Setting up a realistic, multi-machine environment on your own laptop used to mean juggling VirtualBox windows, clicking through installers, and hoping you could reproduce the same setup tomorrow. Vagrant replaces all of that with a single text file. In this article we'll build a three-machine lab, two Ubuntu web servers and one CentOS database server, wired together on a private network, with the database node automatically provisioned at boot. By the end you'll understand not just what ...