bridge

Documentation

Overview

Package bridge defines the bridge struct, which implements the control loop and functions of the GCS's bridge client.

Index

• type Bridge
  • func (b *Bridge) AssignHandlers(mux *Mux, gcs core.Core, host *hcsv2.Host)
  • func (b *Bridge) ListenAndServe(bridgeIn io.ReadCloser, bridgeOut io.WriteCloser) error
  • func (b *Bridge) PublishNotification(n *prot.ContainerNotification)
• type Handler
  • func UnknownMessageHandler() Handler
• type HandlerFunc
  • func (f HandlerFunc) ServeMsg(r *Request) (RequestResponse, error)
• type Mux
  • func NewBridgeMux() *Mux
  • func (mux *Mux) Handle(id prot.MessageIdentifier, ver prot.ProtocolVersion, handler Handler)
  • func (mux *Mux) HandleFunc(id prot.MessageIdentifier, ver prot.ProtocolVersion, ...)
  • func (mux *Mux) Handler(r *Request) Handler
  • func (mux *Mux) ServeMsg(r *Request) (RequestResponse, error)
• type Request
• type RequestResponse
  • func UnknownMessage(r *Request) (RequestResponse, error)

Types

type Bridge

type Bridge struct {
	// Handler to invoke when messages are received.
	Handler Handler
	// EnableV4 enables the v4+ bridge and the schema v2+ interfaces.
	EnableV4 bool
	// contains filtered or unexported fields
}

Bridge defines the bridge client in the GCS. It acts in many ways analogous to go's `http` package and multiplexer.

It has two fundamentally different dispatch options:

1. Request/Response where using the `Handler` a request of a given type will be dispatched to the apprpriate handler and an appropriate response will respond to exactly that request that caused the dispatch.

2. `PublishNotification` where a notification that was not initiated by a request from any client can be written to the bridge at any time in any order.

func (*Bridge) AssignHandlers

func (b *Bridge) AssignHandlers(mux *Mux, gcs core.Core, host *hcsv2.Host)

AssignHandlers creates and assigns the appropriate bridge events to be listen for and intercepted on `mux` before forwarding to `gcs` for handling.

func (*Bridge) ListenAndServe

func (b *Bridge) ListenAndServe(bridgeIn io.ReadCloser, bridgeOut io.WriteCloser) error

ListenAndServe connects to the bridge transport, listens for messages and dispatches the appropriate handlers to handle each event in an asynchronous manner.

func (*Bridge) PublishNotification

func (b *Bridge) PublishNotification(n *prot.ContainerNotification)

PublishNotification writes a specific notification to the bridge.

type Handler

type Handler interface {
	ServeMsg(*Request) (RequestResponse, error)
}

Handler responds to a bridge request.

func UnknownMessageHandler

func UnknownMessageHandler() Handler

UnknownMessageHandler creates a default HandlerFunc out of the UnknownMessage handler logic.

type HandlerFunc

type HandlerFunc func(*Request) (RequestResponse, error)

HandlerFunc is an adapter to use functions as handlers.

func (HandlerFunc) ServeMsg

func (f HandlerFunc) ServeMsg(r *Request) (RequestResponse, error)

ServeMsg calls f(w, r).

type Mux

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

Mux is a protocol multiplexer for request response pairs following the bridge protocol.

func NewBridgeMux

func NewBridgeMux() *Mux

NewBridgeMux creates a default bridge multiplexer.

func (*Mux) Handle

func (mux *Mux) Handle(id prot.MessageIdentifier, ver prot.ProtocolVersion, handler Handler)

Handle registers the handler for the given message id and protocol version.

func (*Mux) HandleFunc

func (mux *Mux) HandleFunc(id prot.MessageIdentifier, ver prot.ProtocolVersion, handler func(*Request) (RequestResponse, error))

HandleFunc registers the handler function for the given message id and protocol version.

func (*Mux) Handler

func (mux *Mux) Handler(r *Request) Handler

Handler returns the handler to use for the given request type.

func (*Mux) ServeMsg

func (mux *Mux) ServeMsg(r *Request) (RequestResponse, error)

ServeMsg dispatches the request to the handler whose type matches the request type.

type Request

type Request struct {
	// Context is the request context received from the bridge.
	Context context.Context
	// Header is the wire format message header that preceeded the message for
	// this request.
	Header *prot.MessageHeader
	// ContainerID is the id of the container that this message cooresponds to.
	ContainerID string
	// ActivityID is the id of the specific activity for this request.
	ActivityID string
	// Message is the portion of the request that follows the `Header`. This is
	// a json encoded string that MUST contain `prot.MessageBase`.
	Message []byte
	// Version is the version of the protocol that `Header` and `Message` were
	// sent in.
	Version prot.ProtocolVersion
}

Request is the bridge request that has been sent.

type RequestResponse

type RequestResponse interface {
	Base() *prot.MessageResponseBase
}

RequestResponse is the base response for any bridge message request.

func UnknownMessage

func UnknownMessage(r *Request) (RequestResponse, error)

UnknownMessage represents the default handler logic for an unmatched request type sent from the bridge.