core

Documentation

Overview

Package core provides definition for a generic interface that helps provision networking for an endpoint (like a container, a vm or a bare-metal host). The interface is invoked (north-bound) by the 'daemon' or the extension-plugin (TBD) part of docker. The interface in turn invokes (south-bound) a driver-interface that provides hardware/kernel/device specific programming implementation, if any.

Index

• func ErrIfKeyExists(err error) error
• type Address
• type Clustering
• type CommonState
• type Config
• type Driver
• type Endpoint
• type Error
  • func Errorf(f string, args ...interface{}) *Error
  • func (e *Error) Error() string
• type InstanceInfo
• type Network
• type NetworkDriver
• type Plugin
• type Resource
• type ResourceManager
• type ServiceInfo
• type State
• type StateDriver
• type WatchState
• type WatchableState

Functions

func ErrIfKeyExists

func ErrIfKeyExists(err error) error

ErrIfKeyExists checks if the error message contains "Key not found".

Types

type Address

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

Address is a string represenation of a network address (mac, ip, dns-name, url etc)

type Clustering

type Clustering interface {
	AddPeerHost(node ServiceInfo) error
	DeletePeerHost(node ServiceInfo) error
	AddMaster(node ServiceInfo) error
	DeleteMaster(node ServiceInfo) error
}

Clustering has functions for discovering peer nodes and masters

type CommonState

type CommonState struct {
	StateDriver StateDriver `json:"-"`
	ID          string      `json:"id"`
}

CommonState defines the fields common to all core.State implementations. This struct shall be embedded as anonymous field in all structs that implement core.State

type Config

type Config struct {
	V interface{}
}

Config object parsed from a json styled config

type Driver

type Driver interface{}

Driver implements the programming logic

type Endpoint

type Endpoint interface {
	CreateEndpoint(id string) error
	DeleteEndpoint(id string) error
	FetchEndpoint(id string) (State, error)
}

Endpoint identifies an addressable entity in a network. An endpoint belongs to a single network.

type Error

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

Error is our custom error with description, file, and line.

func Errorf

func Errorf(f string, args ...interface{}) *Error

Errorf returns an *Error based on the format specification provided.

func (*Error) Error

func (e *Error) Error() string

Error() allows *core.Error to present the `error` interface.

type InstanceInfo

type InstanceInfo struct {
	StateDriver StateDriver `json:"-"`
	HostLabel   string      `json:"host-label"`
	VtepIP      string      `json:"vtep-ip"`
	VlanIntf    string      `json:"vlan-if"`
}

InstanceInfo encapsulates data that is specific to a running instance of netplugin like label of host on which it is started.

type Network

type Network interface {
	CreateNetwork(id string) error
	DeleteNetwork(id, encap string, pktTag, extPktTag int) error
	FetchNetwork(id string) (State, error)
}

Network identifies a group of (addressable) endpoints that can comunicate.

type NetworkDriver

type NetworkDriver interface {
	Driver
	Init(config *Config, info *InstanceInfo) error
	Deinit()
	CreateNetwork(id string) error
	DeleteNetwork(id, encap string, pktTag, extPktTag int) error
	CreateEndpoint(id string) error
	DeleteEndpoint(id string) error
	AddPeerHost(node ServiceInfo) error
	DeletePeerHost(node ServiceInfo) error
	AddMaster(node ServiceInfo) error
	DeleteMaster(node ServiceInfo) error
}

NetworkDriver implements the programming logic for network and endpoints

type Plugin

type Plugin interface {
	Init(configStr string) error
	Deinit()
	Network
	Endpoint
	Clustering
}

Plugin brings together an implementation of a network, endpoint and state drivers. Along with implementing north-bound interfaces for network and endpoint operations

type Resource

type Resource interface {
	State
	Init(rsrcCfg interface{}) error
	Deinit()
	Description() string
	Allocate() (interface{}, error)
	Deallocate(interface{}) error
}

Resource defines a allocatable unit. A resource is uniquely identified by 'ID'. A resource description identifies the nature of the resource.

type ResourceManager

type ResourceManager interface {
	Init() error
	Deinit()
	DefineResource(id, desc string, rsrcCfg interface{}) error
	UndefineResource(id, desc string) error
	AllocateResourceVal(id, desc string) (interface{}, error)
	DeallocateResourceVal(id, desc string, value interface{}) error
}

ResourceManager provides mechanism to manage (define/undefine, allocate/deallocate) resources. Example, it may provide management in logically centralized manner in a distributed system

type ServiceInfo

type ServiceInfo struct {
	HostAddr string // Host name or IP address where its running
	Port     int    // Port number where its listening
}

ServiceInfo has information about a service

type State

type State interface {
	Read(id string) error
	ReadAll() ([]State, error)
	Write() error
	Clear() error
}

State identifies data uniquely identifiable by 'id' and stored in a (distributed) key-value store implemented by core.StateDriver.

type StateDriver

type StateDriver interface {
	Driver
	Init(config *Config) error
	Deinit()

	// XXX: the following raw versions of Read, Write, ReadAll and WatchAll
	// can perhaps be removed from core API, as no one uses them directly.
	Write(key string, value []byte) error
	Read(key string) ([]byte, error)
	ReadAll(baseKey string) ([][]byte, error)
	WatchAll(baseKey string, rsps chan [2][]byte) error

	WriteState(key string, value State,
		marshal func(interface{}) ([]byte, error)) error
	ReadState(key string, value State,
		unmarshal func([]byte, interface{}) error) error
	ReadAllState(baseKey string, stateType State,
		unmarshal func([]byte, interface{}) error) ([]State, error)
	// WatchAllState returns changes to a state from the point watch is started.
	// It's a blocking call.
	// XXX: This specification introduces a small time window where a few
	// updates might be missed that occurred just before watch was started.
	// May be watch shall return all existing state first and then subsequent
	// updates. Revisit if this enhancement is needed.
	WatchAllState(baseKey string, stateType State,
		unmarshal func([]byte, interface{}) error, rsps chan WatchState) error
	ClearState(key string) error
}

StateDriver provides the mechanism for reading/writing state for networks, endpoints and meta-data managed by the core. The state is assumed to be stored as key-value pairs with keys of type 'string' and value to be an opaque binary string, encoded/decoded by the logic specific to the high-level(consumer) interface.

type WatchState

type WatchState struct {
	Curr State
	Prev State
}

WatchState is used to provide a difference between core.State structs by providing both the current and previous state.

type WatchableState

type WatchableState interface {
	State
	WatchAll(rsps chan WatchState) error
}

WatchableState allows for the rest of core.State, plus the WatchAll call which allows the implementor to yield changes to a channel.