koa-wss

💙 Support wss:// in your Koa app 💙

This is a fork/copy of the excellent package koa-websocket by Jonathan Cremin, with secure Web Socket functionality added.

Koa's listen method just calls http.createServer(options).listen(...), so this calls https.createServer(options).listen(...) instead and provides a parameter to pass in the HTTPS options (like the certificate and stuff).

If you don't supply an httpsOptions argument, koa-wss will do what koa-websocket does and just use Koa's built-in listen method.

See Koa's docs about this here.

Installation

npm install koa-wss --save

Usage

Example with Let's Encrypt (the Greenlock package):

const Koa = require('koa');
const greenlock = require('greenlock-express');
const websockify = require('koa-wss');
 
const le = greenlock.create({
  // all your sweet Let's Encrypt options here
});
 
// the magic happens right here
const app = websockify(new Koa(), wsOptions, le.httpsOptions);
 
// async/await is of course supported
app.ws.use(async (ctx, next) => {
   // the websocket is added to the context as `ctx.websocket`.
  await bananas();
  ctx.websocket.on('message', function(message) {
    // do something
  });
});
 
app.listen(3000);

Another example:

const fs = require('fs');
const path = require('path');
const Koa = require('koa');
const route = require('koa-route');
const websockify = require('koa-wss');
 
// using a local certificate, but whatever you normally put in HTTPS options works here
const httpsOptions = {
  key: fs.readFileSync(path.resolve(__dirname, './test/certs/server.key')),
  cert: fs.readFileSync(path.resolve(__dirname, './test/certs/server.crt'))
};
 
// the main event
const app = websockify(new Koa(), {}, httpsOptions);
 
// Note it's app.ws.use and not app.use
// This example uses koa-route
app.ws.use(route.all('/test', (ctx, next) => {
  ctx.websocket.send('Hello World');
  ctx.websocket.on('message', (message) => {
    // do something with the message from client
    console.log(message);
  });
  return next()
}));
 
app.listen(3000);
 

API

websockify(KoaApp, WebSocketOptions, httpsOptions)

The WebSocket options object just get passed right through to the new WebSocketServer call. koa-wss passes in { server: httpsServer } automatically because that's the whole point.

The HTTPS options object gets passed right into https.createServer(options). If you don't specify these options with your certificate info, it will just set up an HTTP Koa server (the default).

License

MIT