nixosTest with flake configurations

1

I am trying to write some integration tests for my machines in a flake.nix, however I seem to have run into an issue. The nixosTest function and underlying make-test-python.nix seem to expect a nixos module, but the flakes nixosConfigurations output wants a system that has already been evaluated by eval-config.nix.

I’ve tried:

nixosTest { machine = self.nixosConfigurations.NixOS; }
nixosTest { machine = self.nixosConfigurations.NixOS.config; }
nixosTest { machine = self.nixosConfigurations.NixOS.config.system.build.toplevel; }
nixosTest { machine = self.nixosConfigurations.NixOS.config.system.build.vm; }

to no avail.

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3

I don’t think you can do it at this level. However you can have your nixos modules list in variable and pass it to both nixosSystem { modules = myModules; } and nixosTest { nodes.machine = {...}: { imports = myModules;};}

2 Likes
4

Indeed, I already knew I had to generalize hosts. Dumb question but I’m glad it has an answer for anyone as stupid as me :+1:

5

If anyone is interested I created an issue here Use different versions of nixpkgs for the nodes than the one used for the nixos test · Issue #195600 · NixOS/nixpkgs · GitHub.

6

I tried following your advice, but I run into an infinite recursion which I don’t fully understand, which I believe is related to access to config._module.args.

Any suggestions for how to test a nixosConfiguration with the testing framework?

7

Ive been down this rabbit hole myself and recently found a solution that fits my needs similar to you. Below is a link to a function that builds a nixosTest. I hope it helps and let me know if you are confused as to what is going on below.

function:

toplevels required:

Usage: