Symfony3 project deployment to prod server using Deployer.org - deployment

Question

I'm trying to deploy my symfony3 project to production server Using deployer.ord. I've been through all around deployer.org and not sure what is going wrong. Below is my deploy.php file
<?php
/*
* This file has been generated automatically.
* Please change the configuration for correct use deploy.
*/
require 'recipe/symfony.php';
// Set configurations
set('repository', 'git#github.com:XXXXXX/YYYYYY');
set('shared_files', ['app/config/parameters.yml']);
set('shared_dirs', ['app/logs']);
set('writable_dirs', ['app/cache', 'app/logs']);
// Configure servers
server('production', 'dummysite.com', '21')
->user('2136439')
->password('123456')
->env('deploy_path', '/home/www/dummysite.com/web')
->stage('production');
/**
* Restart php-fpm on success deploy.
*/
task('php-fpm:restart', function () {
// Attention: The user must have rights for restart service
// Attention: the command "sudo /bin/systemctl restart php-fpm.service" used only on CentOS system
// /etc/sudoers: username ALL=NOPASSWD:/bin/systemctl restart php-fpm.service
run('sudo /bin/systemctl restart php-fpm.service');
})->desc('Restart PHP-FPM service');
after('success', 'php-fpm:restart');
/**
* Attention: This command is only for for example. Please follow your own migrate strategy.
* Attention: Commented by default.
* Migrate database before symlink new release.
*/
// before('deploy:symlink', 'database:migrate');
The error that i am getting is : PHP Notice: Connection terminated by the server
I have already tried this resource but still no luck
http://www.issart.com/blog/deployment-of-symfony2-application-using-deployer/
I wonder if i am using the right credentials (i am using ftp ones) for deployment.
I was also not able to find much of info online on deployer.org and a step-by-step on how to deploy and debug so any help would be highly appreciated.

Answer 1

a bit later :)
<?php
namespace Deployer;
require 'recipe/symfony3.php';
detail here : https://github.com/deployphp/deployer/blob/master/recipe/symfony3.php