Redirect to SSL only on given

services.yml

services:
  ssl_manager.listener:
    class: SSLManagementListener
    arguments: [ 'example.com' ]
    tags:
      - { name: kernel.event_listener, event: kernel.request, method: onKernelRequest }

SSLManagementListener.php

<?php

use Symfony\Component\HttpFoundation\RedirectResponse;
use Symfony\Component\HttpKernel\Event\GetResponseEvent;
use Symfony\Component\HttpKernel\HttpKernel;

class SSLManagementListener
{
    private $domain;

    public function __construct($domain)
    {
        $this->domain = strtolower($domain);
    }

    public function onKernelRequest(GetResponseEvent $event)
    {
        if (HttpKernel::MASTER_REQUEST != $event->getRequestType()) {
            return;
        }

        $request = $event->getRequest();

        if (strtolower($request->getHost()) == $this->domain && strtolower($request->getScheme()) != 'https')
        {
            $response = new RedirectResponse('https://'.$request->getHost().$request->getRequestUri(), 302);
            $event->setResponse($response);
        }
    }
}