No, unfortunately, open-sourcing it has been on my to-do list for an embarrassingly long time.
But, building one is easier than it sounds! Think of the problem in two parts. First, find a distro used by multiple providers (we're on CentOS) and craft one script that uses each provider's API to spin up a clean machine.
Once you have that done, it's a matter of understanding your own build process, writing a script that you'll pass into each instance on creation that will fetch your source control, install libraries, and put all the pieces together.
Lots of if/else, lots of curl, lots of yum, lots of jq, but all of it is really straightforward.