Use sessions across client requests

gistfile1.php

<?php

class YourTestKernel extends \yourKernel
{
    protected $session;

    protected function initializeContainer()
    {
        parent::initializeContainer();

        // first use
        if ($this->session === null) {
            $this->session = $this->container->get('session');
        } else {
            $this->container->set('session', $this->session);
        }
    }
}