jhttp

Documentation

Overview

Package jhttp implements a bridge from HTTP to JSON-RPC. This permits requests to be submitted to a JSON-RPC server using HTTP as a transport.

Example

package main

import (
	"context"
	"fmt"
	"io/ioutil"
	"log"
	"net/http"
	"net/http/httptest"
	"strings"

	"github.com/creachadair/jrpc2/handler"
	"github.com/creachadair/jrpc2/jhttp"
	"github.com/creachadair/jrpc2/server"
)

func main() {
	// Set up a local server to demonstrate the API.
	loc := server.NewLocal(handler.Map{
		"Test": handler.New(func(ctx context.Context, ss ...string) (string, error) {
			return strings.Join(ss, " "), nil
		}),
	}, nil)
	defer loc.Close()

	b := jhttp.NewBridge(loc.Client)
	defer b.Close()

	hsrv := httptest.NewServer(b)
	defer hsrv.Close()

	rsp, err := http.Post(hsrv.URL, "application/json", strings.NewReader(`{
  "jsonrpc": "2.0",
  "id": 10235,
  "method": "Test",
  "params": ["full", "plate", "and", "packing", "steel"]
}`))
	if err != nil {
		log.Fatalf("POST request failed: %v", err)
	}
	body, err := ioutil.ReadAll(rsp.Body)
	rsp.Body.Close()
	if err != nil {
		log.Fatalf("Reading response body: %v", err)
	}

	fmt.Println(string(body))
}

Output:

{"jsonrpc":"2.0","id":10235,"result":"full plate and packing steel"}

Index

• func HTTPRequest(ctx context.Context) *http.Request
• type Bridge
  • func NewBridge(c *jrpc2.Client) *Bridge
  • func (b *Bridge) Close() error
  • func (b *Bridge) ServeHTTP(w http.ResponseWriter, req *http.Request)
• type Channel
  • func NewChannel(url string, opts *ChannelOptions) *Channel
  • func (c *Channel) Close() error
  • func (c *Channel) Recv() ([]byte, error)
  • func (c *Channel) Send(msg []byte) error
• type ChannelOptions
• type HTTPClient

Examples

• Package

Functions

func HTTPRequest

func HTTPRequest(ctx context.Context) *http.Request

HTTPRequest returns the HTTP request associated with ctx, or nil. The context passed to the JSON-RPC client by the Bridge will contain this value.

Types

type Bridge

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

A Bridge is a http.Handler that bridges requests to a JSON-RPC client.

The body of the HTTP POST request must contain the complete JSON-RPC request message, encoded with Content-Type: application/json. Either a single request object or a list of request objects is supported.

If the request completes, whether or not there is an error, the HTTP response is 200 (OK) for ordinary requests or 204 (No Response) for notifications, and the response body contains the JSON-RPC response.

If the HTTP request method is not "POST", the bridge reports 405 (Method Not Allowed). If the Content-Type is not application/json, the bridge reports 415 (Unsupported Media Type).

The bridge attaches the inbound HTTP request to the context passed to the client, allowing an EncodeContext callback to retrieve state from the HTTP headers. Use jhttp.HTTPRequest to retrieve the request from the context.

func NewBridge

func NewBridge(c *jrpc2.Client) *Bridge

NewBridge constructs a new Bridge that dispatches requests through c. It is safe for the caller to continue to use c concurrently with the bridge, as long as it does not close the client.

func (*Bridge) Close

func (b *Bridge) Close() error

Close shuts down the client associated with b and reports the result from its Close method.

func (*Bridge) ServeHTTP

func (b *Bridge) ServeHTTP(w http.ResponseWriter, req *http.Request)

ServeHTTP implements the required method of http.Handler.

type Channel

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

A Channel implements an channel.Channel that dispatches requests via HTTP to a user-provided URL. Each message sent to the channel is an HTTP POST request with the message as its body.

func NewChannel

func NewChannel(url string, opts *ChannelOptions) *Channel

NewChannel constructs a new channel that posts to the specified URL.

func (*Channel) Close

func (c *Channel) Close() error

Close shuts down the channel, discarding any pending responses.

func (*Channel) Recv

func (c *Channel) Recv() ([]byte, error)

Recv receives the next available response and reports its body.

func (*Channel) Send

func (c *Channel) Send(msg []byte) error

Send forwards msg to the server as the body of an HTTP POST request.

type ChannelOptions

type ChannelOptions struct {
	// The HTTP client to use to send requests. If nil, uses http.DefaultClient.
	Client HTTPClient
}

ChannelOptions gives optional parameters for constructing an HTTP channel. A nil *ChannelOptions is ready for use, and provides default options as described.

type HTTPClient

type HTTPClient interface {
	Do(*http.Request) (*http.Response, error)
}

HTTPClient is the interface to an HTTP client used by a Channel. It is compatible with the standard library http.Client type.