kubelet

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
• func GetPodFullName(pod *api.BoundPod) string
• func ListenAndServeKubeletServer(host HostInterface, updates chan<- interface{}, address net.IP, port uint, ...)
• func ResolvePort(portReference util.IntOrString, container *api.Container) (int, error)
• type ByCreated
  • func (a ByCreated) Len() int
  • func (a ByCreated) Less(i, j int) bool
  • func (a ByCreated) Swap(i, j int)
• type FlushWriter
  • func (fw *FlushWriter) Write(p []byte) (n int, err error)
• type HostInterface
• type Kubelet
  • func NewIntegrationTestKubelet(hn string, rd string, dc dockertools.DockerInterface) *Kubelet
  • func NewMainKubelet(hn string, dc dockertools.DockerInterface, ec tools.EtcdClient, rd string, ...) *Kubelet
  • func (kl *Kubelet) BirthCry()
  • func (kl *Kubelet) GarbageCollectContainers() error
  • func (kl *Kubelet) GetBoundPods() ([]api.BoundPod, error)
  • func (kl *Kubelet) GetCadvisorClient() cadvisorInterface
  • func (kl *Kubelet) GetContainerInfo(podFullName, uuid, containerName string, req *cadvisor.ContainerInfoRequest) (*cadvisor.ContainerInfo, error)
  • func (kl *Kubelet) GetKubeletContainerLogs(podFullName, containerName, tail string, follow bool, stdout, stderr io.Writer) error
  • func (kl *Kubelet) GetMachineInfo() (*cadvisor.MachineInfo, error)
  • func (kl *Kubelet) GetPodInfo(podFullName, uuid string) (api.PodInfo, error)
  • func (kl *Kubelet) GetRootInfo(req *cadvisor.ContainerInfoRequest) (*cadvisor.ContainerInfo, error)
  • func (kl *Kubelet) Run(updates <-chan PodUpdate)
  • func (kl *Kubelet) RunInContainer(podFullName, uuid, container string, cmd []string) ([]byte, error)
  • func (kl *Kubelet) RunOnce(updates <-chan PodUpdate) ([]RunPodResult, error)
  • func (kl *Kubelet) ServeLogs(w http.ResponseWriter, req *http.Request)
  • func (kl *Kubelet) SetCadvisorClient(c cadvisorInterface)
  • func (kl *Kubelet) SyncPods(pods []api.BoundPod) error
• type PodOperation
• type PodUpdate
• type RunPodResult
• type Server
  • func NewServer(host HostInterface, updates chan<- interface{}, enableDebuggingHandlers bool) Server
  • func (s *Server) InstallDebuggingHandlers()
  • func (s *Server) InstallDefaultHandlers()
  • func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request)
• type SyncHandler

Constants

const (
	RunOnceManifestDelay     = 1 * time.Second
	RunOnceMaxRetries        = 10
	RunOnceRetryDelay        = 1 * time.Second
	RunOnceRetryDelayBackoff = 2
)

const ConfigSourceAnnotationKey = "kubernetes/config.source"

const (
	NetworkContainerImage = "kubernetes/pause:latest"
)

Functions

func GetPodFullName

func GetPodFullName(pod *api.BoundPod) string

GetPodFullName returns a name that uniquely identifies a pod across all config sources.

func ListenAndServeKubeletServer

func ListenAndServeKubeletServer(host HostInterface, updates chan<- interface{}, address net.IP, port uint, enableDebuggingHandlers bool)

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

func ResolvePort

func ResolvePort(portReference util.IntOrString, container *api.Container) (int, error)

ResolvePort attempts to turn a IntOrString port reference into a concrete port number. If portReference has an int value, it is treated as a literal, and simply returns that value. If portReference is a string, an attempt is first made to parse it as an integer. If that fails, an attempt is made to find a port with the same name in the container spec. If a port with the same name is found, it's ContainerPort value is returned. If no matching port is found, an error is returned.

Types

type ByCreated

type ByCreated []*docker.Container

func (ByCreated) Len

func (a ByCreated) Len() int

func (ByCreated) Less

func (a ByCreated) Less(i, j int) bool

func (ByCreated) Swap

func (a ByCreated) Swap(i, j int)

type FlushWriter

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

FlushWriter provides wrapper for responseWriter with HTTP streaming capabilities

func (*FlushWriter) Write

func (fw *FlushWriter) Write(p []byte) (n int, err error)

Write is a FlushWriter implementation of the io.Writer that sends any buffered data to the client.

type HostInterface

type HostInterface interface {
	GetContainerInfo(podFullName, uuid, containerName string, req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
	GetRootInfo(req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
	GetMachineInfo() (*info.MachineInfo, error)
	GetBoundPods() ([]api.BoundPod, error)
	GetPodInfo(name, uuid string) (api.PodInfo, error)
	RunInContainer(name, uuid, container string, cmd []string) ([]byte, error)
	GetKubeletContainerLogs(podFullName, containerName, tail string, follow bool, stdout, stderr io.Writer) error
	ServeLogs(w http.ResponseWriter, req *http.Request)
}

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

type Kubelet

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

Kubelet is the main kubelet implementation.

func NewIntegrationTestKubelet

func NewIntegrationTestKubelet(hn string, rd string, dc dockertools.DockerInterface) *Kubelet

NewIntegrationTestKubelet creates a new Kubelet for use in integration tests. TODO: add more integration tests, and expand parameter list as needed.

func NewMainKubelet

func NewMainKubelet(
	hn string,
	dc dockertools.DockerInterface,
	ec tools.EtcdClient,
	rd string,
	ni string,
	ri time.Duration,
	pullQPS float32,
	pullBurst int,
	minimumGCAge time.Duration,
	maxContainerCount int) *Kubelet

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) GarbageCollectContainers

func (kl *Kubelet) GarbageCollectContainers() error

TODO: Also enforce a maximum total number of containers.

func (*Kubelet) GetBoundPods

func (kl *Kubelet) GetBoundPods() ([]api.BoundPod, error)

GetBoundPods returns all pods bound to the kubelet and their spec

func (*Kubelet) GetCadvisorClient

func (kl *Kubelet) GetCadvisorClient() cadvisorInterface

GetCadvisorClient gets the cadvisor client.

func (*Kubelet) GetContainerInfo

func (kl *Kubelet) GetContainerInfo(podFullName, uuid, containerName string, req *cadvisor.ContainerInfoRequest) (*cadvisor.ContainerInfo, error)

GetContainerInfo returns stats (from Cadvisor) for a container.

func (*Kubelet) GetKubeletContainerLogs

func (kl *Kubelet) GetKubeletContainerLogs(podFullName, containerName, tail string, follow bool, stdout, stderr io.Writer) error

GetKubeletContainerLogs returns logs from the container The second parameter of GetPodInfo and FindPodContainer methods represents pod UUID, which is allowed to be blank

func (*Kubelet) GetMachineInfo

func (kl *Kubelet) GetMachineInfo() (*cadvisor.MachineInfo, error)

func (*Kubelet) GetPodInfo

func (kl *Kubelet) GetPodInfo(podFullName, uuid string) (api.PodInfo, error)

GetPodInfo returns information from Docker about the containers in a pod

func (*Kubelet) GetRootInfo

func (kl *Kubelet) GetRootInfo(req *cadvisor.ContainerInfoRequest) (*cadvisor.ContainerInfo, error)

GetRootInfo returns stats (from Cadvisor) of current machine (root container).

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, uuid, container 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) SetCadvisorClient

func (kl *Kubelet) SetCadvisorClient(c cadvisorInterface)

SetCadvisorClient sets the cadvisor client in a thread-safe way.

func (*Kubelet) SyncPods

func (kl *Kubelet) SyncPods(pods []api.BoundPod) error

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

type PodOperation

type PodOperation int

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

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
)

type PodUpdate

type PodUpdate struct {
	Pods []api.BoundPod
	Op   PodOperation
}

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.

type RunPodResult

type RunPodResult struct {
	Pod *api.BoundPod
	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, updates chan<- interface{}, 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 SyncHandler

type SyncHandler interface {
	SyncPods([]api.BoundPod) error
}

SyncHandler is an interface implemented by Kubelet, for testability