Using git to handle and manage `configuration.nix`

[enoren5]

@Damage

I think Nix and NixOS are definitely “do what you want” rather than “do what others do” way of working.

If all NixOS admins handle /etc/nixos/configuration.nix differently - - and no two approaches are the same as you say - - where each individual user approaches administering their configurations like a unique (snow) ‘flake’ - - then I want to learn from as many as possible because the problematic default way that I outlined in my OP above is clearly broken. If everyone is different then that is even a better reason to solicit best practices from others. I don’t intend to copy exactly what someone else does. I just want to explore what options are out there.

I got a symlink arrangement to work with my new GitHub repo.

Here are the steps I used (for my future reference and to help any else out there who may be as curious as I was when I started this thread):

1. Move /etc/nixos/configuration.nix to the locally cloned GitHub repo in the user’s home directory.

   • If you run $ ls -la then you’ll notice the owner and group permission for this file is still set to root.

2. To resolve this, change ownership. In my case in my VBox demo appliance, the user is demo and the group is users. Here is the required command: $ sudo chown demo:users configuration.nix. In prod when I make the leap-of-faith and commit to migrating from my native Manjaro installation to NixOS, the user name will not be ‘demo’. So change accordingly.

   • This is also required: $ chmod +w configuration.nix

3. In /etc/nixos/, run:

    $ sudo ln -s ~/<your-github-repo-name>/configuration.nix .

• To emphasize: take note of the trailing “.” at the end.
• Additional point of clarification: The recommended command #3 here will only work inside /etc/nixos/ as working directory. If you try to complete the symbolic link by invoking the ln -s command from within the repo directory, it won’t work. So be careful with this too.

The end product should look like this:

Now I have userland version control of configuration.nix using git. The advantage is that now when I track every change I make, if I bork the configuration with a syntax error or some other hard to diagnose, I can very easily revert back to the last known working state. Excellent! I am stoked.

If I ever start a fresh install and I clone my repo with, I just need to change directory into /etc/nixos, remove configuration.nix, and then issue the symbolic link command above. All that is left to do is run $ nixos-rebuild switch and it will swap to the config and start building.