I like to apply Test Driven Development to my sysadmin work. For example, every time I add a new redirect to a web server configuration I want to make sure I haven’t broken anything else. Further, I want my SSL configurations proactively checked daily for any possible error. I use Ruby RSpec and write tests like these:







When I want to make a configuration change, I first write a test for the desired outcome. Naturally, it fails while the old tests pass. I then work on the config change, re-running all the tests as I go, and am finished when they all pass. I also run these automatically from a cron job to get pro-active notification of new problems.

The phrases such as have_a_valid_cert are custom RSpec matchers; they’re added into the RSpec environment by this open source library on Github. I’m also working on an app to run these specs in the cloud.

See also