caxy/appengine-bridge

Components to support Symfony components in Google App Engine

dev-master / 1.0.x-dev 2015-04-19 21:33 UTC

MIT

• Benjamin Doherty

README

This package supports Symfony and related components on Google App Engine.

Features

• Monolog handler specifically for App Engine's simple syslog() facility.
• Pimple service provider for running Silex on App Engine.
• Abstract kernel base class that sets cache and log directories for App Engine.
• This README.

Installation

Add to composer.json:

{
    "repositories": [
        {
            "type": "vcs",
            "url": "https://github.com/caxy/AppEngineBridge.git"
        }
    ],
    "require": {
        "caxy/appengine-bridge": "~1.0@dev"
    }
}

Silex

Register the AppEngineProvider after your other providers have been registered.

<?php
$app->register(new \Caxy\AppEngine\Bridge\Pimple\Provider\AppEngineProvider());

Make sure that the php55 runtime is set in your app.yaml or else Silex will fail because tempnam() support is only in php55.

Symfony

Use the Google App Engine configuration file app.yaml to set environment variables. Using the php55 runtime is required. The SYMFONY__APP_ENGINE__DEFAULT_BUCKET_NAME value becomes a container parameter and is used to set up cache and log directories. Here is a work-in-progress example:

application: SOMETHING
version: 1
runtime: php55
api_version: 1
threadsafe: true

handlers:
- url: /bundles
  static_dir: web/bundles
- url: .*
  script: web/app.php

skip_files:
- ^(.*/)?#.*#$
- ^(.*/)?.*~$
- ^(.*/)?.*\.py[co]$
- ^(.*/)?.*/RCS/.*$
- ^(.*/)?\..*$
- ^(.*/)?.*/Tests/.*$
- var/cache/*
- var/logs/*

env_variables:
  SYMFONY_ENV: prod
  SYMFONY_DEBUG: 0
  SYMFONY__APP_ENGINE__DEFAULT_BUCKET_NAME: 'SOMETHING.appspot.com'

Replace your front controller entirely so you can switch between environments using the app.yaml environment variable. The example here is a combination of Symfony framework Standard Edition's app.php and app_dev.php.

<?php

use Symfony\Component\ClassLoader\ApcClassLoader;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Debug\Debug;

$loader = require_once __DIR__.'/../var/bootstrap.php.cache';
if ((bool) $_SERVER['SYMFONY_DEBUG']) {
    Debug::enable();
}

// Enable APC for autoloading to improve performance.
// You should change the ApcClassLoader first argument to a unique prefix
// in order to prevent cache key conflicts with other applications
// also using APC.
/*
$apcLoader = new ApcClassLoader(sha1(__FILE__), $loader);
$loader->unregister();
$apcLoader->register(true);
*/

require_once __DIR__.'/../app/AppKernel.php';
//require_once __DIR__.'/../app/AppCache.php';

$kernel = new AppKernel($_SERVER['SYMFONY_ENV'], (bool) $_SERVER['SYMFONY_DEBUG']);
$kernel->loadClassCache();
//$kernel = new AppCache($kernel);

// When using the HttpCache, you need to call the method in your front controller instead of relying on the configuration parameter
//Request::enableHttpMethodParameterOverride();
$request = Request::createFromGlobals();
$response = $kernel->handle($request);
$response->send();
$kernel->terminate($request, $response);

Replace the Kernel that your AppKernel extends.

diff --git a/app/AppKernel.php b/app/AppKernel.php
index 7673684..0d03d5a 100644
--- a/app/AppKernel.php
+++ b/app/AppKernel.php
@@ -1,6 +1,6 @@
 <?php
 
-use Symfony\Component\HttpKernel\Kernel;
+use Caxy\AppEngine\Bridge\HttpKernel\Kernel;
 use Symfony\Component\Config\Loader\LoaderInterface;
 
 class AppKernel extends Kernel

Establish memcache session handler. In app/config/services.yml:

services:
    session.memcache:
        class: Memcache

    session.handler.memcache:
        class:     Symfony\Component\HttpFoundation\Session\Storage\Handler\MemcacheSessionHandler
        arguments: [ @session.memcache ]

The Symfony profiler can store data in Memcached too. The specific host and port of this DSN are not important as GAE supplies its own PHP Memcache object.

framework:
    profiler:
        dsn: 'memcache://localhost:11211'

Use the syslog Monolog handler. The ident value is unimportant but required for Symfony to instantiate the handler:

monolog:
    handlers:
        main:
            type:         fingers_crossed
            action_level: debug
            handler:      syslog
        syslog:
            type: syslog
            ident: whatever

Features to do

• Easily purge Symfony cache on GAE.
• Build the application without developer dependencies prior to updating.

Other Niceties

In your composer.json add a new scripts entry so that you can deploy easily from composer.

{
    "scripts": {
        "appengine-update": [
             "appcfg.py update . --oauth2"
        ]
    }
}

Now you can deploy with the command composer appengine-update. Additional commands can be stacked together.

{
    "scripts": {
        "appengine-update": [
             "composer dumpautoload -o",
             "appcfg.py update . --oauth2"
        ]
    }
}