[symfony] Accessing the logged-in user in a template

I'm using FOSuserbundle to get started with User registration https://github.com/FriendsOfSymfony/FOSUserBundle

I've got it registering / logging in and out. What I want to do now is grab the logged in users data and present it on every page of my site. Like "Hi username" in the header type of thing.

It seems like embedding a controller in my app/Resources/views/base.html.twig is the best way to do this http://symfony.com/doc/current/book/templating.html#embedding-controllers

So I wrote my controller to access the user profile data. What I can't figure out is how to access FOS methods in my embedded controller. So from my Acme/UserBundle/Controller/UserController.php I want to do this:

public function showAction()
{
    $user = $this->container->get('security.context')->getToken()->getUser();
    if (!is_object($user) || !$user instanceof UserInterface) {
        throw new AccessDeniedException(
               'This user does not have access to this section.');
    }

    return $this->container->get('templating')
      ->renderResponse('FOSUserBundle:Profile:show.html.'.$this->container
      ->getParameter('fos_user.template.engine'), array('user' => $user));
}

which I grabbed from: vendor/bundles/FOS/UserBundle/Controller/ProfileController.php

{{ app.user.username|default('') }}

Just present login username for example, filter function default('') should be nice when user is NOT login by just avoid annoying error message.

For symfony 2.6 and above we can use

{{ app.user.getFirstname() }}

as app.security global variable for Twig template has been deprecated and will be removed from 3.0

more info:

http://symfony.com/blog/new-in-symfony-2-6-security-component-improvements

and see the global variables in

http://symfony.com/doc/current/reference/twig_reference.html