In his latest post Andreas Gohr shares a platform he's developed using docker to create a multi-PHP version instance that can run locally with just a few commands.
Yesterday I tried to fix a bug a user had reported in one of my DokuWiki plugins. Apparently it only occurred on PHP 5.2. Well, the last PHP 5.2 version was released in 2011 and no modern distribution has it anymore. So how do I test this easily? After a few failed attempts with finding a virtual machine image that would give me the needed PHP version I decided to come up with my own solution. And because I was curious - I decided to build it on docker.
He's already done the hard work for you and created the "phpfarm" project that's easy to pull in and use. He includes the two commands to get it downloaded and up and working and running PHP versions 5.2 through 5.5 on ports 8052 to 8055. If you're interested in seeing his Dockerfile, check it out on Github.