rpc

Documentation

Overview

HTTP RPC server supporting calls via uri params, jsonrpc, and jsonrpc over websockets

Client Requests

Suppose we want to expose the rpc function `HelloWorld(name string, num int)`.

## GET (URI)

As a GET request, it would have URI encoded parameters, and look like:

``` curl 'http://localhost:8008/hello_world?name="my_world"&num=5' ```

Note the `'` around the url, which is just so bash doesn't ignore the quotes in `"my_world"`. This should also work:

``` curl http://localhost:8008/hello_world?name=\"my_world\"&num=5 ```

A GET request to `/` returns a list of available endpoints. For those which take arguments, the arguments will be listed in order, with `_` where the actual value should be.

## POST (JSONRPC)

As a POST request, we use JSONRPC. For instance, the same request would have this as the body:

```

{
  "jsonrpc": "2.0",
  "id": "anything",
  "method": "hello_world",
  "params": {
    "name": "my_world",
    "num": 5
  }
}

```

With the above saved in file `data.json`, we can make the request with

``` curl --data @data.json http://localhost:8008 ```

## WebSocket (JSONRPC)

All requests are exposed over websocket in the same form as the POST JSONRPC. Websocket connections are available at their own endpoint, typically `/websocket`, though this is configurable when starting the server.

Server Definition

Define some types and routes:

```

type ResultStatus struct {
	Value string
}

// Define some routes

var Routes = map[string]*rpcserver.RPCFunc{
	"status": rpcserver.NewRPCFunc(Status, "arg"),
}

// an rpc function

func Status(v string) (*ResultStatus, error) {
	return &ResultStatus{v}, nil
}

```

Now start the server:

``` mux := http.NewServeMux() rpcserver.RegisterRPCFuncs(mux, Routes) wm := rpcserver.NewWebsocketManager(Routes) mux.HandleFunc("/websocket", wm.WebsocketHandler) logger := log.NewTMLogger(log.NewSyncWriter(os.Stdout))

go func() {
	_, err := rpcserver.StartHTTPServer("0.0.0.0:8008", mux, logger)
	if err != nil {
		panic(err)
	}
}()

```

Note that unix sockets are supported as well (eg. `/path/to/socket` instead of `0.0.0.0:8008`)

Now see all available endpoints by sending a GET request to `0.0.0.0:8008`. Each route is available as a GET request, as a JSONRPCv2 POST request, and via JSONRPCv2 over websockets.

Examples

* [Tendermint](https://github.com/tendermint/tendermint/blob/master/rpc/core/routes.go) * [tm-monitor](https://github.com/tendermint/tools/blob/master/tm-monitor/rpc.go)

Index

• Constants

Constants

const Fix = "0"

const Maj = "0"

const Min = "7"

const Version = Maj + "." + Min + "." + Fix