Leveraging NixOS Tests in your Project
NixOS contains infrastructure for building integration tests based on QEMU/KVM virtual machines running NixOS. Tests built on this infrastructure are continuously run on new nixpkgs versions to ensure that NixOS continues to install and boot and that various services continue to operate correctly. This post illustrates how one may test a simple web service using NixOS tests. To have a simple enough example at hand, we wrote a small service in PHP—a classical guestbook in which visitors can leave a message that will then be written to a database and subsequently shown to later visitors of the same site.