services.xml

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <services>

        <service id="acme_oauth_server_bundle.event_listener.update_user_with_ldap_user"
                 class="Acme\OAuthServerBundle\EventListener\UpdateUserWithLdapListener">
            <argument type="service" id="fr3d_ldap.ldap_manager"/>
            <argument type="service" id="fos_user.user_manager" />
            <tag name="kernel.event_listener" event="security.interactive_login" method="onLogin" />
        </service>

    </services>

</container>

UpdateUserWithLdapListener.php

<?php

namespace Acme\OAuthServerBundle\EventListener;

use FOS\UserBundle\Model\UserManagerInterface;
use FR3D\LdapBundle\Ldap\LdapManagerInterface;
use Symfony\Component\Security\Core\User\UserProviderInterface;
use Symfony\Component\Security\Http\Event\InteractiveLoginEvent;

class UpdateUserWithLdapListener
{
    /**
     * @var LdapManagerInterface
     */
    private $ldapManager;

    /**
     * @var UserManagerInterface
     */
    private $userManager;

    public function __construct(LdapManagerInterface $ldapManager, UserManagerInterface $userManager)
    {
        $this->ldapManager = $ldapManager;
        $this->userManager = $userManager;
    }

    public function onLogin(InteractiveLoginEvent $event)
    {
        $username = $event->getAuthenticationToken()->getUser()->getUsername();

        $authUser = $event->getAuthenticationToken()->getUser();
        if (null === $authUser->getId()) {
            return;
        }

        $ldapUser = $this->ldapManager->findUserByUsername($username);

        if (empty($ldapUser)) {
            return;
        }

        $changed = false;

        if (($roles = $ldapUser->getRoles()) != $authUser->getRoles()) {
            $changed = true;
            $authUser->setRoles($roles);
        }

        if (($realName = $ldapUser->getRealName()) != $authUser->getRealName()) {
            $changed = true;
            $authUser->setRealName($realName);
        }

        if ($changed) {
            $this->userManager->updateUser($authUser);
        }
    }
} 

UpdateUserWithLdapListenerTest.php

<?php

namespace Acme\OAuthServerBundle\Tests\EventListener;

use FOS\UserBundle\Model\UserManagerInterface;
use FR3D\LdapBundle\Ldap\LdapManagerInterface;
use Acme\OAuthServerBundle\Entity\User;
use Acme\OAuthServerBundle\EventListener\UpdateUserWithLdapListener;
use Prophecy\PhpUnit\ProphecyTestCase;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
use Symfony\Component\Security\Core\Role\RoleInterface;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Security\Http\Event\InteractiveLoginEvent;

class UpdateUserWithLdapListenerTest extends ProphecyTestCase
{
    private $userManager;

    private $ldapManager;

    public function testNewUser()
    {
        $event = new InteractiveLoginEvent(new Request(), new TestToken());

        $this->ldapManager->findUserByUsername()->shouldNotBeCalled();
        $this->userManager->updateUser()->shouldNotBeCalled();

        $this->onLogin($event);
    }

    public function testNoLdapUser()
    {
        $event = new InteractiveLoginEvent(new Request(), new TestToken(new TestUser(1)));

        $this->ldapManager->findUserByUsername('testuser')->willReturn(null);
        $this->userManager->updateUser()->shouldNotBeCalled();

        $this->onLogin($event);
    }

    public function testNoChanges()
    {
        $event = new InteractiveLoginEvent(new Request(), new TestToken(new TestUser(1)));

        $ldapUser = new TestUser(1);

        $this->ldapManager->findUserByUsername('testuser')->willReturn($ldapUser);
        $this->userManager->updateUser()->shouldNotBeCalled();

        $this->onLogin($event);
    }

    /**
     * @dataProvider getChangedUsers
     */
    public function testChanges($ldapUser)
    {
        $event = new InteractiveLoginEvent(new Request(), new TestToken(new TestUser(1)));

        $this->ldapManager->findUserByUsername('testuser')->willReturn($ldapUser);
        $this->userManager->updateUser($ldapUser)->shouldBeCalled();

        $this->onLogin($event);
    }

    public function getChangedUsers()
    {
        $user1 = new TestUser(1);
        $user1->setRoles(['CHANGED']);

        $user2 = new TestUser(1);
        $user2->setRealName('Changed');

        $user3 = new TestUser(1);
        $user3->setEmail('bla');

        return [
            [$user1],
            [$user2],
        ];
    }

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

        $this->ldapManager = $this->prophesize(LdapManagerInterface::CLASS);
        $this->userManager = $this->prophesize(UserManagerInterface::CLASS);
    }

    /**
     * @param $event
     */
    private function onLogin(InteractiveLoginEvent $event)
    {
        $listener = new UpdateUserWithLdapListener(
            $this->ldapManager->reveal(),
            $this->userManager->reveal()
        );

        $listener->onLogin($event);
    }
}

class TestUser extends User
{
    public function __construct($id)
    {
        $this->id = $id;
        $this->username = 'testuser';
    }
}

class TestToken implements TokenInterface
{
    public function __construct(UserInterface $user = null)
    {
        $this->user = (null === $user) ? new TestUser(null) : $user;
    }

    public function serialize()
    {
    }

    public function unserialize($serialized)
    {
    }

    public function __toString()
    {
    }

    public function getRoles()
    {
    }

    public function getCredentials()
    {
    }

    public function getUser()
    {
        return $this->user;
    }

    public function setUser($user)
    {
    }

    public function getUsername()
    {
    }

    public function isAuthenticated()
    {
    }

    public function setAuthenticated($isAuthenticated)
    {
    }

    public function eraseCredentials()
    {
    }

    public function getAttributes()
    {
    }

    public function setAttributes(array $attributes)
    {
    }

    public function hasAttribute($name)
    {
    }

    public function getAttribute($name)
    {
    }

    public function setAttribute($name, $value)
    {
    }
}