Your Drupal site is not a stand-alone application. It relies on a number of other components to function: the operating system, web server, a database, and PHP interpreter, just for starters. As your site grows, the infrastructure supporting it often becomes more complex, involving automated backups, database replication, network filesystems, queues, and more. Each of these components must be properly installed, configured, managed, and upgraded over time.

With the rise of configuration management systems like Puppet and Chef, server configuration is now software. Like all software, server configuration needs constant automated testing in order to work, but testing infrastructure-as-software is a substantially different problem from testing normal application software.

In this talk, I'll describe some of the techniques Acquia Cloud uses to automate its infrastructure testing, enabling releases multiple times per day to thousands of servers on EC2.