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

• func GetPodFullName(pod *Pod) string
• func ListenAndServeKubeletServer(host HostInterface, updates chan<- interface{}, address string, port uint)
• func ResolvePort(portReference util.IntOrString, container *api.Container) (int, error)
• func ValidatePod(pod *Pod) (errors []error)
• type CadvisorInterface
• type HostInterface
• type Kubelet
  • func NewIntegrationTestKubelet(hn string, dc dockertools.DockerInterface) *Kubelet
  • func NewMainKubelet(hn string, dc dockertools.DockerInterface, cc CadvisorInterface, ...) *Kubelet
  • func (kl *Kubelet) GetContainerInfo(podFullName, uuid, containerName string, req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
  • func (kl *Kubelet) GetMachineInfo() (*info.MachineInfo, error)
  • func (kl *Kubelet) GetPodInfo(podFullName, uuid string) (api.PodInfo, error)
  • func (kl *Kubelet) GetRootInfo(req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
  • func (kl *Kubelet) LogEvent(event *api.Event) error
  • func (kl *Kubelet) Run(updates <-chan PodUpdate)
  • func (kl *Kubelet) RunInContainer(podFullName, uuid, container string, cmd []string) ([]byte, error)
  • func (kl *Kubelet) ServeLogs(w http.ResponseWriter, req *http.Request)
  • func (kl *Kubelet) SyncPods(pods []Pod) error
• type Pod
• type PodOperation
• type PodUpdate
• type Server
  • func NewServer(host HostInterface, updates chan<- interface{}) Server
  • func (s *Server) InstallDefaultHandlers()
  • func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request)
• type SyncHandler

Functions

func GetPodFullName

func GetPodFullName(pod *Pod) string

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

func ListenAndServeKubeletServer

func ListenAndServeKubeletServer(host HostInterface, updates chan<- interface{}, address string, port uint)

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.

func ValidatePod

func ValidatePod(pod *Pod) (errors []error)

Types

type CadvisorInterface

type CadvisorInterface interface {
	ContainerInfo(name string, req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
	MachineInfo() (*info.MachineInfo, error)
}

CadvisorInterface is an abstract interface for testability. It abstracts the interface of "github.com/google/cadvisor/client".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)
	GetPodInfo(name, uuid string) (api.PodInfo, error)
	RunInContainer(name, uuid, container string, cmd []string) ([]byte, 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, 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,
	cc CadvisorInterface,
	ec tools.EtcdClient,
	rd string,
	ri time.Duration) *Kubelet

New creates a new Kubelet for use in main

func (*Kubelet) GetContainerInfo

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

GetContainerInfo returns stats (from Cadvisor) for a container.

func (*Kubelet) GetMachineInfo

func (kl *Kubelet) GetMachineInfo() (*info.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 *info.ContainerInfoRequest) (*info.ContainerInfo, error)

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

func (*Kubelet) LogEvent

func (kl *Kubelet) LogEvent(event *api.Event) error

LogEvent logs an event to the etcd backend.

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) ServeLogs

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

Returns logs of current machine.

func (*Kubelet) SyncPods

func (kl *Kubelet) SyncPods(pods []Pod) error

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

type Pod

type Pod struct {
	Namespace string
	Name      string
	Manifest  api.ContainerManifest
}

Pod represents the structure of a pod on the Kubelet, distinct from the apiserver representation of a Pod.

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 []Pod
	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 array and Op to SET.

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{}) Server

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

func (*Server) InstallDefaultHandlers

func (s *Server) InstallDefaultHandlers()

InstallDefaultHandlers registers the 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([]Pod) error
}

SyncHandler is an interface implemented by Kubelet, for testability