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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
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"os"
"path"
"path/filepath"
"sort"
"strings"
"sync"
"time"
"github.com/golang/glog"
cadvisorapi "github.com/google/cadvisor/info/v1"
cadvisorapiv2 "github.com/google/cadvisor/info/v2"
"k8s.io/kubernetes/pkg/api"
apierrors "k8s.io/kubernetes/pkg/api/errors"
utilpod "k8s.io/kubernetes/pkg/api/pod"
"k8s.io/kubernetes/pkg/api/resource"
"k8s.io/kubernetes/pkg/api/unversioned"
"k8s.io/kubernetes/pkg/api/validation"
"k8s.io/kubernetes/pkg/apis/componentconfig"
"k8s.io/kubernetes/pkg/client/cache"
clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
"k8s.io/kubernetes/pkg/client/record"
"k8s.io/kubernetes/pkg/cloudprovider"
"k8s.io/kubernetes/pkg/fieldpath"
"k8s.io/kubernetes/pkg/fields"
"k8s.io/kubernetes/pkg/kubelet/cadvisor"
"k8s.io/kubernetes/pkg/kubelet/cm"
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/pleg"
kubepod "k8s.io/kubernetes/pkg/kubelet/pod"
"k8s.io/kubernetes/pkg/kubelet/prober"
proberesults "k8s.io/kubernetes/pkg/kubelet/prober/results"
"k8s.io/kubernetes/pkg/kubelet/rkt"
"k8s.io/kubernetes/pkg/kubelet/server"
"k8s.io/kubernetes/pkg/kubelet/server/stats"
"k8s.io/kubernetes/pkg/kubelet/status"
kubetypes "k8s.io/kubernetes/pkg/kubelet/types"
"k8s.io/kubernetes/pkg/kubelet/util/format"
"k8s.io/kubernetes/pkg/kubelet/util/queue"
"k8s.io/kubernetes/pkg/runtime"
"k8s.io/kubernetes/pkg/securitycontext"
"k8s.io/kubernetes/pkg/types"
"k8s.io/kubernetes/pkg/util"
"k8s.io/kubernetes/pkg/util/atomic"
"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"
utilnet "k8s.io/kubernetes/pkg/util/net"
nodeutil "k8s.io/kubernetes/pkg/util/node"
"k8s.io/kubernetes/pkg/util/oom"
"k8s.io/kubernetes/pkg/util/procfs"
utilruntime "k8s.io/kubernetes/pkg/util/runtime"
"k8s.io/kubernetes/pkg/util/selinux"
"k8s.io/kubernetes/pkg/util/sets"
utilvalidation "k8s.io/kubernetes/pkg/util/validation"
"k8s.io/kubernetes/pkg/util/validation/field"
"k8s.io/kubernetes/pkg/util/wait"
"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, exported for the e2e test
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
// Period for performing global cleanup tasks.
housekeepingPeriod = time.Second * 2
etcHostsPath = "/etc/hosts"
// Capacity of the channel for receiving pod lifecycle events. This number
// is a bit arbitrary and may be adjusted in the future.
plegChannelCapacity = 1000
// Generic PLEG relies on relisting for discovering container events.
// A longer period means that kubelet will take longer to detect container
// changes and to update pod status. On the other hand, a shorter period
// will cause more frequent relisting (e.g., container runtime operations),
// leading to higher cpu usage.
// Note that even though we set the period to 1s, the relisting itself can
// take more than 1s to finish if the container runtime responds slowly
// and/or when there are many container changes in one cycle.
plegRelistPeriod = time.Second * 1
// backOffPeriod is the period to back off when pod syncing resulting in an
// error. It is also used as the base period for the exponential backoff
// container restarts and image pulls.
backOffPeriod = time.Second * 10
// Period for performing container garbage collection.
ContainerGCPeriod = time.Minute
// Period for performing image garbage collection.
ImageGCPeriod = 5 * time.Minute
)
// SyncHandler is an interface implemented by Kubelet, for testability
type SyncHandler interface {
HandlePodAdditions(pods []*api.Pod)
HandlePodUpdates(pods []*api.Pod)
HandlePodDeletions(pods []*api.Pod)
HandlePodReconcile(pods []*api.Pod)
HandlePodSyncs(pods []*api.Pod)
HandlePodCleanups() error
}
type SourcesReadyFn func(sourcesSeen sets.String) bool
// Option is a functional option type for Kubelet
type Option func(*Kubelet)
// New instantiates a new Kubelet object along with all the required internal modules.
// No initialization of Kubelet and its modules should happen here.
func NewMainKubelet(
hostname string,
nodeName string,
dockerClient dockertools.DockerInterface,
kubeClient clientset.Interface,
rootDirectory string,
podInfraContainerImage string,
resyncInterval time.Duration,
pullQPS float32,
pullBurst int,
eventQPS float32,
eventBurst int,
containerGCPolicy kubecontainer.ContainerGCPolicy,
sourcesReady SourcesReadyFn,
registerNode bool,
registerSchedulable 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,
nodeLabels map[string]string,
nodeStatusUpdateFrequency time.Duration,
osInterface kubecontainer.OSInterface,
cgroupRoot string,
containerRuntime string,
rktPath string,
rktStage1Image string,
mounter mount.Interface,
writer kubeio.Writer,
configureCBR0 bool,
nonMasqueradeCIDR string,
podCIDR string,
reconcileCIDR bool,
maxPods int,
dockerExecHandler dockertools.ExecHandler,
resolverConfig string,
cpuCFSQuota bool,
daemonEndpoints *api.NodeDaemonEndpoints,
oomAdjuster *oom.OOMAdjuster,
serializeImagePulls bool,
containerManager cm.ContainerManager,
outOfDiskTransitionFrequency time.Duration,
flannelExperimentalOverlay bool,
nodeIP net.IP,
reservation kubetypes.Reservation,
enableCustomMetrics bool,
volumeStatsAggPeriod time.Duration,
containerRuntimeOptions []kubecontainer.Option,
hairpinMode string,
babysitDaemons bool,
kubeOptions []Option,
) (*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)
}
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(options api.ListOptions) (runtime.Object, error) {
return kubeClient.Core().Services(api.NamespaceAll).List(options)
},
WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
return kubeClient.Core().Services(api.NamespaceAll).Watch(options)
},
}
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{api.ObjectNameField: nodeName}.AsSelector()
listWatch := &cache.ListWatch{
ListFunc: func(options api.ListOptions) (runtime.Object, error) {
options.FieldSelector = fieldSelector
return kubeClient.Core().Nodes().List(options)
},
WatchFunc: func(options api.ListOptions) (watch.Interface, error) {
options.FieldSelector = fieldSelector
return kubeClient.Core().Nodes().Watch(options)
},
}
cache.NewReflector(listWatch, &api.Node{}, nodeStore, 0).Run()
}
nodeLister := &cache.StoreToNodeLister{Store: nodeStore}
nodeInfo := &predicates.CachedNodeInfo{nodeLister}
// 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: "",
}
diskSpaceManager, err := newDiskSpaceManager(cadvisorInterface, diskSpacePolicy)
if err != nil {
return nil, fmt.Errorf("failed to initialize disk manager: %v", err)
}
containerRefManager := kubecontainer.NewRefManager()
volumeManager := newVolumeManager()
oomWatcher := NewOOMWatcher(cadvisorInterface, recorder)
// TODO: remove when internal cbr0 implementation gets removed in favor
// of the kubenet network plugin
if networkPluginName == "kubenet" {
configureCBR0 = false
flannelExperimentalOverlay = false
}
klet := &Kubelet{
hostname: hostname,
nodeName: nodeName,
dockerClient: dockerClient,
kubeClient: kubeClient,
rootDirectory: rootDirectory,
resyncInterval: resyncInterval,
containerRefManager: containerRefManager,
httpClient: &http.Client{},
sourcesReady: sourcesReady,
registerNode: registerNode,
registerSchedulable: registerSchedulable,
standaloneMode: standaloneMode,
clusterDomain: clusterDomain,
clusterDNS: clusterDNS,
serviceLister: serviceLister,
nodeLister: nodeLister,
nodeInfo: nodeInfo,
masterServiceNamespace: masterServiceNamespace,
streamingConnectionIdleTimeout: streamingConnectionIdleTimeout,
recorder: recorder,
cadvisor: cadvisorInterface,
diskSpaceManager: diskSpaceManager,
volumeManager: volumeManager,
cloud: cloud,
nodeRef: nodeRef,
nodeLabels: nodeLabels,
nodeStatusUpdateFrequency: nodeStatusUpdateFrequency,
os: osInterface,
oomWatcher: oomWatcher,
cgroupRoot: cgroupRoot,
mounter: mounter,
writer: writer,
configureCBR0: configureCBR0,
nonMasqueradeCIDR: nonMasqueradeCIDR,
reconcileCIDR: reconcileCIDR,
maxPods: maxPods,
syncLoopMonitor: atomic.Value{},
resolverConfig: resolverConfig,
cpuCFSQuota: cpuCFSQuota,
daemonEndpoints: daemonEndpoints,
containerManager: containerManager,
flannelExperimentalOverlay: flannelExperimentalOverlay,
flannelHelper: NewFlannelHelper(),
nodeIP: nodeIP,
clock: util.RealClock{},
outOfDiskTransitionFrequency: outOfDiskTransitionFrequency,
reservation: reservation,
enableCustomMetrics: enableCustomMetrics,
babysitDaemons: babysitDaemons,
}
// TODO: Factor out "StatsProvider" from Kubelet so we don't have a cyclic dependency
klet.resourceAnalyzer = stats.NewResourceAnalyzer(klet, volumeStatsAggPeriod)
if klet.flannelExperimentalOverlay {
glog.Infof("Flannel is in charge of podCIDR and overlay networking.")
}
if klet.nodeIP != nil {
if err := klet.validateNodeIP(); err != nil {
return nil, err
}
glog.Infof("Using node IP: %q", klet.nodeIP.String())
}
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
}
procFs := procfs.NewProcFS()
imageBackOff := util.NewBackOff(backOffPeriod, MaxContainerBackOff)
klet.livenessManager = proberesults.NewManager()
klet.podCache = kubecontainer.NewCache()
klet.podManager = kubepod.NewBasicPodManager(kubepod.NewBasicMirrorClient(klet.kubeClient))
if mode, err := effectiveHairpinMode(componentconfig.HairpinMode(hairpinMode), containerRuntime, configureCBR0); err != nil {
// This is a non-recoverable error. Returning it up the callstack will just
// lead to retries of the same failure, so just fail hard.
glog.Fatalf("Invalid hairpin mode: %v", err)
} else {
klet.hairpinMode = mode
}
glog.Infof("Hairpin mode set to %q", klet.hairpinMode)
// Initialize the runtime.
switch containerRuntime {
case "docker":
// Only supported one for now, continue.
klet.containerRuntime = dockertools.NewDockerManager(
dockerClient,
kubecontainer.FilterEventRecorder(recorder),
klet.livenessManager,
containerRefManager,
klet.podManager,
machineInfo,
podInfraContainerImage,
pullQPS,
pullBurst,
containerLogsDir,
osInterface,
klet.networkPlugin,
klet,
klet.httpClient,
dockerExecHandler,
oomAdjuster,
procFs,
klet.cpuCFSQuota,
imageBackOff,
serializeImagePulls,
enableCustomMetrics,
klet.hairpinMode == componentconfig.HairpinVeth,
containerRuntimeOptions...,
)
case "rkt":
// TODO: Include hairpin mode settings in rkt?
conf := &rkt.Config{
Path: rktPath,
Stage1Image: rktStage1Image,
InsecureOptions: "image,ondisk",
}
rktRuntime, err := rkt.New(
conf,
klet,
recorder,
containerRefManager,
klet.livenessManager,
klet.volumeManager,
imageBackOff,
serializeImagePulls,
)
if err != nil {
return nil, err
}
klet.containerRuntime = rktRuntime
default:
return nil, fmt.Errorf("unsupported container runtime %q specified", containerRuntime)
}
klet.pleg = pleg.NewGenericPLEG(klet.containerRuntime, plegChannelCapacity, plegRelistPeriod, klet.podCache, util.RealClock{})
klet.runtimeState = newRuntimeState(maxWaitForContainerRuntime, configureCBR0)
klet.updatePodCIDR(podCIDR)
// setup containerGC
containerGC, err := kubecontainer.NewContainerGC(klet.containerRuntime, containerGCPolicy)
if err != nil {
return nil, err
}
klet.containerGC = containerGC
// setup imageManager
imageManager, err := newImageManager(klet.containerRuntime, cadvisorInterface, recorder, nodeRef, imageGCPolicy)
if err != nil {
return nil, fmt.Errorf("failed to initialize image manager: %v", err)
}
klet.imageManager = imageManager
klet.runner = klet.containerRuntime
klet.statusManager = status.NewManager(kubeClient, klet.podManager)
klet.probeManager = prober.NewManager(
klet.statusManager,
klet.livenessManager,
klet.runner,
containerRefManager,
recorder)
if err := klet.volumePluginMgr.InitPlugins(volumePlugins, &volumeHost{klet}); err != nil {
return nil, err
}
runtimeCache, err := kubecontainer.NewRuntimeCache(klet.containerRuntime)
if err != nil {
return nil, err
}
klet.runtimeCache = runtimeCache
klet.reasonCache = NewReasonCache()
klet.workQueue = queue.NewBasicWorkQueue()
klet.podWorkers = newPodWorkers(klet.syncPod, recorder, klet.workQueue, klet.resyncInterval, backOffPeriod, klet.podCache)
klet.backOff = util.NewBackOff(backOffPeriod, MaxContainerBackOff)
klet.podKillingCh = make(chan *kubecontainer.PodPair, podKillingChannelCapacity)
klet.sourcesSeen = sets.NewString()
klet.setNodeStatusFuncs = klet.defaultNodeStatusFuncs()
// apply functional Option's
for _, opt := range kubeOptions {
opt(klet)
}
return klet, nil
}
func effectiveHairpinMode(hairpinMode componentconfig.HairpinMode, containerRuntime string, configureCBR0 bool) (componentconfig.HairpinMode, error) {
// The hairpin mode setting doesn't matter if:
// - We're not using a bridge network. This is hard to check because we might
// be using a plugin. It matters if --configure-cbr0=true, and we currently
// don't pipe it down to any plugins.
// - It's set to hairpin-veth for a container runtime that doesn't know how
// to set the hairpin flag on the veth's of containers. Currently the
// docker runtime is the only one that understands this.
// - It's set to "none".
if hairpinMode == componentconfig.PromiscuousBridge || hairpinMode == componentconfig.HairpinVeth {
// Only on docker.
if containerRuntime != "docker" {
glog.Warningf("Hairpin mode set to %q but container runtime is %q, ignoring", hairpinMode, containerRuntime)
return componentconfig.HairpinNone, nil
}
if hairpinMode == componentconfig.PromiscuousBridge && !configureCBR0 {
// This is not a valid combination. Users might be using the
// default values (from before the hairpin-mode flag existed) and we
// should keep the old behavior.
glog.Warningf("Hairpin mode set to %q but configureCBR0 is false, falling back to %q", hairpinMode, componentconfig.HairpinVeth)
return componentconfig.HairpinVeth, nil
}
} else if hairpinMode == componentconfig.HairpinNone {
if configureCBR0 {
glog.Warningf("Hairpin mode set to %q and configureCBR0 is true, this might result in loss of hairpin packets", hairpinMode)
}
} else {
return "", fmt.Errorf("unknown value: %q", hairpinMode)
}
return hairpinMode, nil
}
type serviceLister interface {
List() (api.ServiceList, error)
}
type nodeLister interface {
List() (machines api.NodeList, err error)
}
// Kubelet is the main kubelet implementation.
type Kubelet struct {
hostname string
nodeName string
dockerClient dockertools.DockerInterface
runtimeCache kubecontainer.RuntimeCache
kubeClient clientset.Interface
rootDirectory string
podWorkers PodWorkers
resyncInterval time.Duration
sourcesReady SourcesReadyFn
// sourcesSeen records the sources seen by kubelet. This set is not thread
// safe and should only be access by the main kubelet syncloop goroutine.
sourcesSeen sets.String
podManager kubepod.Manager
// 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 kubetypes.HttpGetter
// cAdvisor used for container information.
cadvisor cadvisor.Interface
// Set to true to have the node register itself with the apiserver.
registerNode bool
// Set to true to have the node register itself as schedulable.
registerSchedulable 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
nodeInfo predicates.NodeInfo
// a list of node labels to register
nodeLabels map[string]string
// Last timestamp when runtime responded on ping.
// Mutex is used to protect this value.
runtimeState *runtimeState
// Volume plugins.
volumePluginMgr volume.VolumePluginMgr
// Network plugin.
networkPlugin network.NetworkPlugin
// Handles container probing.
probeManager prober.Manager
// Manages container health check results.
livenessManager proberesults.Manager
// 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 kubecontainer.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
// reasonCache caches the failure reason of the last creation of all containers, which is
// used for generating ContainerStatus.
reasonCache *ReasonCache
// 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
// Generates pod events.
pleg pleg.PodLifecycleEventGenerator
// Store kubecontainer.PodStatus for all pods.
podCache kubecontainer.Cache
os kubecontainer.OSInterface
// Watcher of out of memory events.
oomWatcher OOMWatcher
// Monitor resource usage
resourceAnalyzer stats.ResourceAnalyzer
// 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 cm.ContainerManager
nodeConfig cm.NodeConfig
// Whether or not kubelet should take responsibility for keeping cbr0 in
// the correct state.
configureCBR0 bool
reconcileCIDR bool
// Traffic to IPs outside this range will use IP masquerade.
nonMasqueradeCIDR string
// Maximum Number of Pods which can be run by this Kubelet
maxPods int
// Monitor Kubelet's sync loop
syncLoopMonitor atomic.Value
// Container restart Backoff
backOff *util.Backoff
// Channel for sending pods to kill.
podKillingCh chan *kubecontainer.PodPair
// 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
// TODO: remove when kubenet plugin is ready
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
// A queue used to trigger pod workers.
workQueue queue.WorkQueue
// oneTimeInitializer is used to initialize modules that are dependent on the runtime to be up.
oneTimeInitializer sync.Once
flannelExperimentalOverlay bool
// TODO: Flannelhelper doesn't store any state, we can instantiate it
// on the fly if we're confident the dbus connetions it opens doesn't
// put the system under duress.
flannelHelper *FlannelHelper
// If non-nil, use this IP address for the node
nodeIP net.IP
// clock is an interface that provides time related functionality in a way that makes it
// easy to test the code.
clock util.Clock
// outOfDiskTransitionFrequency specifies the amount of time the kubelet has to be actually
// not out of disk before it can transition the node condition status from out-of-disk to
// not-out-of-disk. This prevents a pod that causes out-of-disk condition from repeatedly
// getting rescheduled onto the node.
outOfDiskTransitionFrequency time.Duration
// reservation specifies resources which are reserved for non-pod usage, including kubernetes and
// non-kubernetes system processes.
reservation kubetypes.Reservation
// support gathering custom metrics.
enableCustomMetrics bool
// How the Kubelet should setup hairpin NAT. Can take the values: "promiscuous-bridge"
// (make cbr0 promiscuous), "hairpin-veth" (set the hairpin flag on veth interfaces)
// or "none" (do nothing).
hairpinMode componentconfig.HairpinMode
// The node has babysitter process monitoring docker and kubelet
babysitDaemons bool
// handlers called during the tryUpdateNodeStatus cycle
setNodeStatusFuncs []func(*api.Node) error
}
// Validate given node IP belongs to the current host
func (kl *Kubelet) validateNodeIP() error {
if kl.nodeIP == nil {
return nil
}
// Honor IP limitations set in setNodeStatus()
if kl.nodeIP.IsLoopback() {
return fmt.Errorf("nodeIP can't be loopback address")
}
if kl.nodeIP.To4() == nil {
return fmt.Errorf("nodeIP must be IPv4 address")
}
addrs, err := net.InterfaceAddrs()
if err != nil {
return err
}
for _, addr := range addrs {
var ip net.IP
switch v := addr.(type) {
case *net.IPNet:
ip = v.IP
case *net.IPAddr:
ip = v.IP
}
if ip != nil && ip.Equal(kl.nodeIP) {
return nil
}
}
return fmt.Errorf("Node IP: %q not found in the host's network interfaces", kl.nodeIP.String())
}
func (kl *Kubelet) allSourcesReady() bool {
// Make a copy of the sourcesSeen list because it's not thread-safe.
return kl.sourcesReady(sets.NewString(kl.sourcesSeen.List()...))
}
func (kl *Kubelet) addSource(source string) {
kl.sourcesSeen.Insert(source)
}
// 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 kl.initialNodeStatus()
}
return kl.nodeInfo.GetNodeInfo(kl.nodeName)
}
// Starts garbage collection threads.
func (kl *Kubelet) StartGarbageCollection() {
go wait.Until(func() {
if err := kl.containerGC.GarbageCollect(); err != nil {
glog.Errorf("Container garbage collection failed: %v", err)
}
}, ContainerGCPeriod, wait.NeverStop)
go wait.Until(func() {
if err := kl.imageManager.GarbageCollect(); err != nil {
glog.Errorf("Image garbage collection failed: %v", err)
}
}, ImageGCPeriod, wait.NeverStop)
}
// initializeModules will initialize internal modules that do not require the container runtime to be up.
// Note that the modules here must not depend on modules that are not initialized here.
func (kl *Kubelet) initializeModules() error {
// Step 1: Promethues metrics.
metrics.Register(kl.runtimeCache)
// Step 2: Setup filesystem directories.
if err := kl.setupDataDirs(); err != nil {
return err
}
// Step 3: If the container logs directory does not exist, create it.
if _, err := os.Stat(containerLogsDir); err != nil {
if err := kl.os.Mkdir(containerLogsDir, 0755); err != nil {
glog.Errorf("Failed to create directory %q: %v", containerLogsDir, err)
}
}
// Step 4: Start the image manager.
if err := kl.imageManager.Start(); err != nil {
return fmt.Errorf("Failed to start ImageManager, images may not be garbage collected: %v", err)
}
// Step 5: Start container manager.
if err := kl.containerManager.Start(); err != nil {
return fmt.Errorf("Failed to start ContainerManager %v", err)
}
// Step 6: Start out of memory watcher.
if err := kl.oomWatcher.Start(kl.nodeRef); err != nil {
return fmt.Errorf("Failed to start OOM watcher %v", err)
}
// Step 7: Start resource analyzer
kl.resourceAnalyzer.Start()
return nil
}
// initializeRuntimeDependentModules will initialize internal modules that require the container runtime to be up.
func (kl *Kubelet) initializeRuntimeDependentModules() {