In Symfony sub-request, $this->container is null

Question

I want to implement a batch request api using symfony.
So, I using the sub-request in symfony. But in each controller, the $this->container is null. Because I am using service container in my project.

So, the batch request parameter like below:

{request: [{"url":"/api/user?username=test"},  {"url":"/api/thread?id=123"}]}

And the source code like below:
I want to generate some sub-request to reduce outside HTTP request.

foreach($request_list as $k => $v) {
    parse_str(parse_url($v['url'], PHP_URL_QUERY), $params);
    $req = Request::create(
        parse_url($v['url'], PHP_URL_PATH),
        "POST",
        $params
    );

    $context = new RequestContext();
    $context->fromRequest($req);
    $route = $this->get('router');
    $matcher = new UrlMatcher($route->getRouteCollection(), $context);

    $dispatcher = new EventDispatcher();
    $dispatcher->addSubscriber(new RouterListener($matcher));
    $resolver = new ControllerResolver();
    $kernel = new HttpKernel($dispatcher, $resolver);

    $response = $kernel->handle($req, HttpKernelInterface::SUB_REQUEST);
    $res[$k] = $response->getContent();
}

Can you give my some hints? Thanks!

Answer 1

Why do you want to make simple task so complex?

In your controller you can just create new Request object and pass it to the existing (already instantiated) HttpKernel instance:

foreach($request_list as $k => $v) {
    parse_str(parse_url($v['url'], PHP_URL_QUERY), $params);
    $req = Request::create(
        parse_url($v['url'], PHP_URL_PATH),
        "POST",
        $params
    );

    $httpKernel = $this->container->get('http_kernel');
    $response = $httpKernel->handle(
        $request,
        HttpKernelInterface::SUB_REQUEST
    );
    $res[$k] = $response->getContent();
}