feat(dotenv): allow passing full paths to dotenv files

[alirezamirsepassi]

This pull request enables the dotenv integration to accept full paths to the dotenv files. Additionally, I've changed the option filename to files and moved the normalize function to the option itself using lib.toList. I've also added a warning regarding the updated option name to prevent users from breaking their environments.

P.S. I chose to use config.devenv.root instead of self because self evaluates to the nix store source tree when used in a flake configuration. Since dotenv files are typically not committed to a git repository, they won't be present after the copy.

[shyim]

I don't think allowing any path is good. This would make it more hard to remove impure nix mode, as we can access files outside of our project 🤔

Aren't relative paths fine inside your project 🤔

[alirezamirsepassi]

Thanks for your response, I appreciate it. I agree with your point of view, but after doing some research, I found out that flakes copy the source to Nix store before evaluating it, and there's no way around this. As a result, using a git ignored dotenv file is impossible. 😭

Nevertheless, I do think that allowing users to choose the dotenv file path, even if it's outside of the project, is a great idea as it provides more flexibility. For example, I often have variables that I need to share across multiple projects, and a single dotenv file can be used for this purpose.

Aren't relative paths fine inside your project

No, as I mentioned the dotenv file is in my .gitignore file and it's not being copied to the nix store unfortunately

wdyt? 🤔

[shyim]

The project should not be copied into nix store with devenv provided nix 🤔 . But yes the gitignore has an effect 😓 .

Maybe we find a general solution to .gitignore, because of other issues like #1078

[alirezamirsepassi]

How does the devenv CLI create the shell btw? 🤔 I'm not very familiar with rust honestly but what I understood from here, is it runs nix develop with some options and arguments, right? 🤔 does it copy ignored files as well?

[shyim]

You stay in your local normal copy where you did run devenv shell. I am right now looking if to improve this 😅

[alirezamirsepassi]

@domenkozar hi there!

I saw that you changed config.devenv.root to self in the rewrite in rust project, this, unfortunately, breaks my environments where I use flakes as I mentioned in the original description of this PR. Do you happen to know the command that devenv runs to create the shell? Maybe including that command in the .envrc file along with the flakes template would make sense as in: currently the dotenv integration doesn't work in combination with flakes. wdyt? 🤔

[mschnee]

Also confirmed that the rust rewrite has broken dotenv support in devenv when using flakes. For now, I'm using the python-rewrite branch.

flake-test via ❄ impure (devenv-shell-env) …
➜ direnv reload
direnv: loading ~/Projects/flake-test/.envrc
direnv: loading https://raw.githubusercontent.com/nix-community/nix-direnv/2.2.1/direnvrc (sha256-zelF0vLbEl5uaqrfIzbgNzJWGmLzCmYAkInj/LNxvKs=)
direnv: using flake . --impure
direnv: nix-direnv: renewed cache
💡 The dotenv file '.env' was not found.

Using the default flake created by nix flake init --template github:cachix/devenv as documented here.

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
    systems.url = "github:nix-systems/default";
    devenv.url = "github:cachix/devenv";
    devenv.inputs.nixpkgs.follows = "nixpkgs";
  };

  nixConfig = {
    extra-trusted-public-keys = "devenv.cachix.org-1:w1cLUi8dv3hnoSPGAuibQv+f9TZLr6cv/Hm9XgU50cw=";
    extra-trusted-substituters = "https://devenv.cachix.org";
  };

  outputs = { self, nixpkgs, devenv, systems, ... } @ inputs:
    let
      forEachSystem = nixpkgs.lib.genAttrs (import systems);
    in
    {
      packages = forEachSystem (system: {
        devenv-up = self.devShells.${system}.default.config.procfileScript;
      });

      devShells = forEachSystem
        (system:
          let
            pkgs = nixpkgs.legacyPackages.${system};
          in
          {
            default = devenv.lib.mkShell {
              inherit inputs pkgs;
              modules = [
                {
                  dotenv.enable = true;
                  # https://devenv.sh/reference/options/
                  packages = [ pkgs.hello ];

                  enterShell = ''
                    hello
                  '';

                  processes.run.exec = "hello";
                }
              ];
            };
          });
    };
}

Temporary Solution for Flakes
Use the python-rewrite branch (shrug)

inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-23.11";
    systems.url = "github:nix-systems/default";
    devenv.url = "github:cachix/devenv/python-rewrite";
    devenv.inputs.nixpkgs.follows = "nixpkgs";
  };

[domenkozar]

@shyim can you try using this PR to see if it addresses #257

[shyim]

We don't use dotenv module and I don't see it why it should improve the performance 🤔

[domenkozar]

It would still evaluate self that should be impacting the performance

[domenkozar]

This breaks on devenv with:

       error:
       error: A definition for option `dotenv.files."[definition 1-entry 1]"' is not of type `path'. Definition values:
       - In `/nix/store/virtual0000000000000000000000007-source/src/modules/integrations/dotenv.nix': ".env"

because the semantics of the paths are different, I'll think about it how to properly integrate it.

[alirezamirsepassi]

Hey @domenkozar

Thanks for your reply.

IMO, the path type isn't very important for the module and it can be switched back to a simple string as the file path will be verified to exist later in the module using pathExists anyway.

On second thought, we might not even want to have the path type as it will be copied to the Nix store if I'm not mistaken and it might contain some secrets that can't be managed directly/easily on the machine which later can be extracted by others. 🤔

let me know what you think. 🙏🏻

[alirezamirsepassi]

@domenkozar I switched the type back to string and wrapped the default value in a double quotation to avoid nix copying it to the store.

Could you try again on devenv, please?

[alirezamirsepassi]

@domenkozar any updates on this?

[domenkozar]

Thanks for the ping, CI is running

[domenkozar]

nix build
PATH=$PWD/result/bin:$PATH ./result/bin/devenv-run-tests --only dotenv tests

I get

error: string '.env' doesn't represent an absolute path