Can I set up socket.io chat on heroku?

Question

I have a simple socket.io chat application which I've uploaded to one of the new Heroku 'cedar' stacks.

Now I almost have everything working but I've hit one stumbling block. On my localhost, I open a connection to the socket server from the client with:

// lots of HTML omitted
socket = new io.Socket('localhost', {port: 8888});

But on Heroku, I obviously must substitute something else in for these values.

I can get the port from the process object on the server like so:

port = process.env.PORT || 8888

and pass that to the view.

But what do I substitute for 'localhost'?

Solution 1

This has now changed as of Oct 2013, heroku have added websocket support:

https://devcenter.heroku.com/articles/node-websockets

Use:

heroku labs:enable websockets

To enable websockets and dont forget to remove:

io.configure(function () { 
  io.set("transports", ["xhr-polling"]); 
  io.set("polling duration", 10); 
}); 

Solution 2

The correct way according the article on heroku is:

io.configure(function () { 
  io.set("transports", ["xhr-polling"]); 
  io.set("polling duration", 10); 
});
socket = new io.Socket();

This ensures that io.Socket won't try to use WebSockets.

Solution 3

I was able to get Socket.IO v0.8 to work on Heroku Cedar by doing the following:

Within the Express app (in CoffeeScript in my case):

app = express.createServer();
socket = require("socket.io")

...

io = socket.listen(app);
io.configure () ->
  io.set("transports", ["xhr-polling"])
  io.set("polling duration", 10)

io.sockets.on('connection', (socket) ->
  socket.on('myaction', (data) ->
    ...
    socket.emit('result', {myData: data})

### The port setting is needed by Heroku or your app won't start
port = process.env.PORT || 3000;
app.listen(port);

And within the front-facing Javascript of your application:

var socket = io.connect(window.location.hostname);
function sendSocketRequest() {
  socket.emit('myaction', $("#some_field").val());
}

socket.on('result', function(data) {
  console.log(data);
}

---

Helpful links:

• Heroku Node help
• Heroku Socket.IO help

Solution 4

After trying every combination under the sun I finally just left it blank. Lo and behold that works perfectly. You don't even need the port.

socket = new io.Socket();

Solution 5

I was also having this problem on heroku. I was able to make it work using the hostname "myapp.herokuapp.com" (or simply window.location.hostname, to work both local and in production) and setting the port to 80. I'm using SocketIO 0.6.0.

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