Corley Maintenance Bundle

A unified way of putting a web application under maintenance using web server strategies. The maintenance mode will cut off all requests and it will replies with a static html file and a 503 header (Service Unavailable).

Those conditions will ensure that a load balancer cut an instance off during a maintenance

Install

In composer.json add the requirement. The current version requires at least PHP 7.2 and a supported version of Symfony (3.4, 4.2, 4.3, 4.4 and 5.0).

"require": {
    "corley/maintenance-bundle": "^0.3"
}

To support earlier versions e.g. SF 2.x, 3.3, 4.1 etc or PHP less than 7.2 you will need to use:

"require": {
    "corley/maintenance-bundle": "^0.2"
}

This version can also be used for more recent Symfony versions, e.g. with 3.4 or 4.4 but is not compatible with Symfony 5 - only 0.3 can be used there because of changes to the event structure in Symfony 5.0.

For pre-Flex applications register the bundle in AppKernel.php

public function registerBundles()
{
    ...
    $bundles = array(
        ...
        new Corley\MaintenanceBundle\CorleyMaintenanceBundle(),
    );
    ...
    return $bundles;
}

For projects built with recent versions of Flex, a default recipe will be generated which will add the bundle to your bundles.php. In older versions of Flex you may need to do this yourself

Corley\MaintenanceBundle\CorleyMaintenanceBundle::class => ['all' => true],

Maintenance mode

When you want to put your web application under maintenance

bin/console corley:maintenance:lock on

Restore the application status

bin/console corley:maintenance:lock off

Configure your web server

If you use Apache2 you have to add a few lines to your .htaccess, for nginx just add dedicated lines to web app configuration. Make sure that those lines precede any other rewrite rule. The mod_rewrite module in Apache2 has to be installed and enabled.

In order to obtain your configuration options use the console

Apache2

bin/console corley:maintenance:dump-apache

Nginx

bin/console corley:maintenance:dump-nginx

Configuration

You can configure the bundle in order to change the default behaviour (all options have a default value)

For projects not using Flex

# config.yml
corley_maintenance:
    page: %kernel.root_dir%/../web/maintenance.dist.html
    hard_lock: lock.html
    symlink: false

For Flex projects

# config/packages/corley.yml
corley_maintenance:
    page: %kernel.project_dir%/templates/maintenance.dist.html
    hard_lock: lock.html
    symlink: false

Options:

• page is the original maintenance page (default: vendor/corley/maintenance-bundle/Corley/MaintenanceBundle/Resources/views/maintenance.html)
• symlink If you want to use symlinks instead hardcopy strategy (default: hardcopy)
• hard_lock Is the name used in order to lock the website (default: hard.lock)
• web public folder (default web folder, for Flex projects you will need to configure this for your public folder, i.e. %kernel.project_dir%/public)
• soft_lock Is the name used in order to lock the website (using app layer)
• whitelist Authorized connections [soft-lock only]
  • paths A list of paths that skip the maintenance lock
  • ips A list of ips that skip the maintenance lock

Soft locking

The soft locking strategy uses the php layer in order to lock down the website. This means that the application must work in order to lock down the web site.

The soft lock runs at kernel.request and stops other event propagation.

When you want to put your web application under maintenance using a soft-locking strategy:

bin/console corley:maintenance:soft-lock on

Restore the application status

bin/console corley:maintenance:soft-lock off