[DI] Allow processing env vars

Author: nicolas-grekas

DependencyInjection/FrameworkExtension.php

@@ -36,6 +36,7 @@
 use Symfony\Component\DependencyInjection\ContainerBuilder;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 use Symfony\Component\DependencyInjection\Definition;
+use Symfony\Component\DependencyInjection\EnvVarProcessorInterface;
 use Symfony\Component\DependencyInjection\Exception\LogicException;
 use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;
 use Symfony\Component\DependencyInjection\Reference;
@@ -283,6 +284,8 @@ public function load(array $configs, ContainerBuilder $container)
             ->addTag('console.command');
         $container->registerForAutoconfiguration(ResourceCheckerInterface::class)
             ->addTag('config_cache.resource_checker');
+        $container->registerForAutoconfiguration(EnvVarProcessorInterface::class)
+            ->addTag('container.env_var_processor');
         $container->registerForAutoconfiguration(ServiceSubscriberInterface::class)
             ->addTag('container.service_subscriber');
         $container->registerForAutoconfiguration(ArgumentValueResolverInterface::class)