Your next Web server will be written in... PHP

Presentation at International PHP Conference 2017 Spring Edition in Berlin, Germany.

1. YOUR NEXT WEB SERVER WILL BE WRITTEN IN... PHP MIGHT International PHP Conference 2017 (Spring Edition) Berlin, Germany
2. David Zuelke
4. dz@heroku.com
5. @dzuelke
6. Slides: https://speakerdeck.com/dzuelke/
7. CGI
8. NCSA, 1993
10. RFC 3875, 1997-2004
12. /cgi-bin/counter.pl?site=8712
15. HOW CGI WORKS 1. Web server parses request from client 2. Web server sets request info into environment
 (PATH_INFO, REQUEST_METHOD, HTTP_ACCEPT, …) 3. Web server executes CGI script 4. CGI script echos status, headers, and body 5. Web server returns response to client
16. slow
17. (but simple)
18. #!/bin/bash cat <<EOF Content-Type: text/html <html> <head> <title>Hello World</title> </head> <body> <h1>Hello World</h1> <p>Your browser is ${HTTP_USER_AGENT:-unknown}</p> <p>This page was served by $(hostname)</p> </body> </html> EOF
19. CGI VARIABLES (SEE $_SERVER) • Server info:
 SERVER_SOFTWARE, SERVER_NAME, GATEWAY_INTERFACE • Request info:
 SERVER_PROTOCOL, SERVER_PORT, REQUEST_METHOD, PATH_INFO, PATH_TRANSLATED, QUERY_STRING, REMOTE_ADDR, CONTENT_TYPE, CONTENT_LENGTH, … • Request headers:
 HTTP_HOST, HTTP_ACCEPT, HTTP_USER_AGENT, …
20. PHP's SAPIs
 & EXECUTION MODEL
21. a SAPI is the "gateway" to the PHP engine
22. marshals input and output from and to the interface
23. PHP WEB SAPI (SIMPLIFIED) • populate $_SERVER and $_ENV • parse QUERY_STRING into $_GET • " application/x-www-form-urlencoded into $_POST • " multipart/form-data into $_FILES • return header() data as headers, anything echo()d as content
24. PHP was built for web scripting, for CGI
25. execution model modeled around statelessness "blank slate"
26. PHP CGI EXECUTION LIFECYCLE
 (SIMPLIFIED) 1. core init, load extensions etc 2. MINIT for all modules (extension initialization etc) 3. SAPI ready for (one and only) request 4. RINIT for all modules (e.g. ext-session if session.auto_start) 5. script executes 6. RSHUTDOWN 7. engine cleanup (unset all variables and state) 8. MSHUTDOWN
27. all of that on each CGI request
28. NEIN NEIN NEIN NEIN DAS IST ZU LANGSAM
29. mod_php
30. embeds PHP into the Apache httpd process
31. mod_php EXECUTION LIFECYCLE
 (SIMPLIFIED) 1. SAPI ready for (next) request 2. RINIT for all modules (e.g. ext-session if session.auto_start) 3. script executes 4. RSHUTDOWN 5. engine cleanup (unset all variables and state)
32. but now PHP is in each httpd process
33. even when serving static files
34. APACHE PROCESS MODELS • mpm_prefork creates worker processes
 (each with a PHP) • mpm_worker uses threads
 (so you need ZTS, and stuff will generally crash a lot) • mpm_event uses an event loop
 (best, but you can't embed something like PHP at all)
35. so... what do we do?
36. ¯\_(ツ)_/¯
37. "let's just use Nginx!"
38. FastCGI
39. protocol similar to CGI, but over a socket
40. persistent server process
41. old fcgi SAPI: web server manages FastCGI child processes
42. newer FPM: PHP manages its own child processes' lifecycle
43. no overhead in web server for static content
44. web server can use threading or whatever
45. still re-executes from ~RINIT for each request
46. still bootstraps Symfony/Laravel/… on each request
47. RUBY & PYTHON
48. Rack & WSGI
49. RUBY/RACK app = Proc.new do |env| ['200', {'Content-Type' => 'text/plain'}, ['Hello World']] end def application(environ, start_response): start_response('200 OK', [('Content-Type', 'text/plain')]) yield 'Hello World\n' PYTHON/WSGI
50. THE RACK/WSGI STACKS 1. Web server:
 Unicorn, Gunicorn, Puma, Tornado, Nginx with Phusion Passenger, Apache with mod_wsgi, ... 2. Middlewares:
 Routing, authentication, filtering, post-processing, ... 3. Application/framework:
 Rails, Django, Sinatra, Flask, ...
51. NATIVE PHP WEB SERVERS
52. PHP IS NOW READY • PHP 7+ performance is amazing • Almost all engine errors are catchable since PHP 7 • Signal handling without ticks in PHP 7.1 • Concurrency frameworks and event lib extensions
53. FRAMEWORKS FOR EVENT- DRIVEN NON-BLOCKING I/O • http://reactphp.org • https://icicle.io • http://amphp.org
54. IT'S ALL A REACTOR echo "-- before run()\n"; Amp\run(function() { Amp\repeat(function() { echo "tick\n"; }, $msInterval = 1000); Amp\once("Amp\stop", $msDelay = 5000); }); echo "-- after run()\n";
55. SIMPLE WEB SERVER, ReactPHP $app = function ($request, $response) { $response->writeHead(200, array('Content-Type' => 'text/plain')); $response->end("Hello World\n"); }; $loop = React\EventLoop\Factory::create(); $socket = new React\Socket\Server($loop); $http = new React\Http\Server($socket, $loop); $http->on('request', $app); $socket->listen(1337); $loop->run();
56. https://github.com/M6Web/PhpProcessManagerBundle & https://github.com/php-pm/php-pm
57. $kernel = new AppKernel('prod', false); $reactHttp->on('request', function ($request, $response) use ($kernel) { $headers = $request->getHeaders(); if (in_array(strtoupper($request->getMethod()), ['POST','PUT','DELETE','PATCH']) && isset($headers['Content-Type']) && (0 === strpos($headers['Content-Type'], 'application/x-www-form-urlencoded')) ) parse_str($request->getBody(), $post); $sfRequest = new Symfony\Component\HttpFoundation\Request( $request->getQuery(), // query string $post ?? [], // parsed POST payload array(), // attributes (PATH_INFO etc) array(), // $_COOKIES $request->getFiles(), // $_FILES array(), // $_SERVER $request->getBody() // raw request body ); $sfRequest->setMethod($request->getMethod()); $sfRequest->headers->replace($headers); $sfRequest->server->set('REQUEST_URI', $request->getPath()); if (isset($headers['Host'])) $sfRequest->server->set('SERVER_NAME', explode(':', $headers['Host'])[0]); $sfResponse = $kernel->handle($sfRequest); $response->writeHead($sfResponse->getStatusCode(), $sfResponse->headers->all()); $response->end($sfResponse->getContent()); $kernel->terminate($request, $response); });
58. WHAT BECOMES POSSIBLE
59. speeeeeeeeeed :)
60. http://marcjschmidt.de/blog/2014/02/08/php-high-performance.html
61. processing request data while it's still uploading
62. handling Web Sockets in the same process
63. git clone project && cd project && composer install && php server.php
64. WHAT BECOMES IMPOSSIBLE
65. native session handling
66. ignoring memory leaks
67. MAYBE, IN A BRIGHT FUTURE...
68. PSR-7 (HTTP Message Interface) + PSR-15 (HTTP Middlewares) = ultimate interop :)
69. a universe of useful middlewares :)
70. competition between different native web servers :)
71. "legacy" server that runs in FPM SAPI and translates a request :)
72. "legacy" middleware that runs in new server and populates $_GET and friends :)
73. READING MATERIAL • https://gnugat.github.io/2016/04/13/super-speed-sf-react-php.html • http://blog.kelunik.com/2015/09/20/getting-started-with-amp.html • http://blog.kelunik.com/2015/10/21/getting-started-with-aerys.html • http://blog.kelunik.com/2015/10/20/getting-started-with-aerys- websockets.html • http://marcjschmidt.de/blog/2014/02/08/php-high-performance.html • http://marcjschmidt.de/blog/2016/04/16/php-high-performance-reactphp- jarves-symfony-follow-up.html
74. The End
75. THANK YOU FOR LISTENING! Questions? Ask me: @dzuelke & dz@heroku.com