Develop microservices
in PHP

by Enrico Zimuel
Senior Software Engineer
Rogue Wave Software Inc.

Codemotion 2018, Milan (Italy), 30th Nov

About me

Developer since 1996 Senior Software Engineer at Rogue Wave Software Inc. Open source contributor Apigility, Expressive and Zend Framework TEDx and international speaker Professor at ITS-ICT Piemonte and Research Programmer at Amsterdam University Co-founder of PUG Torino (Italy)

Book: Sviluppare in PHP 7

www.sviluppareinphp7.it pp. 352, Tecniche Nuove, 2017 ISBN 978-88-481-3120-9 in Italian

Microservice

...the microservice architectural style is an approach to developing a single application as a suite of small services, each running in its own process and communicating with lightweight mechanisms, often an HTTP resource API

- Martin Fowler

Source: Introduction to microservices

Source: Introduction to microservices

Benefit

• Separation of concerns
  • Modularity
  • Encapsulation
• Scalability
  • Horizontally scaling
  • Workload partitioning

Cons

• Network latency
• Debugging
• New architecture challenges:
  • Autodiscovery
  • Telemetry
  • Everything needs to be automated

PHP

Microservices in PHP

• PHP is easy to deploy
• PHP 7 is super fast!
• Big community
• Libraries/Frameworks
• Async in PHP (Swoole, ReactPHP, ...)

The PHP framework for middleware applications

• PSR-7 support (using zend-diactoros)
• PSR-15 support and piping workflow (using zend-stratigility)
• Features: routing, dependency injection, templating, error handling
• Support of Swoole out-of-the-box

A basic web API

use Zend\Diactoros\Response\JsonResponse;
use Zend\Expressive\Application;

$container = require 'config/container.php';

$app = $container->get(Application::class);
$app->pipe('/api/ping', function($request) {
    return new JsonResponse(['ack' => time()]);
});
// $app->pipe('/api/ping', \App\Handler\PingHandler::class);
$app->run();

Request Handler

use Psr\Http\Message\ResponseInterface as Response; // PSR-7
use Psr\Http\Message\ServerRequestInterface as Request; // PSR-7
use Psr\Http\Server\RequestHandlerInterface as Handler; // PSR-15
use Zend\Diactoros\Response\JsonResponse;

class PingHandler implements Handler
{
    public function handle(Request $request) : Response
    {
        return new JsonResponse(['ack' => time()]);
    }
}

Middleware

Middleware

Example: Authentication

use Psr\Http\Server\MiddlewareInterface; // PSR-15

class AuthMiddleware implements MiddlewareInterface
{
  public function process(Request $request, Handler $handler): Response
  {
    $user = $this->auth->authenticate($request);
    if (null !== $user) {
      return $handler->handle($request->withAttribute(
        UserInterface::class,
        $user
      ));
    }
    return $this->auth->unauthorizedResponse($request);
  }
}

Example: Routing REST API

$app->route('/api/users[/{id}]', [
    Authentication\AuthenticationMiddleware::class,
    Authorization\AuthorizationMiddleware::class,
    Api\Action\UserAction::class
], ['GET', 'POST', 'PATCH', 'DELETE'], 'api.users');

// or route each HTTP method
$app->get('/api/users[/{id}]', ..., 'api.users.get');
$app->post('/api/users', ..., 'api.users.post');
$app->patch('/api/users/{id}', ..., 'api.users.patch');
$app->delete('/api/users/{id}', ..., 'api.users.delete');

Quick start

You can start using Expressive with composer:

composer create-project zendframework/zend-expressive-skeleton <dir>

Libraries for API

• HAL-JSON: zend-expressive-hal
• Problem details: zend-problem-details
• Filtering & validation: zend-inputfilter
• Authentication (HTTP Basic, OAuth2): zend-expressive-authentication
• Authorization (ACL, RBAC): zend-expressive-authorization

Swoole

• Swoole is an async programming framework for PHP 7
• PHP extension, install:

  
  pecl install swoole
  

• Released under Apache license 2.0
• More info at swoole.co.uk

Features

• Event-driven, asynchronous programming for PHP
• Async TCP / UDP / HTTP / Websocket / HTTP2 client/server side API
• IPv4 / IPv6 / Unixsocket / TCP/ UDP and SSL / TLS support
• High performance and scalable
• Fast serializer / unserializer
• Milliseconds task scheduler

Swoole vs. PHP-FPM

• Forks a number of worker processes based on CPU core number
• Fupports Long-live connections
• Manage and reuse the status in memory
• Executes Non-blocking code (async, coroutine)

HTTP Server

use Swoole\Http\Server;

$http = new Server("127.0.0.1", 9501);

$http->on("start", function ($server) {
    echo "Started at http://127.0.0.1:9501\n";
});
$http->on("request", function ($request, $response) {
    $response->header("Content-Type", "text/plain");
    $response->end("Hello World\n");
});

$http->start();

Test: 16K req/sec on CPU i5-2500, 16 GB RAM, PHP 7.2.12, Swoole 4.2.9

Expressive with Swoole

Install:

composer require zendframework/zend-expressive-swoole

Usage:

vendor/bin/zend-expressive-swoole start

Open your browser at localhost:8080

PHP + Expressive + Swoole

Run a web application from CLI

Simplify the deploy (only 1 container)

A web server (nginx) can be used as load balancer

Benchmark

2-4x faster than Nginx and Apache

Testing environment:
Ubuntu 18.04, Expressive Skeleton 3.2.3, PHP 7.2.12, Nginx 1.14 + FPM,
Apache 2.4.29 + mod_php, Swoole 4.2.9, CPU i5-2500, 16 GB RAM, HD SSD

References

Thanks!

Contact me: enrico.zimuel (at) roguewave.com

Follow me: @ezimuel

This work is licensed under a
Creative Commons Attribution-ShareAlike 3.0 Unported License.
I used reveal.js to make this presentation.