Working with WebSockets and Larvel is extremely easy! If you are new to Laravel it has an event system that you can use to dispatch events for other parts of your PHP code to use. As well as Laravel supports Redis and Pusher for dispatching events via WebSockets. Pusher is a fully hosted service that will handle the Node.js side of things for you. I hover will cover using Laravel events with Redis to broadcast events to Socket.io and using Supervisor to keep all the processes needed running by default. The current version of Laravel as of this writing is 5.2 which you should already have installed and I will be assuming you are using Laravel Homstead.

Dependencies and Configuration

So lets get started with installing the required dependencies.

$ composer require predis/predis
$ npm install express ioredis socket.io --save

We will then need to update our .env with BROADCAST_DRIVER=redis.

Event Class

Now we will need to create a new event.

$ php artisan make:event EventName

Go ahead open the new event app/Events/EventName.php.

You need to make sure that your event implements ShouldBroadcast by default it does not.

<?php
// ...
class EventName extends Event implements ShouldBroadcast
// ...

For this example we will use a $data property to pass information to socket.io however by default you will have access to any public property.

<?php
// ...
public $data;
// ...
public function __construct($some_data)
{
    $this->data = compact('some_data');
}
// ...

Then you will need to set the channel you are going to broadcast the events on. We will use this later with Socket.io to listen for the events.

<?php
// ...
public function broadcastOn()
{
    return ['event-example'];
}
// ...

Our whole event class should now look like this.

<?php

namespace App\Events;

use App\Events\Event;
use Illuminate\Queue\SerializesModels;
use Illuminate\Contracts\Broadcasting\ShouldBroadcast;

class EventName extends Event implements ShouldBroadcast
{
    use SerializesModels;

    public $data;

    /**
     * Create a new event instance.
     *
     * @return void
     */
    public function __construct($some_data)
    {
        $this->data = compact('some_data');
    }

    /**
     * Get the channels the event should be broadcast on.
     *
     * @return array
     */
    public function broadcastOn()
    {
        return ['event-example'];
    }
}

Socket.io

Now we will need to make a socket.js file in the root of our Laravel installation and place the following into it.

var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var Redis = require('ioredis');
var redis = new Redis();
redis.subscribe('event-example', function(err, count) {
});
redis.on('message', function(channel, message) {
    console.log('Message Recieved: ' + message);
    message = JSON.parse(message);
    io.emit(channel + ':' + message.event, message.data);
});
http.listen(3000, function(){
    console.log('Listening on Port 3000');
});

If you want to update the channel you will need to change event-example in redis.subscribe('event-example', function(err, count) { });.

Now we are ready to run the socket.js file and Redis in separate tabs on your server run the following.

$ node socket.js
# You should see Listening on Port 3000
$ redis-server --port 3001
# You should see a whole bunch of output

Event listener

Now for simplicity you can add the following to your main view template. This basically listens for an event on the event-example we have setup that as fired by the EventName class. You will want to move this into is own separate JS file.

<script src="https://cdn.socket.io/socket.io-1.4.5.js"></script>
<script>
var socketURL = 'http://192.168.10.10:3000'; // 192.168.10.10 can be replaced with the IP address of your server.

// If you are using Elixir/Browserify use commented out socket instead.
var socket = io(socketURL);
// var socket = require('socket.io-client')(socketURL);

// The event name is created by the event channel (example-event) we set earlier
// and the class name with the full namespace (App\Events\EventName).
socket.on('event-example:App\\Events\\EventName', function (event) {
    alert(event.data.some_data);
});
</script>

Event testing

For simplicity sake when testing we can just add a route to fire the event. In reality this will happen elsewhere possibly in a controller. The main thing to take away is Event::fire(new EventName('Some data about the event.')); will be how you can fire the event.

Route::group(['middleware' => 'web'], function () {
    Route::get('/fire', function () {
        Event::fire(new EventName('Event data'));

        return 'Event Fired';
    });
});

Now if you open your site in one tab and go to /fire in the other. Then in the first tab you should see an alert with the text Event data. Now you have a fully functional setup with Laravel and WebSockets!

Supervisor

So obviously we do not want to manually run node socket.js and redis-server --port 3001 when we start our server. As well as make sure both commands are never closed out. So this is where Supervisor comes into play. It will handle starting both services and making sure they stay up continuously.

The following instructions will happen on your server.

If you do not already have Supervisor installed you can install it via sudo apt-get install supervisor. Then you will need to restart Supervisor via sudo service supervisor restart

Now we need to set the configuration file for socket.js via sudo nano /etc/supervisor/conf.d/socket.conf.

# socket.conf content
[program:socket]
command=node /path/to/install/socket.js # IMPOTANT: Update /path/to/install
autostart=true
autorestart=true
stderr_logfile=/var/log/socket.err.log
stdout_logfile=/var/log/socket.out.log

Then we will need to setup the configuration for Redis sudo nano /etc/supervisor/conf.d/redis.conf

# redis.conf content
[program:redis]
command=redis-server --port 3001
autostart=true
autorestart=true
stderr_logfile=/var/log/redis.err.log
stdout_logfile=/var/log/redis.out.log

Now we need to tell Supervisor about our new configuration.

$ sudo supervisorctl reread
$ sudo supervisorctl update

You can verify everything went ok by the following

$ tail /var/log/socket.out.log
# You should see Listening on Port 3000
$ tail /var/log/redis.out.log
# You should see a whole bunch of output

If something does not seem to work correctly you can check the error logs via the following.

$ tail /var/log/socket.err.log
$ tail /var/log/redis.err.log

So thats all there basically is now go out and build something awesome!