Doctrine query outside the controller Symfony 2 - symfony

Question

I have some trouble since two days to do a query using a UserRepository outside a controller. I am trying to get a user from the database from a class that I named ApiKeyAuthenticator. I want to execute the query in the function getUsernameForApiKey like in the docs. I think I am suppose to use donctrine as a service but I don't get how to do this.
Thanks for you help in advance!
<?php
// src/AppBundle/Security/ApiKeyUserProvider.php
namespace AppBundle\Security;
use Symfony\Component\Security\Core\User\UserProviderInterface;
use Symfony\Component\Security\Core\User\User;
use Symfony\Component\Security\Core\User\UserInterface;
use Symfony\Component\Security\Core\Exception\UnsupportedUserException;
class ApiKeyUserProvider implements UserProviderInterface
{
public function getUsernameForApiKey($apiKey)
{
// Look up the username based on the token in the database, via
// an API call, or do something entirely different
$username = ...;
return $username;
}
public function loadUserByUsername($username)
{
return new User(
$username,
null,
// the roles for the user - you may choose to determine
// these dynamically somehow based on the user
array('ROLE_API')
);
}
public function refreshUser(UserInterface $user)
{
// this is used for storing authentication in the session
// but in this example, the token is sent in each request,
// so authentication can be stateless. Throwing this exception
// is proper to make things stateless
throw new UnsupportedUserException();
}
public function supportsClass($class)
{
return User::class === $class;
}
}

Answer 1

You have to make your ApiKeyUserProvider a service and inject the UserRepository as a dependency. Not sure if repositories are services in 2.8, so maybe you'll have to inject the EntityManager .
class ApiKeyUserProvider implements UserProviderInterface
{
private $em;
public function __construct(EntityManager $em)
{
$this->em = $em;
}
public function loadUserByUsername($username)
{
$repository = $this->em->getRepository(User::class);
// ...
Now register your class as a service in your services.yml file
services:
app.api_key_user_provider:
class: AppBundle\Security\ApiKeyUserProvider
arguments: ['#doctrine.orm.entity_manager']