A microservice example of a AppKernel

AppKernel.php

<?php

use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
use Symfony\Component\DependencyInjection\Dumper\PhpDumper;
use Psr\Http\Message\RequestInterface;
use Happyr\Geocoder\Middleware\Middleware;
use Relay\RelayBuilder;
use Zend\Diactoros\Response;

class AppKernel
{
    /**
     * @var bool
     */
    private $booted = false;

    /**
     * @var bool
     */
    private $debug;

    /**
     * @var \Symfony\Component\DependencyInjection\Container
     */
    private $container;

    /**
     * Kernel constructor.
     *
     * @param $debug
     */
    public function __construct($debug = false)
    {
        $this->debug = $debug;
    }

    /**
     * Handle a Request and turn it in to a response.
     *
     * @param Request $request
     *
     * @return Response
     */
    public function handle(RequestInterface $request)
    {
        $this->boot();

        $relayBuilder = new RelayBuilder();
        $relay = $relayBuilder->newInstance([
            Middleware::newrelic(),
            $this->container->get('middleware.cache_lookup'),
            Middleware::queryParser(),
            Middleware::router($this->container),
            $this->container->get('middleware.cache'),
        ]);

        return $relay($request, new Response());
    }

    /**
     * Load the container.
     */
    public function boot()
    {
        if ($this->booted) {
            return;
        }

        $containerDumpFile = __DIR__.'/../app/cache/container.php';
        if (!$this->debug && file_exists($containerDumpFile)) {
            require_once $containerDumpFile;
            $container = new CachedContainer();
        } else {
            $container = new ContainerBuilder();
            $container->setParameter('root_dir', dirname(__DIR__));
            $loader = new YamlFileLoader($container, new FileLocator(__DIR__.'/../app/'));
            $loader->load('services.yml');

            if ($this->debug) {
                $container->setAlias('cache', 'cache.void');
            }

            $container->compile();

            if (!$this->debug) {
                //dump the container
                $dumper = new PhpDumper($container);
                file_put_contents($containerDumpFile, $dumper->dump(array('class' => 'CachedContainer')));
            }
        }

        $this->container = $container;

        $this->booted = true;
    }
}