Revision of Setting up a Platform from Thu, 10/28/2010 - 01:02

What is a platform anyway?

Platforms are a type of node in Aegir and often the source of confusion for new users. This is because the term or concept isn't really used explicitly outside of Aegir - Aegir is a system that suddenly makes Platforms 'make sense' to have.

The simplest definition of a Platform is a copy of Drupal core. That's really it. When you download a copy of Drupal from drupal.org, the result is what Aegir thinks of as a 'Platform'. No sites exist on it yet.

Before you can create a site using Aegir, you must first define the Platform. This tells Aegir where to store the site directory, settings.php etc on the system.

In short: first you create a Platform, and a site 'lives' on that platform, in exactly this fashion:

• drupal-6.19 (Platform)
  • /sites/yoursite.com/settings.php (site)

This abstraction is somewhat unique to Aegir in that it opens up a world of new opportunities for you. By managing Platforms or copies of Drupal core, and understanding what sites are on what copy of core, Aegir is capable of moving sites between platforms (which is effectively upgrading a site) - read more about this in Migrating/upgrading and renaming sites.

What else could be considered a platform?

Anything that is more or less a copy of Drupal core is something Aegir considers a 'platform'. This thus includes any Drupal distribution, such as OpenAtrium, Pressflow, Acquia Drupal, OpenPublish, ManagingNews, and so on.

The key difference between such distributions and a standard 'vanilla' copy of Drupal core is that these distributions tend to have * a custom install profile in the /profiles/ directory * a set of contrib or custom developed modules, libraries or themes shipped with the core or profile

If you build a copy of Drupal core and place your custom install profile in /profiles, this could be considered a Platform.

If you place your custom install profile in an existing Platform and re-Verify the Platform, that profile will now be recognised as an option when creating a site on that Platform.

Various 'versions' of Drupal, such as Drupal 5.x, Drupal 6.x or Drupal 7.x, are all considered separate Platforms in Aegir.

Drupal 4.x is not supported in Aegir.

Is this paradigm clear? 'Sites' are managed inside 'Platforms'. 'Platforms' are managed inside 'Servers'. 'Servers' are managed by Aegir. In this sense, Aegir manages all the rest too.

Adding a Platform

A number of techniques exist to put a platform on a server.

Drush

For a standard Drupal platform, the easiest is to simply use drush:

Wget

You can simply use the 'wget' command, for example:

Version control

You could use CVS, eg:

Manually

You could download it on your PC and scp or FTP the files up onto your server.

Drush Make

Drush Make comes installed on your Aegir system by default. You can use Drush Make to 'build' a platform, which does the job of fetching core and any other contributed or custom packages that you specify in a makefile.

You can even specify the URL or path to a makefile in the form you are given when adding a Platform node in the Aegir frontend, and Aegir will execute the Drush Make command in the backend and build it for you!

Explaining how to use Drush Make is outside the scope of this document. Consult the README.txt of Drush Make to learn the makefile syntax, or use a ready-made makefile available from the web. Some distributions such as OpenAtrium provide an example makefile for you to build the distribution with.

Do I have to have multiple platforms on my Aegir?

No, you can simply have one platform or copy of Drupal core and provision all your sites to sit on the one platform. However, eventually you will want to upgrade your sites to a new copy of Drupal core, and rather than replace your core files in-place, it's recommended to build a new Platform with the newer copy of core, and use the Migrate task to move your sites (upgrade) onto the new code.