Zend Strategility + FastRoute - lean microservice approach

index.php

<?php
declare(strict_types = 1);

use \Psr\Http\Message\ServerRequestInterface as Request;
use Psr\Http\Message\ResponseInterface as Response;

chdir(dirname(__DIR__));

require 'vendor/autoload.php';

$app = new \Zend\Stratigility\MiddlewarePipe();

$app->pipe('/api/v1', function (Request $req, Response $res, callable $next) {
    /** @var FastRoute\Dispatcher $router */
    $router = require 'app/config/router.php';

    /** @var \Interop\Container\ContainerInterface $container */
    $container = require 'app/config/container.php';

    $route = $router->dispatch($req->getMethod(), $req->getUri()->getPath());

    if ($route[0] === FastRoute\Dispatcher::NOT_FOUND) {
        return $res->withStatus(404);
    }

    if ($route[0] === FastRoute\Dispatcher::METHOD_NOT_ALLOWED) {
        return $res->withStatus(405);
    }

    foreach ($route[2] as $name => $value) {
        $req = $req->withAttribute($name, $value);
    }

    $httpHandler = $container->get($route[1]);

    return $httpHandler($req, $res);
});

$app->pipe('/', function ($req, $res, $next) {
    return new \Zend\Diactoros\Response\TextResponse('It works');
});

//Register simple error handler (don't use it in production!!!)
$app->pipe(function($err, $req, $res, $next) {
    if ($err instanceof \Throwable) {
        return new \Zend\Diactoros\Response\TextResponse((string)$err, 500);
    }
});

$server = \Zend\Diactoros\Server::createServer(
    $app,
    $_SERVER,
    $_GET,
    $_POST,
    $_COOKIE,
    $_FILES
);

$server->listen();

router.php

<?php

declare(strict_types = 1);

return \FastRoute\simpleDispatcher(function(\FastRoute\RouteCollector $r) {
    $r->addRoute(
        'PUT',
        '/companies/{company:\d+}/customers/{client_id:\d+}',
        \Acme\CustomersWrite\Http\ImportBasicCustomerDataAction::class
    );
});