http-jsonrpc-server

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- http-jsonrpc-server
- Install
- Usage
- Specifying a Path
- Optional Callbacks
- Adding/Updating Methods
- Closing the Server
- Basic Authentication
- Native HTTP Server
- Exposed Constants
- API Documentation
- RpcServer
- new RpcServer(options)
- rpcServer.setMethod(name, method)
- rpcServer.listen(port, host) ⇒ Promise.<number>
- rpcServer.close() ⇒ Promise.<void>
- Sample Requests
- Sum
- Sum (Batched)
- Wait

A simple and lightweight library for creating a JSON-RPC 2.0 compliant HTTP server.

This package complies with the JSON-RPC 2.0 and JSON-RPC 2.0 Transport: HTTP specifications.

Install

To install http-jsonrpc-server in the current directory, run:

``bash
npm install http-jsonrpc-server --save
`

Usage

Below is code to create a server with two exposed methods and begin listening on a given port.

`javascript
const RpcServer = require('http-jsonrpc-server');

function sum(arr) {
let total = 0;
for (let n = 0; n < arr.length; n += 1) {
total += arr[n];
}
return total;
}

async function wait(params) {
return new Promise((resolve) => {
setTimeout(() => {
resolve(true);
}, params.ms);
});
}

const rpcServer = new RpcServer({
methods: {
sum,
wait,
}
});
rpcServer.setMethod('sum', sum);
rpcServer.setMethod('wait', wait);
rpcServer.listen(9090, '127.0.0.1').then(() => {
console.log('server is listening at http://127.0.0.1:9090/');
}
`

$3

`javascript
const rpcServer = new RpcServer({
path: '/api'
});
rpcServer.listen(9090, '127.0.0.1').then(() => {
console.log('server is listening at http://127.0.0.1:9090/api');
}
`

$3

onServerError will be called if the server emits an error. onRequest, and onRequestError, and onResult will be called each time a method is called, throws an error, or returns a result respectively.

`javascript
const rpcServer = new RpcServer({
onRequest: (request) => {
console.log(JSON.stringify(request));
// sample output: {"jsonrpc":"2.0","id":1,"method":"sum","params":[1,2,3]}
},
onRequestError: (err, id) => {
console.error('request ' + id + ' threw an error: ' + err);
},
onResult: (result, id) => {
console.log(result); // sample output: 6
},
onServerError: (err) => {
console.error('the server threw an error: ' + err)
},
});
`

$3

You can register new methods or update existing ones after the server has been created.

`javascript
rpcServer.setMethod('sum', sum);
`

$3

`javascript
rpcServer.close().then(() => {
console.log('server stopped listening');
}
`

$3

You can optionally enable Basic Authentication by specifying credentials when creating the server. Any requests will then require an Authorization header with [username]:[password] encoded in Base64. Note that TLS is not currently supported, therefore all traffic is unencrypted and these credentials can be stolen by anyone relaying or listening to requests. This authentication alone should not be considered secure over public networks.

`javascript
const rpcServer = new RpcServer({
username: 'johndoe',
password: 'wasspord', // ignored unless username is specified
realm: 'rpc' // realm defaults to "Restricted" if not specified
});
`

$3

You can access the underlying http.Server object with rpcServer.server.

`javascript
if (rpcServer.server.listening) {
console.log('server is listening');
}
`

$3

`javascript
console.log(rpcServer.PARSE_ERROR); // -32700
console.log(rpcServer.INVALID_REQUEST); // -32600
console.log(rpcServer.METHOD_NOT_FOUND); // -32601
console.log(rpcServer.INVALID_PARAMS); // -32602
console.log(rpcServer.SERVER_ERROR); // -32000
console.log(rpcServer.SERVER_ERROR_MAX); // -32099
`

API Documentation

RpcServer

| Param | Type | Description |
| --- | --- | --- |
| options | Object | Optional parameters for the server |
| options.methods | Object | A map of method names to functions. Method functions are passed one parameter which will either be an Object or a string array |
| options.context | | Context to be used as this for method functions. |
| options.path | string | The path for the server |
| options.onRequest | function | Callback for when requests are received, it is passed an Object representing the request |
| options.onRequestError | function | Callback for when requested methods throw errors, it is passed an error and request id |
| options.onResult | function | Callback for when requests are successfully returned a result. It is passed the response object and request id |
| options.onServerError | function | Callback for server errors, it is passed an Error |
| options.username | string | Username for authentication. If provided, Basic Authentication will be enabled and required for all requests. |
| options.password | string | Password for authentication, ignored unless a username is also specified. |
| options.realm | string | Realm for authentication, ignored unless a username is also specified, defaults to Restricted if not specified. |

$3

| Param | Type | Description |
| --- | --- | --- |
| port | number | The port number to listen on - an arbitrary available port is used if no port is specified |
| host | string | The host name or ip address to listen on - the unspecified IP address (0.0.0.0 or (::)) is used if no host is specified |

$3

`http
POST / HTTP/1.1
Host: 127.0.0.1:9090
Content-Type: application/json
Accept: application/json
Content-Length: 56

{"jsonrpc":"2.0","id":1,"method":"sum","params":[1,2,3]}
`

`http
connection: close
content-type: application/json
content-length: 35

{"jsonrpc":"2.0","id":1,"result":6}
`

$3

`http
POST / HTTP/1.1
Host: 127.0.0.1:9090
Content-Type: application/json
Accept: application/json
Content-Length: 115

[{"jsonrpc":"2.0","id":1,"method":"sum","params":[1,2,3]},{"jsonrpc":"2.0","id":2,"method":"sum","params":[4,5,6]}]
`

`http
connection: close
content-type: application/json
content-length: 74

[{"jsonrpc":"2.0","id":1,"result":6},{"jsonrpc":"2.0","id":2,"result":15}]
`

$3

`http
POST / HTTP/1.1
Host: 127.0.0.1:9090
Content-Type: application/json
Accept: application/json
Content-Length: 59

{"jsonrpc":"2.0","id":1,"method":"wait","params":{"ms":50}}
`

`http
connection: close
content-type: application/json
content-length: 38

{"jsonrpc":"2.0","id":1,"result":true}
``