Socket.io: Connect from one server to another

Question

I'm trying to make a nodejs(socket.io) server to communicate with another one. So the client emits an event to the 'hub' server and this server emits an event to some second server for processing the action.

I tried to do:

var io_client = require( 'socket.io-client' );

and then,

io_client.connect( "second_server_host" ); 

it seems to work for connection but you can't do anything with this:

debug - set close timeout for client 15988842591410188424
info  - socket error Error: write ECONNABORTED
 at errnoException (net.js:642:11)
 at Socket._write (net.js:459:18)
 at Socket.write (net.js:446:15)

I guess I'm doing it wrong and missing something obvious.

Any suggestions?

Answer 1

Just came across this question, and another just like it with a much better answer.

https://stackoverflow.com/a/14118102/1068746

You can do server to server. The "client" code remains the same as if it was on the browser. Amazing isn't it?

I just tried it myself, and it works fine..

I ran 2 servers - using the same exact code - once on port 3000 as server, and another on port 3001 as client. The code looks like this:

  , io = require('socket.io')
  , ioClient = require('socket.io-client')

   .... 

   if ( app.get('port') == 3000 ){

    io.listen(server).sockets.on('connection', function (socket) {
      socket.on('my other event', function (data) {
        console.log(data);
      });
    });
}else{
    function emitMessage( socket ){
        socket.emit('my other event', { my: 'data' });
        setTimeout(function(){emitMessage(socket)}, 1000);
    }
    var socket = ioClient.connect("http://localhost:3000");
    emitMessage(socket);
}

And if you see on the server side a "{my:data}" print every second, everything works great. Just make sure to run the client (port 3001) after the server (port 3000).

Answer 2

For anyone searching for a short working example, see below. This example works with [email protected] and [email protected].

var port = 3011;

var server = require( 'http' ).createServer( ).listen( port, function () {
    console.log( "Express server listening on port " + port );
} );

var io = require( 'socket.io' ).listen( server ).set( "log level", 0 );

io.sockets.on( "connection", function ( socket ) {
    console.log( 'Server: Incoming connection.' );
    socket.on( "echo", function ( msg, callback ) {
        callback( msg );
    } );
} );


var ioc = require( 'socket.io-client' );
var client = ioc.connect( "http://localhost:" + port );

client.once( "connect", function () {
    console.log( 'Client: Connected to port ' + port );

    client.emit( "echo", "Hello World", function ( message ) {
        console.log( 'Echo received: ', message );
        client.disconnect();
        server.close();
    } );
} );