kubelet

package
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 Go to latest Published: Jun 9, 2015 License: Apache-2.0 Imports: 70 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 (
	RunOnceManifestDelay     = 1 * time.Second
	RunOnceMaxRetries        = 10
	RunOnceRetryDelay        = 1 * time.Second
	RunOnceRetryDelayBackoff = 2
)
View Source 
const (
	// This is the current pod configuration
	SET PodOperation = iota
	// Pods with the given ids are new to this source
	ADD
	// Pods with the given ids have been removed from this source
	REMOVE
	// Pods with the given ids have been updated in this source
	UPDATE

	// These constants identify the sources of pods
	// Updates from a file
	FileSource = "file"
	// Updates from querying a web page
	HTTPSource = "http"
	// Updates from Kubernetes API Server
	ApiserverSource = "api"
	// Updates from all sources
	AllSource = "*"

	// Used for ConfigMirrorAnnotationKey.
	MirrorType = "mirror"

	NamespaceDefault = api.NamespaceDefault
)
View Source 
const ConfigMirrorAnnotationKey = "kubernetes.io/config.mirror"
View Source 
const ConfigSourceAnnotationKey = "kubernetes.io/config.source"

Variables

View Source 
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")
)

Functions

func CapacityFromMachineInfo 

func CapacityFromMachineInfo(info *cadvisorApi.MachineInfo) api.ResourceList

func GetValidatedSources 

func GetValidatedSources(sources []string) ([]string, error)

Gets all validated sources from the specified sources.

func ListenAndServeKubeletReadOnlyServer 

func ListenAndServeKubeletReadOnlyServer(host HostInterface, address net.IP, port uint)

ListenAndServeKubeletReadOnlyServer initializes a server to respond to HTTP network requests on the Kubelet.

func ListenAndServeKubeletServer 

func ListenAndServeKubeletServer(host HostInterface, address net.IP, port uint, tlsOptions *TLSOptions, enableDebuggingHandlers bool)

ListenAndServeKubeletServer initializes a server to respond to HTTP network requests on the Kubelet.

Types

type ContainerGCPolicy 

type ContainerGCPolicy struct {
	// Minimum age at which a container can be garbage collected, zero for no limit.
	MinAge time.Duration

	// Max number of dead containers any single pod (UID, container name) pair is
	// allowed to have, less than zero for no limit.
	MaxPerPodContainer int

	// Max number of total dead containers, less than zero for no limit.
	MaxContainers int
}

Specified a policy for garbage collecting containers.

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 HostInterface 

type HostInterface interface {
	GetContainerInfo(podFullName string, uid types.UID, containerName string, req *cadvisorApi.ContainerInfoRequest) (*cadvisorApi.ContainerInfo, error)
	GetContainerRuntimeVersion() (kubecontainer.Version, error)
	GetRawContainerInfo(containerName string, req *cadvisorApi.ContainerInfoRequest, subcontainers bool) (map[string]*cadvisorApi.ContainerInfo, error)
	GetCachedMachineInfo() (*cadvisorApi.MachineInfo, error)
	GetPods() []*api.Pod
	GetPodByName(namespace, name string) (*api.Pod, bool)
	RunInContainer(name string, uid types.UID, container string, cmd []string) ([]byte, error)
	ExecInContainer(name string, uid types.UID, container string, cmd []string, in io.Reader, out, err io.WriteCloser, tty bool) error
	GetKubeletContainerLogs(podFullName, containerName, tail string, follow, previous bool, stdout, stderr io.Writer) error
	ServeLogs(w http.ResponseWriter, req *http.Request)
	PortForward(name string, uid types.UID, port uint16, stream io.ReadWriteCloser) error
	StreamingConnectionIdleTimeout() time.Duration
	GetHostname() string
}

HostInterface contains all the kubelet methods required by the server. For testablitiy.

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
}

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

type Kubelet 

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

Kubelet is the main kubelet implementation.

func NewMainKubelet 

func NewMainKubelet(
	hostname string,
	dockerClient dockertools.DockerInterface,
	kubeClient client.Interface,
	rootDirectory string,
	podInfraContainerImage string,
	resyncInterval time.Duration,
	pullQPS float32,
	pullBurst int,
	containerGCPolicy ContainerGCPolicy,
	sourcesReady SourcesReadyFn,
	registerNode 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,
	mounter mount.Interface,
	dockerDaemonContainer string,
	systemContainer string,
	configureCBR0 bool,
	pods int,
	dockerExecHandler dockertools.ExecHandler) (*Kubelet, error)

New creates a new Kubelet for use in main

func (*Kubelet) BirthCry 

func (kl *Kubelet) BirthCry()

BirthCry sends an event that the kubelet has started up.

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) GenerateRunContainerOptions 

func (kl *Kubelet) GenerateRunContainerOptions(pod *api.Pod, container *api.Container) (*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) 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) GetContainerRuntimeVersion 

func (kl *Kubelet) GetContainerRuntimeVersion() (kubecontainer.Version, error)

Returns the container runtime version for this Kubelet.

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, tail string, follow, previous bool, 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)

func (*Kubelet) GetPodByFullName 

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

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) 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) ListenAndServe 

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

func (*Kubelet) ListenAndServeReadOnly 

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

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) Run 

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

func (*Kubelet) StreamingConnectionIdleTimeout 

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

func (*Kubelet) SyncPods 

func (kl *Kubelet) SyncPods(allPods []*api.Pod, podSyncTypes map[types.UID]metrics.SyncPodType,
	mirrorPods map[string]*api.Pod, start time.Time) error

SyncPods synchronizes the configured list of pods (desired state) with the host current state.

type OOMWatcher 

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

func NewOOMWatcher 

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

type PodOperation 

type PodOperation int

PodOperation defines what changes will be made on a pod configuration.

type PodUpdate 

type PodUpdate struct {
	Pods   []*api.Pod
	Op     PodOperation
	Source string
}

PodUpdate defines an operation sent on the channel. You can add or remove single services by sending an array of size one and Op == ADD|REMOVE (with REMOVE, only the ID is required). For setting the state of the system to a given state for this source configuration, set Pods as desired and Op to SET, which will reset the system state to that specified in this operation for this source channel. To remove all pods, set Pods to empty object and Op to SET.

Additionally, Pods should never be nil - it should always point to an empty slice. While functionally similar, this helps our unit tests properly check that the correct PodUpdates are generated.

type PodWorkers 

type PodWorkers interface {
	UpdatePod(pod *api.Pod, mirrorPod *api.Pod, updateComplete func())
	ForgetNonExistingPodWorkers(desiredPods map[types.UID]empty)
}

PodWorkers is an abstract interface for testability.

type RunPodResult 

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

type Server 

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

Server is a http.Handler which exposes kubelet functionality over HTTP.

func NewServer 

func NewServer(host HostInterface, enableDebuggingHandlers bool) Server

NewServer initializes and configures a kubelet.Server object to handle HTTP requests.

func (*Server) InstallDebuggingHandlers 

func (s *Server) InstallDebuggingHandlers()

InstallDeguggingHandlers registers the HTTP request patterns that serve logs or run commands/containers

func (*Server) InstallDefaultHandlers 

func (s *Server) InstallDefaultHandlers()

InstallDefaultHandlers registers the default set of supported HTTP request patterns with the mux.

func (*Server) ServeHTTP 

func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request)

ServeHTTP responds to HTTP requests on the Kubelet.

type SourcesReadyFn 

type SourcesReadyFn func() bool

type StatsRequest 

type StatsRequest struct {
	// The name of the container for which to request stats.
	// Default: /
	ContainerName string `json:"containerName,omitempty"`

	// Max number of stats to return.
	// If start and end time are specified this limit is ignored.
	// Default: 60
	NumStats int `json:"num_stats,omitempty"`

	// Start time for which to query information.
	// If ommitted, the beginning of time is assumed.
	Start time.Time `json:"start,omitempty"`

	// End time for which to query information.
	// If ommitted, current time is assumed.
	End time.Time `json:"end,omitempty"`

	// Whether to also include information from subcontainers.
	// Default: false.
	Subcontainers bool `json:"subcontainers,omitempty"`
}

type SyncHandler 

type SyncHandler interface {

	// Syncs current state to match the specified pods. SyncPodType specified what
	// type of sync is occuring per pod. StartTime specifies the time at which
	// syncing began (for use in monitoring).
	SyncPods(pods []*api.Pod, podSyncTypes map[types.UID]metrics.SyncPodType, mirrorPods map[string]*api.Pod,
		startTime time.Time) error
}

SyncHandler is an interface implemented by Kubelet, for testability

type TLSOptions 

type TLSOptions struct {
	Config   *tls.Config
	CertFile string
	KeyFile  string
}

Source Files

View all Source files

Directories

Path Synopsis
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 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 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.
 Handlers for pod lifecycle events.
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 sucess - 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 As the executables are called, the file-descriptors stdin, stdout, stderr remain open.
 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 sucess - 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 As the executables are called, the file-descriptors stdin, stdout, stderr remain open.
Common types in the Kubelet.
 Common types in the Kubelet.

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