs(); err != nil {
@@ -369,7 +369,7 @@ func TestKillContainerWithError(t *testing.T) {
 	testKubelet := newTestKubelet(t)
 	kubelet := testKubelet.kubelet
 	for _, c := range fakeDocker.ContainerList {
-		kubelet.readiness.set(c.ID, true)
+		kubelet.readinessManager.SetReadiness(c.ID, true)
 	}
 	kubelet.dockerClient = fakeDocker
 	c := apiContainerToContainer(fakeDocker.ContainerList[0])
@@ -380,11 +380,13 @@ func TestKillContainerWithError(t *testing.T) {
 	verifyCalls(t, fakeDocker, []string{"stop"})
 	killedContainer := containers[0]
 	liveContainer := containers[1]
-	if _, found := kubelet.readiness.states[killedContainer.ID]; found {
-		t.Errorf("exepcted container entry ID '%v' to not be found. states: %+v", killedContainer.ID, kubelet.readiness.states)
+	ready := kubelet.readinessManager.GetReadiness(killedContainer.ID)
+	if ready {
+		t.Errorf("exepcted container entry ID '%v' to not be found. states: %+v", killedContainer.ID, ready)
 	}
-	if _, found := kubelet.readiness.states[liveContainer.ID]; !found {
-		t.Errorf("exepcted container entry ID '%v' to be found. states: %+v", liveContainer.ID, kubelet.readiness.states)
+	ready = kubelet.readinessManager.GetReadiness(liveContainer.ID)
+	if !ready {
+		t.Errorf("exepcted container entry ID '%v' to be found. states: %+v", liveContainer.ID, ready)
 	}
 }
 
@@ -407,7 +409,7 @@ func TestKillContainer(t *testing.T) {
 		Name: "foobar",
 	}
 	for _, c := range fakeDocker.ContainerList {
-		kubelet.readiness.set(c.ID, true)
+		kubelet.readinessManager.SetReadiness(c.ID, true)
 	}
 
 	c := apiContainerToContainer(fakeDocker.ContainerList[0])
@@ -418,11 +420,13 @@ func TestKillContainer(t *testing.T) {
 	verifyCalls(t, fakeDocker, []string{"stop"})
 	killedContainer := containers[0]
 	liveContainer := containers[1]
-	if _, found := kubelet.readiness.states[killedContainer.ID]; found {
-		t.Errorf("exepcted container entry ID '%v' to not be found. states: %+v", killedContainer.ID, kubelet.readiness.states)
+	ready := kubelet.readinessManager.GetReadiness(killedContainer.ID)
+	if ready {
+		t.Errorf("exepcted container entry ID '%v' to not be found. states: %+v", killedContainer.ID, ready)
 	}
-	if _, found := kubelet.readiness.states[liveContainer.ID]; !found {
-		t.Errorf("exepcted container entry ID '%v' to be found. states: %+v", liveContainer.ID, kubelet.readiness.states)
+	ready = kubelet.readinessManager.GetReadiness(liveContainer.ID)
+	if !ready {
+		t.Errorf("exepcted container entry ID '%v' to be found. states: %+v", liveContainer.ID, ready)
 	}
 }
 

pkg/kubelet/probe.go

@@ -19,8 +19,6 @@ package kubelet
 import (
 	"fmt"
 	"strconv"
-	"strings"
-	"sync"
 	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
@@ -45,12 +43,12 @@ func (kl *Kubelet) probeContainer(pod *api.Pod, status api.PodStatus, container
 	live, err := kl.probeContainerLiveness(pod, status, container, createdAt)
 	if err != nil {
 		glog.V(1).Infof("Liveness probe errored: %v", err)
-		kl.readiness.set(containerID, false)
+		kl.readinessManager.SetReadiness(containerID, false)
 		return probe.Unknown, err
 	}
 	if live != probe.Success {
 		glog.V(1).Infof("Liveness probe unsuccessful: %v", live)
-		kl.readiness.set(containerID, false)
+		kl.readinessManager.SetReadiness(containerID, false)
 		return live, nil
 	}
 
@@ -58,12 +56,12 @@ func (kl *Kubelet) probeContainer(pod *api.Pod, status api.PodStatus, container
 	ready, err := kl.probeContainerReadiness(pod, status, container, createdAt)
 	if err == nil && ready == probe.Success {
 		glog.V(3).Infof("Readiness probe successful: %v", ready)
-		kl.readiness.set(containerID, true)
+		kl.readinessManager.SetReadiness(containerID, true)
 		return probe.Success, nil
 	}
 
 	glog.V(1).Infof("Readiness probe failed/errored: %v, %v", ready, err)
-	kl.readiness.set(containerID, false)
+	kl.readinessManager.SetReadiness(containerID, false)
 
 	ref, ok := kl.containerRefManager.GetRef(containerID)
 	if !ok {
@@ -204,44 +202,6 @@ func (eic execInContainer) SetDir(dir string) {
 	//unimplemented
 }
 
-// This will eventually maintain info about probe results over time
-// to allow for implementation of health thresholds
-func newReadinessStates() *readinessStates {
-	return &readinessStates{states: make(map[string]bool)}
-}
-
-type readinessStates struct {
-	// guards states
-	sync.RWMutex
-	states map[string]bool
-}
-
-func (r *readinessStates) IsReady(c api.ContainerStatus) bool {
-	if c.State.Running == nil {
-		return false
-	}
-	return r.get(strings.TrimPrefix(c.ContainerID, "docker://"))
-}
-
-func (r *readinessStates) get(key string) bool {
-	r.RLock()
-	defer r.RUnlock()
-	state, found := r.states[key]
-	return state && found
-}
-
-func (r *readinessStates) set(key string, value bool) {
-	r.Lock()
-	defer r.Unlock()
-	r.states[key] = value
-}
-
-func (r *readinessStates) remove(key string) {
-	r.Lock()
-	defer r.Unlock()
-	delete(r.states, key)
-}
-
 func newProbeHolder() probeHolder {
 	return probeHolder{
 		exec: execprobe.New(),

pkg/kubelet/probe_test.go

@@ -147,7 +147,7 @@ func (p fakeExecProber) Probe(_ exec.Cmd) (probe.Result, error) {
 
 func makeTestKubelet(result probe.Result, err error) *Kubelet {
 	return &Kubelet{
-		readiness: newReadinessStates(),
+		readinessManager: kubecontainer.NewReadinessManager(),
 		prober: probeHolder{
 			exec: fakeExecProber{
 				result: result,
@@ -412,8 +412,8 @@ func TestProbeContainer(t *testing.T) {
 		if test.expectedResult != result {
 			t.Errorf("Expected result was %v but probeContainer() returned %v", test.expectedResult, result)
 		}
-		if test.expectedReadiness != kl.readiness.get(dc.ID) {
-			t.Errorf("Expected readiness was %v but probeContainer() set %v", test.expectedReadiness, kl.readiness.get(dc.ID))
+		if test.expectedReadiness != kl.readinessManager.GetReadiness(dc.ID) {
+			t.Errorf("Expected readiness was %v but probeContainer() set %v", test.expectedReadiness, kl.readinessManager.GetReadiness(dc.ID))
 		}
 	}
 }