Another tool to diff nixos, nix-darwin, etc. configurations

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Hello!

I was greatly inspired by this post Diffing NixOS configurations at the config-level , but sadly the project seems like it hasn’t had much activity since it was first posted. Huge shout out to @oddlama for doing what I’ve wanted for years! I ended up making my own much reduced and simpler version (none of the detailed dependency analysis, only some similar diff functionality, and only uses a pager instead of a proper TUI) here GitHub - kwbauson/configdiff · GitHub .

Notable differences:

  • This is a standalone tool that works directly with flake references, so it should work with nixosConfigurations and homeConfigurations and similar as-is
  • Doesn’t need to patch nix or nixpkgs (just an IFD to use a new evalModules with a small patch)
  • The code is pretty simple (< 500 lines of nix + python) so hopefully easy to maintain and/or hack on if desired

You can test it out and see what happens when services.postgresql.enable = true on the minimal installation cd with this:

nix run github:kwbauson/configdiff github:kwbauson/configdiff?dir=test#nixosConfigurations.{base,postgresql}

diff-postgresql
diff-postgresql1249×439 58.4 KB

You can check test/flake.nix and the github actions workflow for more examples

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