kubelet

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Published: May 19, 2016 License: Apache-2.0 Imports: 89 Imported by: 0

Documentation

Overview

Package kubelet is the package that contains the libraries that drive the Kubelet binary. The kubelet is responsible for node level pod management. It runs on each worker in the cluster.

Index

Constants

View Source
const (

	// max backoff period, exported for the e2e test
	MaxContainerBackOff = 300 * time.Second

	// Period for performing container garbage collection.
	ContainerGCPeriod = time.Minute
	// Period for performing image garbage collection.
	ImageGCPeriod = 5 * time.Minute
)

Variables

This section is empty.

Functions

func GetPhase

func GetPhase(spec *api.PodSpec, info []api.ContainerStatus) api.PodPhase

GetPhase returns the phase of a pod given its container info. This func is exported to simplify integration with 3rd party kubelet integrations like kubernetes-mesos.

Types

type DiskSpacePolicy

type DiskSpacePolicy struct {
	// free disk space threshold for filesystem holding docker images.
	DockerFreeDiskMB int
	// free disk space threshold for root filesystem. Host volumes are created on root fs.
	RootFreeDiskMB int
}

type FlannelHelper

type FlannelHelper struct {
	// contains filtered or unexported fields
}

A Kubelet to flannel bridging helper.

func NewFlannelHelper

func NewFlannelHelper() *FlannelHelper

NewFlannelHelper creates a new flannel helper.

func (*FlannelHelper) Handshake

func (f *FlannelHelper) Handshake() (podCIDR string, err error)

Handshake waits for the flannel subnet file and installs a few IPTables rules, returning the pod CIDR allocated for this node.

type ImageGCPolicy

type ImageGCPolicy struct {
	// Any usage above this threshold will always trigger garbage collection.
	// This is the highest usage we will allow.
	HighThresholdPercent int

	// Any usage below this threshold will never trigger garbage collection.
	// This is the lowest threshold we will try to garbage collect to.
	LowThresholdPercent int

	// Minimum age at which a image can be garbage collected.
	MinAge time.Duration
}

A policy for garbage collecting images. Policy defines an allowed band in which garbage collection will be run.

type KillPodOptions

type KillPodOptions struct {
	// PodStatusFunc is the function to invoke to set pod status in response to a kill request.
	PodStatusFunc PodStatusFunc
	// PodTerminationGracePeriodSecondsOverride is optional override to use if a pod is being killed as part of kill operation.
	PodTerminationGracePeriodSecondsOverride *int64
}

KillPodOptions are options when performing a pod update whose update type is kill.

type Kubelet

type Kubelet struct {

	// TODO: think about moving this to be centralized in PodWorkers in follow-on.
	// the list of handlers to call during pod admission.
	lifecycle.PodAdmitHandlers

	// the list of handlers to call during pod sync loop.
	lifecycle.PodSyncLoopHandlers

	// the list of handlers to call during pod sync.
	lifecycle.PodSyncHandlers
	// contains filtered or unexported fields
}

Kubelet is the main kubelet implementation.

func NewMainKubelet

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,
	sourcesReadyFn config.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,
	rktAPIEndpoint string,
	rktStage1Image string,
	mounter mount.Interface,
	writer kubeio.Writer,
	configureCBR0 bool,
	nonMasqueradeCIDR string,
	podCIDR string,
	reconcileCIDR bool,
	maxPods int,
	nvidiaGPUs 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,
	evictionConfig eviction.Config,
	kubeOptions []Option,
) (*Kubelet, error)

NewMainKubelet instantiates a new Kubelet object along with all the required internal modules. No initialization of Kubelet and its modules should happen here.

func (*Kubelet) AttachContainer

func (kl *Kubelet) AttachContainer(podFullName string, podUID types.UID, containerName string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error

AttachContainer uses the container runtime to attach the given streams to the given container.

func (*Kubelet) BirthCry

func (kl *Kubelet) BirthCry()

BirthCry sends an event that the kubelet has started up.

func (*Kubelet) DockerImagesFsInfo

func (kl *Kubelet) DockerImagesFsInfo() (cadvisorapiv2.FsInfo, error)

DockerImagesFsInfo returns information about docker image fs usage from cadvisor.

func (*Kubelet) ExecInContainer

func (kl *Kubelet) ExecInContainer(podFullName string, podUID types.UID, containerName string, cmd []string, stdin io.Reader, stdout, stderr io.WriteCloser, tty bool) error

ExecInContainer executes a command in a container, connecting the supplied stdin/stdout/stderr to the command's IO streams.

func (*Kubelet) GeneratePodHostNameAndDomain

func (kl *Kubelet) GeneratePodHostNameAndDomain(pod *api.Pod) (string, string, error)

func (*Kubelet) GenerateRunContainerOptions

func (kl *Kubelet) GenerateRunContainerOptions(pod *api.Pod, container *api.Container, podIP string) (*kubecontainer.RunContainerOptions, error)

GenerateRunContainerOptions generates the RunContainerOptions, which can be used by the container runtime to set parameters for launching a container.

func (*Kubelet) GetCachedMachineInfo

func (kl *Kubelet) GetCachedMachineInfo() (*cadvisorapi.MachineInfo, error)

GetCachedMachineInfo assumes that the machine info can't change without a reboot

func (*Kubelet) GetClusterDNS

func (kl *Kubelet) GetClusterDNS(pod *api.Pod) ([]string, []string, error)

GetClusterDNS returns a list of the DNS servers and a list of the DNS search domains of the cluster.

func (*Kubelet) GetContainerInfo

func (kl *Kubelet) GetContainerInfo(podFullName string, podUID types.UID, containerName string, req *cadvisorapi.ContainerInfoRequest) (*cadvisorapi.ContainerInfo, error)

GetContainerInfo returns stats (from Cadvisor) for a container.

func (*Kubelet) GetContainerInfoV2

func (kl *Kubelet) GetContainerInfoV2(name string, options cadvisorapiv2.RequestOptions) (map[string]cadvisorapiv2.ContainerInfo, error)

GetContainerInfoV2 returns stats (from Cadvisor) for containers.

func (*Kubelet) GetHostIP

func (kl *Kubelet) GetHostIP() (net.IP, error)

Returns host IP or nil in case of error.

func (*Kubelet) GetHostname

func (kl *Kubelet) GetHostname() string

GetHostname Returns the hostname as the kubelet sees it.

func (*Kubelet) GetKubeletContainerLogs

func (kl *Kubelet) GetKubeletContainerLogs(podFullName, containerName string, logOptions *api.PodLogOptions, stdout, stderr io.Writer) error

GetKubeletContainerLogs returns logs from the container TODO: this method is returning logs of random container attempts, when it should be returning the most recent attempt or all of them.

func (*Kubelet) GetNode

func (kl *Kubelet) GetNode() (*api.Node, error)

GetNode returns the node info for the configured node name of this Kubelet.

func (*Kubelet) GetNodeConfig

func (kl *Kubelet) GetNodeConfig() cm.NodeConfig

GetNodeConfig returns the container manager node config.

func (*Kubelet) GetPodByFullName

func (kl *Kubelet) GetPodByFullName(podFullName string) (*api.Pod, bool)

GetPodByFullName gets the pod with the given 'full' name, which incorporates the namespace as well as whether the pod was found.

func (*Kubelet) GetPodByName

func (kl *Kubelet) GetPodByName(namespace, name string) (*api.Pod, bool)

GetPodByName provides the first pod that matches namespace and name, as well as whether the pod was found.

func (*Kubelet) GetPodDir

func (kl *Kubelet) GetPodDir(podUID types.UID) string

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 (*Kubelet) GetPods

func (kl *Kubelet) GetPods() []*api.Pod

GetPods returns all pods bound to the kubelet and their spec, and the mirror pods.

func (*Kubelet) GetRawContainerInfo

func (kl *Kubelet) GetRawContainerInfo(containerName string, req *cadvisorapi.ContainerInfoRequest, subcontainers bool) (map[string]*cadvisorapi.ContainerInfo, error)

Returns stats (from Cadvisor) for a non-Kubernetes container.

func (*Kubelet) GetRunningPods

func (kl *Kubelet) GetRunningPods() ([]*api.Pod, error)

GetRunningPods returns all pods running on kubelet from looking at the container runtime cache. This function converts kubecontainer.Pod to api.Pod, so only the fields that exist in both kubecontainer.Pod and api.Pod are considered meaningful.

func (*Kubelet) GetRuntime

func (kl *Kubelet) GetRuntime() kubecontainer.Runtime

GetRuntime returns the current Runtime implementation in use by the kubelet. This func is exported to simplify integration with third party kubelet extensions (e.g. kubernetes-mesos).

func (*Kubelet) HandlePodAdditions

func (kl *Kubelet) HandlePodAdditions(pods []*api.Pod)

HandlePodAdditions is the callback in SyncHandler for pods being added from a config source.

func (*Kubelet) HandlePodCleanups

func (kl *Kubelet) HandlePodCleanups() error

HandlePodCleanups performs a series of cleanup work, including terminating pod workers, killing unwanted pods, and removing orphaned volumes/pod directories. TODO(yujuhong): This function is executed by the main sync loop, so it should not contain any blocking calls. Re-examine the function and decide whether or not we should move it into a separte goroutine.

func (*Kubelet) HandlePodDeletions

func (kl *Kubelet) HandlePodDeletions(pods []*api.Pod)

HandlePodDeletions is the callback in the SyncHandler interface for pods being deleted from a config source.

func (*Kubelet) HandlePodReconcile

func (kl *Kubelet) HandlePodReconcile(pods []*api.Pod)

HandlePodReconcile is the callback in the SyncHandler interface for pods that should be reconciled.

func (*Kubelet) HandlePodSyncs

func (kl *Kubelet) HandlePodSyncs(pods []*api.Pod)

HandlePodSyncs is the callback in the syncHandler interface for pods that should be dispatched to pod workers for sync.

func (*Kubelet) HandlePodUpdates

func (kl *Kubelet) HandlePodUpdates(pods []*api.Pod)

HandlePodUpdates is the callback in the SyncHandler interface for pods being updated from a config source.

func (*Kubelet) LatestLoopEntryTime

func (kl *Kubelet) LatestLoopEntryTime() time.Time

LatestLoopEntryTime returns the last time in the sync loop monitor.

func (*Kubelet) ListVolumesForPod

func (kl *Kubelet) ListVolumesForPod(podUID types.UID) (map[string]volume.Volume, bool)

ListVolumesForPod returns a map of the volumes associated with the given pod

func (*Kubelet) ListenAndServe

func (kl *Kubelet) ListenAndServe(address net.IP, port uint, tlsOptions *server.TLSOptions, auth server.AuthInterface, enableDebuggingHandlers bool)

ListenAndServe runs the kubelet HTTP server.

func (*Kubelet) ListenAndServeReadOnly

func (kl *Kubelet) ListenAndServeReadOnly(address net.IP, port uint)

ListenAndServeReadOnly runs the kubelet HTTP server in read-only mode.

func (*Kubelet) PLEGHealthCheck

func (kl *Kubelet) PLEGHealthCheck() (bool, error)

PLEGHealthCheck returns whether the PLEG is healty.

func (*Kubelet) PortForward

func (kl *Kubelet) PortForward(podFullName string, podUID types.UID, port uint16, stream io.ReadWriteCloser) error

PortForward connects to the pod's port and copies data between the port and the stream.

func (*Kubelet) ResyncInterval

func (kl *Kubelet) ResyncInterval() time.Duration

ResyncInterval returns the interval used for periodic syncs.

func (*Kubelet) RootFsInfo

func (kl *Kubelet) RootFsInfo() (cadvisorapiv2.FsInfo, error)

RootFsInfo returns info about the root fs from cadvisor.

func (*Kubelet) Run

func (kl *Kubelet) Run(updates <-chan kubetypes.PodUpdate)

Run starts the kubelet reacting to config updates

func (*Kubelet) RunInContainer

func (kl *Kubelet) RunInContainer(podFullName string, podUID types.UID, containerName string, cmd []string) ([]byte, error)

Run a command in a container, returns the combined stdout, stderr as an array of bytes

func (*Kubelet) RunOnce

func (kl *Kubelet) RunOnce(updates <-chan kubetypes.PodUpdate) ([]RunPodResult, error)

RunOnce polls from one configuration update and run the associated pods.

func (*Kubelet) ServeLogs

func (kl *Kubelet) ServeLogs(w http.ResponseWriter, req *http.Request)

Returns logs of current machine.

func (*Kubelet) StartGarbageCollection

func (kl *Kubelet) StartGarbageCollection()

Starts garbage collection threads.

func (*Kubelet) StreamingConnectionIdleTimeout

func (kl *Kubelet) StreamingConnectionIdleTimeout() time.Duration

StreamingConnectionIdleTimeout returns the timeout for streaming connections to the HTTP server.

type OOMWatcher

type OOMWatcher interface {
	Start(ref *api.ObjectReference) error
}

func NewOOMWatcher

func NewOOMWatcher(cadvisor cadvisor.Interface, recorder record.EventRecorder) OOMWatcher

type OnCompleteFunc

type OnCompleteFunc func(err error)

OnCompleteFunc is a function that is invoked when an operation completes. If err is non-nil, the operation did not complete successfully.

type Option

type Option func(*Kubelet)

Option is a functional option type for Kubelet

func SetNodeStatus

func SetNodeStatus(f func(*api.Node) error) Option

SetNodeStatus returns a functional Option that adds the given node status update handler to the Kubelet

type PodStatusFunc

type PodStatusFunc func(pod *api.Pod, podStatus *kubecontainer.PodStatus) api.PodStatus

PodStatusFunc is a function that is invoked to generate a pod status.

type PodWorkers

type PodWorkers interface {
	UpdatePod(options *UpdatePodOptions)
	ForgetNonExistingPodWorkers(desiredPods map[types.UID]empty)
	ForgetWorker(uid types.UID)
}

PodWorkers is an abstract interface for testability.

type ReasonCache

type ReasonCache struct {
	// contains filtered or unexported fields
}

ReasonCache stores the failure reason of the latest container start in a string, keyed by <pod_UID>_<container_name>. The goal is to propagate this reason to the container status. This endeavor is "best-effort" for two reasons:

  1. The cache is not persisted.
  2. We use an LRU cache to avoid extra garbage collection work. This means that some entries may be recycled before a pod has been deleted.

TODO(random-liu): Use more reliable cache which could collect garbage of failed pod. TODO(random-liu): Move reason cache to somewhere better.

func NewReasonCache

func NewReasonCache() *ReasonCache

func (*ReasonCache) Get

func (c *ReasonCache) Get(uid types.UID, name string) (error, string, bool)

Get gets error reason from the cache. The return values are error reason, error message and whether an error reason is found in the cache. If no error reason is found, empty string will be returned for error reason and error message.

func (*ReasonCache) Remove

func (c *ReasonCache) Remove(uid types.UID, name string)

Remove removes error reason from the cache

func (*ReasonCache) Update

func (c *ReasonCache) Update(uid types.UID, result kubecontainer.PodSyncResult)

Update updates the reason cache with the SyncPodResult. Only SyncResult with StartContainer action will change the cache.

type RunPodResult

type RunPodResult struct {
	Pod *api.Pod
	Err error
}

type SyncHandler

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
}

SyncHandler is an interface implemented by Kubelet, for testability

type UpdatePodOptions

type UpdatePodOptions struct {
	// pod to update
	Pod *api.Pod
	// the mirror pod for the pod to update, if it is a static pod
	MirrorPod *api.Pod
	// the type of update (create, update, sync, kill)
	UpdateType kubetypes.SyncPodType
	// optional callback function when operation completes
	// this callback is not guaranteed to be completed since a pod worker may
	// drop update requests if it was fulfilling a previous request.  this is
	// only guaranteed to be invoked in response to a kill pod request which is
	// always delivered.
	OnCompleteFunc OnCompleteFunc
	// if update type is kill, use the specified options to kill the pod.
	KillPodOptions *KillPodOptions
}

UpdatePodOptions is an options struct to pass to a UpdatePod operation.

Directories

Path Synopsis
api
Kubelet interactions with cAdvisor.
Kubelet interactions with cAdvisor.
Reads the pod configuration from the Kubernetes apiserver.
Reads the pod configuration from the Kubernetes apiserver.
Package custommetrics contains support for instrumenting cAdvisor to gather custom metrics from pods.
Package custommetrics contains support for instrumenting cAdvisor to gather custom metrics from pods.
Package envvars is the package that build the environment variables that kubernetes provides to the containers run by it.
Package envvars is the package that build the environment variables that kubernetes provides to the containers run by it.
Package eviction is responsible for enforcing eviction thresholds to maintain node stability.
Package eviction is responsible for enforcing eviction thresholds to maintain node stability.
Package leaky holds bits of kubelet that should be internal but have leaked out through bad abstractions.
Package leaky holds bits of kubelet that should be internal but have leaked out through bad abstractions.
Handlers for pod lifecycle events and interfaces to integrate with kubelet admission, synchronization, and eviction of pods.
Handlers for pod lifecycle events and interfaces to integrate with kubelet admission, synchronization, and eviction of pods.
cni
exec
Package exec scans and loads networking plugins that are installed under /usr/libexec/kubernetes/kubelet-plugins/net/exec/ The layout convention for a plugin is: plugin-name/ (plugins have to be directories first) plugin-name/plugin-name (executable that will be called out, see Vendoring Note for more nuances) plugin-name/<other-files> where, 'executable' has the following requirements: - should have exec permissions - should give non-zero exit code on failure, and zero on success - the arguments will be <action> <pod_namespace> <pod_name> <docker_id_of_infra_container> whereupon, <action> will be one of: - init, called when the kubelet loads the plugin - setup, called after the infra container of a pod is created, but before other containers of the pod are created - teardown, called before the pod infra container is killed - status, called at regular intervals and is supposed to return a json formatted output indicating the pod's IPAddress(v4/v6).
Package exec scans and loads networking plugins that are installed under /usr/libexec/kubernetes/kubelet-plugins/net/exec/ The layout convention for a plugin is: plugin-name/ (plugins have to be directories first) plugin-name/plugin-name (executable that will be called out, see Vendoring Note for more nuances) plugin-name/<other-files> where, 'executable' has the following requirements: - should have exec permissions - should give non-zero exit code on failure, and zero on success - the arguments will be <action> <pod_namespace> <pod_name> <docker_id_of_infra_container> whereupon, <action> will be one of: - init, called when the kubelet loads the plugin - setup, called after the infra container of a pod is created, but before other containers of the pod are created - teardown, called before the pod infra container is killed - status, called at regular intervals and is supposed to return a json formatted output indicating the pod's IPAddress(v4/v6).
Package pleg contains types and a generic implementation of the pod lifecycle event generator.
Package pleg contains types and a generic implementation of the pod lifecycle event generator.
pod
qos
package qos contains helper functions for quality of service.
package qos contains helper functions for quality of service.
rkt
Package rkt contains the Containerruntime interface implementation for rkt.
Package rkt contains the Containerruntime interface implementation for rkt.
Package server contains functions related to serving Kubelet's external interface.
Package server contains functions related to serving Kubelet's external interface.
portforward
package portforward contains server-side logic for handling port forwarding requests.
package portforward contains server-side logic for handling port forwarding requests.
remotecommand
package remotecommand contains functions related to executing commands in and attaching to pods.
package remotecommand contains functions related to executing commands in and attaching to pods.
stats
Package stats handles exporting Kubelet and container stats.
Package stats handles exporting Kubelet and container stats.
Common types in the Kubelet.
Common types in the Kubelet.
Utility functions.
Utility functions.

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