node.js listen for UDP and forward to connected http web clients

Question

I\'m new to node.js, so forgive the ignorance if this is simple.

What I want to do is setup a simple node.js http server to which a web-client connects. I also want

Answer 1

I made a running example for you to get going with: http://runnable.com/UXsar5hEezgaAACJ

For now it's just a loopback client -> socket.io -> udp client -> udp server -> socket.io - > client.

here's the core of it:

var http = require('http');
var fs = require('fs');
var html = fs.readFileSync(__dirname + '/index.html');

//Initialize the HTTP server on port 8080, serve the index.html page
var server = http.createServer(function(req, res) {
  res.writeHead(200, { 
    'Content-type': 'text/html'
  });
  res.end(html);
}).listen( process.env.OPENSHIFT_NODEJS_PORT, process.env.OPENSHIFT_NODEJS_IP, function() {
  console.log('Listening');
});

var io = require('socket.io').listen(server);

io.set('log level', 0);

io.sockets.on('connection', function (socket) {
  socket.emit('message', 'connected');
  socket.on('message', function (data) {
    console.log(data);
    var address = srv.address();
    var client = dgram.createSocket("udp4");
    var message = new Buffer(data);
    client.send(message, 0, message.length, address.port, address.address, function(err, bytes) {
      client.close();
    });
  });
});

var dgram = require('dgram');

//Initialize a UDP server to listen for json payloads on port 3333
var srv = dgram.createSocket("udp4");
srv.on("message", function (msg, rinfo) {
  console.log("server got: " + msg + " from " + rinfo.address + ":" + rinfo.port);
  io.sockets.emit('message', 'udp');
});

srv.on("listening", function () {
  var address = srv.address();
  console.log("server listening " + address.address + ":" + address.port);
});

srv.on('error', function (err) {
  console.error(err);
  process.exit(0);
});

srv.bind();