Сервис Configurator в Symfony

config/services.yaml — autowire загрузит конфигуратор

    App\Services\ServiceManager:
        configurator: 'App\Services\ServiceManagerConfigurator:configure'

src/Services/ServiceManagerConfigurator.php

<?php
namespace App\Services;
use Doctrine\ORM\EntityManagerInterface;
class ServiceManagerConfigurator {
  private $em;
  public function __construct(EntityManagerInterface $entityManager) {
    $this->em = $entityManager;
  }
  public function configure( ServiceManager $serviceManager ){
    $serviceManager->setEntityManager($this->em);
  }
}

src/Services/ServiceManager.php

<?php
namespace App\Services;
use Doctrine\ORM\EntityManagerInterface;
class ServiceManager {
  private $em;
  public function exec(){
    ///
    //var_dump($this->em);
  }
  public function setEntityManager( EntityManagerInterface $entityManager){
    $this->em = $entityManager;
  }
}