My requirements:

  • Moving application specific configurations into separate application bundles (not separate app/ folders)
  • Retaining common configurations in the app/config/config_*.yml files
  • Retaining common practices such as calling app/console just adding a parameter to specify the application


  1. Change your apache2 vhost to add a (conditional?) environment variable
    # ...
    # The RegEx below matches subdomains
    SetEnvIf Host nth\..+? SYMFONY_APP=nth
    # ...
  2. Create app/NthKernel.php which extends AppKernel
  3. Overwrite NthKernel::$name = 'nth'
  4. Overwrite NthKernel::serialize, NthKernel::unserialize to ensure the correct name is kept after serialization/deserialization
  5. Overwrite NthKernel::getCacheDir to ensure the cache dirs are split based on the application name:

    public function getCacheDir()
       return $this->rootDir.'/cache/'.$this->name.'/'.$this->environment;

  6. Overwrite the NthKernel::registerContainerConfiguration to load configurations based on the application name and environment. In my case I loaded all config.yml files from any installed bundle:
    public function registerContainerConfiguration(LoaderInterface $loader)
        $env = $this->getEnvironment();
        foreach ($this->bundles as $bundle) {
            $dir = $bundle->getPath() . '/Resources/config/';
            if (file_exists($path = $dir . 'config_'.$env.'.yml')) {
            } elseif (file_exists($path = $dir . 'config.yml')) {
        $dir = __DIR__.'/config/';
        if (file_exists($path = $dir . 'config_'.$env.'.yml')) {
        } elseif (file_exists($path = $dir . 'config.yml')) {
  7. Change web/app.php/web/app_dev.php to ensure they instantiate NthKernel and NthCache based on the environment variable apache is providing (SYMFONY_APP):
    $app = ucfirst(getenv('SYMFONY_APP'));
    require_once __DIR__.'/../app/AppKernel.php';
    require_once __DIR__.'/../app/'.$app.'Kernel.php';
    //require_once __DIR__.'/../app/AppCache.php';
    //require_once __DIR__.'/../app/'.$app.'Cache.php';
    $kernel = $app.'Kernel';
    $kernel = new $kernel('dev', true);
    //$cache = $app.'Cache';
    //$kernel = new $cache($kernel);
  8. Change app/console to allow you to specify which application you need to use
    $app = ucfirst($input->getParameterOption(array('--app', '-a'), getenv('SYMFONY_APP')));
    $env = $input->getParameterOption(array('--env', '-e'), getenv('SYMFONY_ENV') ?: 'dev');
    // ...
    /* Move require_once after you initialized the `$app` variable */
    require_once __DIR__.'/AppKernel.php';
    require_once __DIR__.'/'.$app.'Kernel.php';
    $kernel = $app.'Kernel';
    $kernel = new $kernel($env, $debug);
    $application = new Application($kernel);
           new InputOption(
               'The Application name.',
  9. Use app/console by specifying the application you need to use
    app/console --app=nth --env=dev debug:router
    app/console --app=nth --env=dev debug:container

Other resources:

JoliCode wrote this article on the topic.

Their approach on the problem seems more idiomatic — creating a structure application specific subfolders (apps/nth) each with its own AppKernel, apps/nth/cache and apps/nth/config etc..