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kubelet.go
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kubelet.go
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/*
Copyright 2015 The Kubernetes Authors 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 kubelet
// Note: if you change code in this file, you might need to change code in
// contrib/mesos/pkg/executor/.
import (
"bytes"
"errors"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"os"
"path"
"sort"
"strings"
"sync"
"time"
"github.com/golang/glog"
cadvisorApi "github.com/google/cadvisor/info/v1"
"k8s.io/kubernetes/pkg/api"
apierrors "k8s.io/kubernetes/pkg/api/errors"
"k8s.io/kubernetes/pkg/api/resource"
"k8s.io/kubernetes/pkg/api/unversioned"
"k8s.io/kubernetes/pkg/api/validation"
"k8s.io/kubernetes/pkg/client/cache"
"k8s.io/kubernetes/pkg/client/record"
client "k8s.io/kubernetes/pkg/client/unversioned"
"k8s.io/kubernetes/pkg/cloudprovider"
"k8s.io/kubernetes/pkg/fieldpath"
"k8s.io/kubernetes/pkg/fields"
"k8s.io/kubernetes/pkg/kubelet/cadvisor"
kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
"k8s.io/kubernetes/pkg/kubelet/dockertools"
"k8s.io/kubernetes/pkg/kubelet/envvars"
"k8s.io/kubernetes/pkg/kubelet/metrics"
"k8s.io/kubernetes/pkg/kubelet/network"
"k8s.io/kubernetes/pkg/kubelet/rkt"
"k8s.io/kubernetes/pkg/kubelet/status"
kubeletTypes "k8s.io/kubernetes/pkg/kubelet/types"
kubeletUtil "k8s.io/kubernetes/pkg/kubelet/util"
"k8s.io/kubernetes/pkg/labels"
"k8s.io/kubernetes/pkg/runtime"
"k8s.io/kubernetes/pkg/types"
"k8s.io/kubernetes/pkg/util"
"k8s.io/kubernetes/pkg/util/bandwidth"
utilErrors "k8s.io/kubernetes/pkg/util/errors"
kubeio "k8s.io/kubernetes/pkg/util/io"
"k8s.io/kubernetes/pkg/util/mount"
nodeutil "k8s.io/kubernetes/pkg/util/node"
"k8s.io/kubernetes/pkg/util/oom"
"k8s.io/kubernetes/pkg/util/procfs"
"k8s.io/kubernetes/pkg/util/sets"
"k8s.io/kubernetes/pkg/version"
"k8s.io/kubernetes/pkg/volume"
"k8s.io/kubernetes/pkg/watch"
"k8s.io/kubernetes/plugin/pkg/scheduler/algorithm/predicates"
"k8s.io/kubernetes/third_party/golang/expansion"
)
const (
// Max amount of time to wait for the container runtime to come up.
maxWaitForContainerRuntime = 5 * time.Minute
// nodeStatusUpdateRetry specifies how many times kubelet retries when posting node status failed.
nodeStatusUpdateRetry = 5
// Location of container logs.
containerLogsDir = "/var/log/containers"
// max backoff period
maxContainerBackOff = 300 * time.Second
// Capacity of the channel for storing pods to kill. A small number should
// suffice because a goroutine is dedicated to check the channel and does
// not block on anything else.
podKillingChannelCapacity = 50
// system default DNS resolver configuration
ResolvConfDefault = "/etc/resolv.conf"
// Minimum period for performing global cleanup tasks, i.e., housekeeping
// will not be performed more than once per housekeepingMinimumPeriod.
housekeepingMinimumPeriod = time.Second * 2
etcHostsPath = "/etc/hosts"
)
var (
// ErrContainerNotFound returned when a container in the given pod with the
// given container name was not found, amongst those managed by the kubelet.
ErrContainerNotFound = errors.New("no matching container")
)
// SyncHandler is an interface implemented by Kubelet, for testability
type SyncHandler interface {
HandlePodAdditions(pods []*api.Pod)
HandlePodUpdates(pods []*api.Pod)
HandlePodDeletions(pods []*api.Pod)
HandlePodSyncs(pods []*api.Pod)
HandlePodCleanups() error
}
type SourcesReadyFn func() bool
// Wait for the container runtime to be up with a timeout.
func waitUntilRuntimeIsUp(cr kubecontainer.Runtime, timeout time.Duration) error {
var err error = nil
waitStart := time.Now()
for time.Since(waitStart) < timeout {
_, err = cr.Version()
if err == nil {
return nil
}
time.Sleep(100 * time.Millisecond)
}
return err
}
// New creates a new Kubelet for use in main
func NewMainKubelet(
hostname string,
nodeName string,
dockerClient dockertools.DockerInterface,
kubeClient client.Interface,
rootDirectory string,
podInfraContainerImage string,
resyncInterval time.Duration,
pullQPS float32,
pullBurst int,
eventQPS float32,
eventBurst int,
containerGCPolicy ContainerGCPolicy,
sourcesReady SourcesReadyFn,
registerNode bool,
standaloneMode bool,
clusterDomain string,
clusterDNS net.IP,
masterServiceNamespace string,
volumePlugins []volume.VolumePlugin,
networkPlugins []network.NetworkPlugin,
networkPluginName string,
streamingConnectionIdleTimeout time.Duration,
recorder record.EventRecorder,
cadvisorInterface cadvisor.Interface,
imageGCPolicy ImageGCPolicy,
diskSpacePolicy DiskSpacePolicy,
cloud cloudprovider.Interface,
nodeStatusUpdateFrequency time.Duration,
resourceContainer string,
osInterface kubecontainer.OSInterface,
cgroupRoot string,
containerRuntime string,
rktPath string,
rktStage1Image string,
mounter mount.Interface,
writer kubeio.Writer,
dockerDaemonContainer string,
systemContainer string,
configureCBR0 bool,
podCIDR string,
pods int,
dockerExecHandler dockertools.ExecHandler,
resolverConfig string,
cpuCFSQuota bool,
daemonEndpoints *api.NodeDaemonEndpoints,
serializeImagePulls bool,
) (*Kubelet, error) {
if rootDirectory == "" {
return nil, fmt.Errorf("invalid root directory %q", rootDirectory)
}
if resyncInterval <= 0 {
return nil, fmt.Errorf("invalid sync frequency %d", resyncInterval)
}
if systemContainer != "" && cgroupRoot == "" {
return nil, fmt.Errorf("invalid configuration: system container was specified and cgroup root was not specified")
}
dockerClient = dockertools.NewInstrumentedDockerInterface(dockerClient)
serviceStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
if kubeClient != nil {
// TODO: cache.NewListWatchFromClient is limited as it takes a client implementation rather
// than an interface. There is no way to construct a list+watcher using resource name.
listWatch := &cache.ListWatch{
ListFunc: func() (runtime.Object, error) {
return kubeClient.Services(api.NamespaceAll).List(labels.Everything())
},
WatchFunc: func(resourceVersion string) (watch.Interface, error) {
return kubeClient.Services(api.NamespaceAll).Watch(labels.Everything(), fields.Everything(), resourceVersion)
},
}
cache.NewReflector(listWatch, &api.Service{}, serviceStore, 0).Run()
}
serviceLister := &cache.StoreToServiceLister{Store: serviceStore}
nodeStore := cache.NewStore(cache.MetaNamespaceKeyFunc)
if kubeClient != nil {
// TODO: cache.NewListWatchFromClient is limited as it takes a client implementation rather
// than an interface. There is no way to construct a list+watcher using resource name.
fieldSelector := fields.Set{client.ObjectNameField: nodeName}.AsSelector()
listWatch := &cache.ListWatch{
ListFunc: func() (runtime.Object, error) {
return kubeClient.Nodes().List(labels.Everything(), fieldSelector)
},
WatchFunc: func(resourceVersion string) (watch.Interface, error) {
return kubeClient.Nodes().Watch(labels.Everything(), fieldSelector, resourceVersion)
},
}
cache.NewReflector(listWatch, &api.Node{}, nodeStore, 0).Run()
}
nodeLister := &cache.StoreToNodeLister{Store: nodeStore}
// TODO: get the real node object of ourself,
// and use the real node name and UID.
// TODO: what is namespace for node?
nodeRef := &api.ObjectReference{
Kind: "Node",
Name: nodeName,
UID: types.UID(nodeName),
Namespace: "",
}
containerGC, err := newContainerGC(dockerClient, containerGCPolicy)
if err != nil {
return nil, err
}
imageManager, err := newImageManager(dockerClient, cadvisorInterface, recorder, nodeRef, imageGCPolicy)
if err != nil {
return nil, fmt.Errorf("failed to initialize image manager: %v", err)
}
diskSpaceManager, err := newDiskSpaceManager(cadvisorInterface, diskSpacePolicy)
if err != nil {
return nil, fmt.Errorf("failed to initialize disk manager: %v", err)
}
statusManager := status.NewManager(kubeClient)
readinessManager := kubecontainer.NewReadinessManager()
containerRefManager := kubecontainer.NewRefManager()
volumeManager := newVolumeManager()
oomWatcher := NewOOMWatcher(cadvisorInterface, recorder)
klet := &Kubelet{
hostname: hostname,
nodeName: nodeName,
dockerClient: dockerClient,
kubeClient: kubeClient,
rootDirectory: rootDirectory,
resyncInterval: resyncInterval,
containerRefManager: containerRefManager,
readinessManager: readinessManager,
httpClient: &http.Client{},
sourcesReady: sourcesReady,
registerNode: registerNode,
standaloneMode: standaloneMode,
clusterDomain: clusterDomain,
clusterDNS: clusterDNS,
serviceLister: serviceLister,
nodeLister: nodeLister,
runtimeMutex: sync.Mutex{},
runtimeUpThreshold: maxWaitForContainerRuntime,
lastTimestampRuntimeUp: time.Time{},
masterServiceNamespace: masterServiceNamespace,
streamingConnectionIdleTimeout: streamingConnectionIdleTimeout,
recorder: recorder,
cadvisor: cadvisorInterface,
containerGC: containerGC,
imageManager: imageManager,
diskSpaceManager: diskSpaceManager,
statusManager: statusManager,
volumeManager: volumeManager,
cloud: cloud,
nodeRef: nodeRef,
nodeStatusUpdateFrequency: nodeStatusUpdateFrequency,
resourceContainer: resourceContainer,
os: osInterface,
oomWatcher: oomWatcher,
cgroupRoot: cgroupRoot,
mounter: mounter,
writer: writer,
configureCBR0: configureCBR0,
podCIDR: podCIDR,
pods: pods,
syncLoopMonitor: util.AtomicValue{},
resolverConfig: resolverConfig,
cpuCFSQuota: cpuCFSQuota,
daemonEndpoints: daemonEndpoints,
}
if plug, err := network.InitNetworkPlugin(networkPlugins, networkPluginName, &networkHost{klet}); err != nil {
return nil, err
} else {
klet.networkPlugin = plug
}
machineInfo, err := klet.GetCachedMachineInfo()
if err != nil {
return nil, err
}
oomAdjuster := oom.NewOomAdjuster()
procFs := procfs.NewProcFs()
// Initialize the runtime.
switch containerRuntime {
case "docker":
// Only supported one for now, continue.
klet.containerRuntime = dockertools.NewDockerManager(
dockerClient,
recorder,
readinessManager,
containerRefManager,
machineInfo,
podInfraContainerImage,
pullQPS,
pullBurst,
containerLogsDir,
osInterface,
klet.networkPlugin,
klet,
klet.httpClient,
dockerExecHandler,
oomAdjuster,
procFs,
klet.cpuCFSQuota,
serializeImagePulls,
)
case "rkt":
conf := &rkt.Config{
Path: rktPath,
Stage1Image: rktStage1Image,
InsecureSkipVerify: true,
}
rktRuntime, err := rkt.New(
conf,
klet,
recorder,
containerRefManager,
readinessManager,
klet.volumeManager,
serializeImagePulls,
)
if err != nil {
return nil, err
}
klet.containerRuntime = rktRuntime
// No Docker daemon to put in a container.
dockerDaemonContainer = ""
default:
return nil, fmt.Errorf("unsupported container runtime %q specified", containerRuntime)
}
// Setup container manager, can fail if the devices hierarchy is not mounted
// (it is required by Docker however).
containerManager, err := newContainerManager(mounter, cadvisorInterface, dockerDaemonContainer, systemContainer, resourceContainer)
if err != nil {
return nil, fmt.Errorf("failed to create the Container Manager: %v", err)
}
klet.containerManager = containerManager
go util.Until(klet.syncNetworkStatus, 30*time.Second, util.NeverStop)
if klet.kubeClient != nil {
// Start syncing node status immediately, this may set up things the runtime needs to run.
go util.Until(klet.syncNodeStatus, klet.nodeStatusUpdateFrequency, util.NeverStop)
}
// Wait for the runtime to be up with a timeout.
if err := waitUntilRuntimeIsUp(klet.containerRuntime, maxWaitForContainerRuntime); err != nil {
return nil, fmt.Errorf("timed out waiting for %q to come up: %v", containerRuntime, err)
}
klet.lastTimestampRuntimeUp = time.Now()
klet.runner = klet.containerRuntime
klet.podManager = newBasicPodManager(klet.kubeClient)
runtimeCache, err := kubecontainer.NewRuntimeCache(klet.containerRuntime)
if err != nil {
return nil, err
}
klet.runtimeCache = runtimeCache
klet.podWorkers = newPodWorkers(runtimeCache, klet.syncPod, recorder)
metrics.Register(runtimeCache)
if err = klet.setupDataDirs(); err != nil {
return nil, err
}
if err = klet.volumePluginMgr.InitPlugins(volumePlugins, &volumeHost{klet}); err != nil {
return nil, err
}
// If the container logs directory does not exist, create it.
if _, err := os.Stat(containerLogsDir); err != nil {
if err := osInterface.Mkdir(containerLogsDir, 0755); err != nil {
glog.Errorf("Failed to create directory %q: %v", containerLogsDir, err)
}
}
klet.backOff = util.NewBackOff(resyncInterval, maxContainerBackOff)
klet.podKillingCh = make(chan *kubecontainer.Pod, podKillingChannelCapacity)
return klet, nil
}
type serviceLister interface {
List() (api.ServiceList, error)
}
type nodeLister interface {
List() (machines api.NodeList, err error)
GetNodeInfo(id string) (*api.Node, error)
}
// Kubelet is the main kubelet implementation.
type Kubelet struct {
hostname string
nodeName string
dockerClient dockertools.DockerInterface
runtimeCache kubecontainer.RuntimeCache
kubeClient client.Interface
rootDirectory string
podWorkers PodWorkers
resyncInterval time.Duration
resyncTicker *time.Ticker
sourcesReady SourcesReadyFn
podManager podManager
// Needed to report events for containers belonging to deleted/modified pods.
// Tracks references for reporting events
containerRefManager *kubecontainer.RefManager
// Optional, defaults to /logs/ from /var/log
logServer http.Handler
// Optional, defaults to simple Docker implementation
runner kubecontainer.ContainerCommandRunner
// Optional, client for http requests, defaults to empty client
httpClient kubeletTypes.HttpGetter
// cAdvisor used for container information.
cadvisor cadvisor.Interface
// Set to true to have the node register itself with the apiserver.
registerNode bool
// for internal book keeping; access only from within registerWithApiserver
registrationCompleted bool
// Set to true if the kubelet is in standalone mode (i.e. setup without an apiserver)
standaloneMode bool
// If non-empty, use this for container DNS search.
clusterDomain string
// If non-nil, use this for container DNS server.
clusterDNS net.IP
masterServiceNamespace string
serviceLister serviceLister
nodeLister nodeLister
// Last timestamp when runtime responded on ping.
// Mutex is used to protect this value.
runtimeMutex sync.Mutex
runtimeUpThreshold time.Duration
lastTimestampRuntimeUp time.Time
// Network Status information
networkConfigMutex sync.Mutex
networkConfigured bool
// Volume plugins.
volumePluginMgr volume.VolumePluginMgr
// Network plugin.
networkPlugin network.NetworkPlugin
// Container readiness state manager.
readinessManager *kubecontainer.ReadinessManager
// How long to keep idle streaming command execution/port forwarding
// connections open before terminating them
streamingConnectionIdleTimeout time.Duration
// The EventRecorder to use
recorder record.EventRecorder
// Policy for handling garbage collection of dead containers.
containerGC containerGC
// Manager for images.
imageManager imageManager
// Diskspace manager.
diskSpaceManager diskSpaceManager
// Cached MachineInfo returned by cadvisor.
machineInfo *cadvisorApi.MachineInfo
// Syncs pods statuses with apiserver; also used as a cache of statuses.
statusManager status.Manager
// Manager for the volume maps for the pods.
volumeManager *volumeManager
//Cloud provider interface
cloud cloudprovider.Interface
// Reference to this node.
nodeRef *api.ObjectReference
// Container runtime.
containerRuntime kubecontainer.Runtime
// nodeStatusUpdateFrequency specifies how often kubelet posts node status to master.
// Note: be cautious when changing the constant, it must work with nodeMonitorGracePeriod
// in nodecontroller. There are several constraints:
// 1. nodeMonitorGracePeriod must be N times more than nodeStatusUpdateFrequency, where
// N means number of retries allowed for kubelet to post node status. It is pointless
// to make nodeMonitorGracePeriod be less than nodeStatusUpdateFrequency, since there
// will only be fresh values from Kubelet at an interval of nodeStatusUpdateFrequency.
// The constant must be less than podEvictionTimeout.
// 2. nodeStatusUpdateFrequency needs to be large enough for kubelet to generate node
// status. Kubelet may fail to update node status reliably if the value is too small,
// as it takes time to gather all necessary node information.
nodeStatusUpdateFrequency time.Duration
// The name of the resource-only container to run the Kubelet in (empty for no container).
// Name must be absolute.
resourceContainer string
os kubecontainer.OSInterface
// Watcher of out of memory events.
oomWatcher OOMWatcher
// If non-empty, pass this to the container runtime as the root cgroup.
cgroupRoot string
// Mounter to use for volumes.
mounter mount.Interface
// Writer interface to use for volumes.
writer kubeio.Writer
// Manager of non-Runtime containers.
containerManager containerManager
// Whether or not kubelet should take responsibility for keeping cbr0 in
// the correct state.
configureCBR0 bool
podCIDR string
// Number of Pods which can be run by this Kubelet
pods int
// Monitor Kubelet's sync loop
syncLoopMonitor util.AtomicValue
// Container restart Backoff
backOff *util.Backoff
// Channel for sending pods to kill.
podKillingCh chan *kubecontainer.Pod
// The configuration file used as the base to generate the container's
// DNS resolver configuration file. This can be used in conjunction with
// clusterDomain and clusterDNS.
resolverConfig string
// Optionally shape the bandwidth of a pod
shaper bandwidth.BandwidthShaper
// True if container cpu limits should be enforced via cgroup CFS quota
cpuCFSQuota bool
// Information about the ports which are opened by daemons on Node running this Kubelet server.
daemonEndpoints *api.NodeDaemonEndpoints
}
// getRootDir returns the full path to the directory under which kubelet can
// store data. These functions are useful to pass interfaces to other modules
// that may need to know where to write data without getting a whole kubelet
// instance.
func (kl *Kubelet) getRootDir() string {
return kl.rootDirectory
}
// getPodsDir returns the full path to the directory under which pod
// directories are created.
func (kl *Kubelet) getPodsDir() string {
return path.Join(kl.getRootDir(), "pods")
}
// getPluginsDir returns the full path to the directory under which plugin
// directories are created. Plugins can use these directories for data that
// they need to persist. Plugins should create subdirectories under this named
// after their own names.
func (kl *Kubelet) getPluginsDir() string {
return path.Join(kl.getRootDir(), "plugins")
}
// getPluginDir returns a data directory name for a given plugin name.
// Plugins can use these directories to store data that they need to persist.
// For per-pod plugin data, see getPodPluginDir.
func (kl *Kubelet) getPluginDir(pluginName string) string {
return path.Join(kl.getPluginsDir(), pluginName)
}
// getPodDir returns the full path to the per-pod data directory for the
// specified pod. This directory may not exist if the pod does not exist.
func (kl *Kubelet) getPodDir(podUID types.UID) string {
// Backwards compat. The "old" stuff should be removed before 1.0
// release. The thinking here is this:
// !old && !new = use new
// !old && new = use new
// old && !new = use old
// old && new = use new (but warn)
oldPath := path.Join(kl.getRootDir(), string(podUID))
oldExists := dirExists(oldPath)
newPath := path.Join(kl.getPodsDir(), string(podUID))
newExists := dirExists(newPath)
if oldExists && !newExists {
return oldPath
}
if oldExists {
glog.Warningf("Data dir for pod %q exists in both old and new form, using new", podUID)
}
return newPath
}
// getPodVolumesDir returns the full path to the per-pod data directory under
// which volumes are created for the specified pod. This directory may not
// exist if the pod does not exist.
func (kl *Kubelet) getPodVolumesDir(podUID types.UID) string {
return path.Join(kl.getPodDir(podUID), "volumes")
}
// getPodVolumeDir returns the full path to the directory which represents the
// named volume under the named plugin for specified pod. This directory may not
// exist if the pod does not exist.
func (kl *Kubelet) getPodVolumeDir(podUID types.UID, pluginName string, volumeName string) string {
return path.Join(kl.getPodVolumesDir(podUID), pluginName, volumeName)
}
// getPodPluginsDir returns the full path to the per-pod data directory under
// which plugins may store data for the specified pod. This directory may not
// exist if the pod does not exist.
func (kl *Kubelet) getPodPluginsDir(podUID types.UID) string {
return path.Join(kl.getPodDir(podUID), "plugins")
}
// getPodPluginDir returns a data directory name for a given plugin name for a
// given pod UID. Plugins can use these directories to store data that they
// need to persist. For non-per-pod plugin data, see getPluginDir.
func (kl *Kubelet) getPodPluginDir(podUID types.UID, pluginName string) string {
return path.Join(kl.getPodPluginsDir(podUID), pluginName)
}
// getPodContainerDir returns the full path to the per-pod data directory under
// which container data is held for the specified pod. This directory may not
// exist if the pod or container does not exist.
func (kl *Kubelet) getPodContainerDir(podUID types.UID, ctrName string) string {
// Backwards compat. The "old" stuff should be removed before 1.0
// release. The thinking here is this:
// !old && !new = use new
// !old && new = use new
// old && !new = use old
// old && new = use new (but warn)
oldPath := path.Join(kl.getPodDir(podUID), ctrName)
oldExists := dirExists(oldPath)
newPath := path.Join(kl.getPodDir(podUID), "containers", ctrName)
newExists := dirExists(newPath)
if oldExists && !newExists {
return oldPath
}
if oldExists {
glog.Warningf("Data dir for pod %q, container %q exists in both old and new form, using new", podUID, ctrName)
}
return newPath
}
func dirExists(path string) bool {
s, err := os.Stat(path)
if err != nil {
return false
}
return s.IsDir()
}
func (kl *Kubelet) setupDataDirs() error {
kl.rootDirectory = path.Clean(kl.rootDirectory)
if err := os.MkdirAll(kl.getRootDir(), 0750); err != nil {
return fmt.Errorf("error creating root directory: %v", err)
}
if err := os.MkdirAll(kl.getPodsDir(), 0750); err != nil {
return fmt.Errorf("error creating pods directory: %v", err)
}
if err := os.MkdirAll(kl.getPluginsDir(), 0750); err != nil {
return fmt.Errorf("error creating plugins directory: %v", err)
}
return nil
}
// Get a list of pods that have data directories.
func (kl *Kubelet) listPodsFromDisk() ([]types.UID, error) {
podInfos, err := ioutil.ReadDir(kl.getPodsDir())
if err != nil {
return nil, err
}
pods := []types.UID{}
for i := range podInfos {
if podInfos[i].IsDir() {
pods = append(pods, types.UID(podInfos[i].Name()))
}
}
return pods, nil
}
func (kl *Kubelet) GetNode() (*api.Node, error) {
if kl.standaloneMode {
return nil, errors.New("no node entry for kubelet in standalone mode")
}
return kl.nodeLister.GetNodeInfo(kl.nodeName)
}
// Starts garbage collection threads.
func (kl *Kubelet) StartGarbageCollection() {
go util.Until(func() {
if err := kl.containerGC.GarbageCollect(); err != nil {
glog.Errorf("Container garbage collection failed: %v", err)
}
}, time.Minute, util.NeverStop)
go util.Until(func() {
if err := kl.imageManager.GarbageCollect(); err != nil {
glog.Errorf("Image garbage collection failed: %v", err)
}
}, 5*time.Minute, util.NeverStop)
}
// Run starts the kubelet reacting to config updates
func (kl *Kubelet) Run(updates <-chan PodUpdate) {
if kl.logServer == nil {
kl.logServer = http.StripPrefix("/logs/", http.FileServer(http.Dir("/var/log/")))
}
if kl.kubeClient == nil {
glog.Warning("No api server defined - no node status update will be sent.")
}
// Move Kubelet to a container.
if kl.resourceContainer != "" {
// Fixme: I need to reside inside ContainerManager interface.
err := util.RunInResourceContainer(kl.resourceContainer)
if err != nil {
glog.Warningf("Failed to move Kubelet to container %q: %v", kl.resourceContainer, err)
}
glog.Infof("Running in container %q", kl.resourceContainer)
}
if err := kl.imageManager.Start(); err != nil {
kl.recorder.Eventf(kl.nodeRef, "KubeletSetupFailed", "Failed to start ImageManager %v", err)
glog.Errorf("Failed to start ImageManager, images may not be garbage collected: %v", err)
}
if err := kl.cadvisor.Start(); err != nil {
kl.recorder.Eventf(kl.nodeRef, "KubeletSetupFailed", "Failed to start CAdvisor %v", err)
glog.Errorf("Failed to start CAdvisor, system may not be properly monitored: %v", err)
}
if err := kl.containerManager.Start(); err != nil {
kl.recorder.Eventf(kl.nodeRef, "KubeletSetupFailed", "Failed to start ContainerManager %v", err)
glog.Errorf("Failed to start ContainerManager, system may not be properly isolated: %v", err)
}
if err := kl.oomWatcher.Start(kl.nodeRef); err != nil {
kl.recorder.Eventf(kl.nodeRef, "KubeletSetupFailed", "Failed to start OOM watcher %v", err)
glog.Errorf("Failed to start OOM watching: %v", err)
}
go util.Until(kl.updateRuntimeUp, 5*time.Second, util.NeverStop)
// Start a goroutine responsible for killing pods (that are not properly
// handled by pod workers).
go util.Until(kl.podKiller, 1*time.Second, util.NeverStop)
// Run the system oom watcher forever.
kl.statusManager.Start()
kl.syncLoop(updates, kl)
}
func (kl *Kubelet) initialNodeStatus() (*api.Node, error) {
node := &api.Node{
ObjectMeta: api.ObjectMeta{
Name: kl.nodeName,
Labels: map[string]string{"kubernetes.io/hostname": kl.hostname},
},
}
if kl.cloud != nil {
instances, ok := kl.cloud.Instances()
if !ok {
return nil, fmt.Errorf("failed to get instances from cloud provider")
}
// TODO(roberthbailey): Can we do this without having credentials to talk
// to the cloud provider?
// TODO: ExternalID is deprecated, we'll have to drop this code
externalID, err := instances.ExternalID(kl.nodeName)
if err != nil {
return nil, fmt.Errorf("failed to get external ID from cloud provider: %v", err)
}
node.Spec.ExternalID = externalID
// TODO: We can't assume that the node has credentials to talk to the
// cloudprovider from arbitrary nodes. At most, we should talk to a
// local metadata server here.
node.Spec.ProviderID, err = cloudprovider.GetInstanceProviderID(kl.cloud, kl.nodeName)
if err != nil {
return nil, err
}
} else {
node.Spec.ExternalID = kl.hostname
}
if err := kl.setNodeStatus(node); err != nil {
return nil, err
}
return node, nil
}
// registerWithApiserver registers the node with the cluster master. It is safe
// to call multiple times, but not concurrently (kl.registrationCompleted is
// not locked).
func (kl *Kubelet) registerWithApiserver() {
if kl.registrationCompleted {
return
}
step := 100 * time.Millisecond
for {
time.Sleep(step)
step = step * 2
if step >= 7*time.Second {
step = 7 * time.Second
}
node, err := kl.initialNodeStatus()
if err != nil {
glog.Errorf("Unable to construct api.Node object for kubelet: %v", err)
continue
}
glog.V(2).Infof("Attempting to register node %s", node.Name)
if _, err := kl.kubeClient.Nodes().Create(node); err != nil {
if !apierrors.IsAlreadyExists(err) {
glog.V(2).Infof("Unable to register %s with the apiserver: %v", node.Name, err)
continue
}
currentNode, err := kl.kubeClient.Nodes().Get(kl.nodeName)
if err != nil {
glog.Errorf("error getting node %q: %v", kl.nodeName, err)
continue
}
if currentNode == nil {
glog.Errorf("no node instance returned for %q", kl.nodeName)
continue
}
if currentNode.Spec.ExternalID == node.Spec.ExternalID {
glog.Infof("Node %s was previously registered", node.Name)
kl.registrationCompleted = true
return
}
glog.Errorf(
"Previously %q had externalID %q; now it is %q; will delete and recreate.",
kl.nodeName, node.Spec.ExternalID, currentNode.Spec.ExternalID,
)
if err := kl.kubeClient.Nodes().Delete(node.Name); err != nil {
glog.Errorf("Unable to delete old node: %v", err)
} else {
glog.Errorf("Deleted old node object %q", kl.nodeName)
}
continue
}
glog.Infof("Successfully registered node %s", node.Name)
kl.registrationCompleted = true
return
}
}
// syncNodeStatus should be called periodically from a goroutine.
// It synchronizes node status to master, registering the kubelet first if
// necessary.
func (kl *Kubelet) syncNodeStatus() {
if kl.kubeClient == nil {
return
}
if kl.registerNode {
// This will exit immediately if it doesn't need to do anything.
kl.registerWithApiserver()
}
if err := kl.updateNodeStatus(); err != nil {
glog.Errorf("Unable to update node status: %v", err)
}
}
func makeMounts(pod *api.Pod, podDir string, container *api.Container, podVolumes kubecontainer.VolumeMap) ([]kubecontainer.Mount, error) {
// Kubernetes only mounts on /etc/hosts if :
// - container does not use hostNetwork and
// - container is not a infrastructure(pause) container
// - container is not already mounting on /etc/hosts
// When the pause container is being created, its IP is still unknown. Hence, PodIP will not have been set.
mountEtcHostsFile := !pod.Spec.HostNetwork && len(pod.Status.PodIP) > 0
glog.V(4).Infof("Will create hosts mount for container:%q, podIP:%s: %v", container.Name, pod.Status.PodIP, mountEtcHostsFile)
mounts := []kubecontainer.Mount{}
for _, mount := range container.VolumeMounts {
mountEtcHostsFile = mountEtcHostsFile && (mount.MountPath != etcHostsPath)
vol, ok := podVolumes[mount.Name]
if !ok {
glog.Warningf("Mount cannot be satisified for container %q, because the volume is missing: %q", container.Name, mount)
continue
}
mounts = append(mounts, kubecontainer.Mount{
Name: mount.Name,
ContainerPath: mount.MountPath,
HostPath: vol.GetPath(),
ReadOnly: mount.ReadOnly,
})
}
if mountEtcHostsFile {
hostsMount, err := makeHostsMount(podDir, pod.Status.PodIP, pod.Name)
if err != nil {
return nil, err
}
mounts = append(mounts, *hostsMount)
}
return mounts, nil
}
func makeHostsMount(podDir, podIP, podName string) (*kubecontainer.Mount, error) {
hostsFilePath := path.Join(podDir, "etc-hosts")
if err := ensureHostsFile(hostsFilePath, podIP, podName); err != nil {
return nil, err
}
return &kubecontainer.Mount{
Name: "k8s-managed-etc-hosts",
ContainerPath: etcHostsPath,
HostPath: hostsFilePath,
ReadOnly: false,
}, nil
}
func ensureHostsFile(fileName string, hostIP, hostName string) error {
if _, err := os.Stat(fileName); os.IsExist(err) {
glog.V(4).Infof("kubernetes-managed etc-hosts file exits. Will not be recreated: %q", fileName)
return nil
}
var buffer bytes.Buffer
buffer.WriteString("# Kubernetes-managed hosts file.\n")
buffer.WriteString("127.0.0.1\tlocalhost\n") // ipv4 localhost
buffer.WriteString("::1\tlocalhost ip6-localhost ip6-loopback\n") // ipv6 localhost
buffer.WriteString("fe00::0\tip6-localnet\n")
buffer.WriteString("fe00::0\tip6-mcastprefix\n")
buffer.WriteString("fe00::1\tip6-allnodes\n")
buffer.WriteString("fe00::2\tip6-allrouters\n")
buffer.WriteString(fmt.Sprintf("%s\t%s\n", hostIP, hostName))
return ioutil.WriteFile(fileName, buffer.Bytes(), 0644)
}
func makePortMappings(container *api.Container) (ports []kubecontainer.PortMapping) {
names := make(map[string]struct{})
for _, p := range container.Ports {
pm := kubecontainer.PortMapping{
HostPort: p.HostPort,
ContainerPort: p.ContainerPort,
Protocol: p.Protocol,
HostIP: p.HostIP,
}
// We need to create some default port name if it's not specified, since
// this is necessary for rkt.
// http://issue.k8s.io/7710
if p.Name == "" {
pm.Name = fmt.Sprintf("%s-%s:%d", container.Name, p.Protocol, p.ContainerPort)
} else {