gistfile1.php

<?php

namespace ...EventListener;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\HttpKernelInterface;
use Symfony\Component\Security\Http\Event\InteractiveLoginEvent;
use Symfony\Component\Security\Http\SecurityEvents;


class SessionSubscriber implements EventSubscriberInterface
{


    /**
     * @param InteractiveLoginEvent $event
     */
    public function onInteractiveLogin(InteractiveLoginEvent $event)
    {
        $session = $event->getRequest()->getSession();
        $id = $event->getAuthenticationToken()->getUser()->getId();

        $session->set('user_id', $id);
    }

    /**
     * {@inheritdoc}
     */
    public static function getSubscribedEvents()
    {
        return [
            SecurityEvents::INTERACTIVE_LOGIN => array('onInteractiveLogin'),
        ];
    }
}