nixos-mailserver/flake.nix

{
  description = "A complete and Simple Nixos Mailserver";

  inputs = {
    flake-compat = {
      # for shell.nix compat
      url = "github:edolstra/flake-compat";
      flake = false;
    };
    git-hooks = {
      url = "github:cachix/git-hooks.nix";
      inputs.flake-compat.follows = "flake-compat";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    nixpkgs-24_11.url = "github:NixOS/nixpkgs/nixos-24.11";
    blobs = {
      url = "gitlab:simple-nixos-mailserver/blobs";
      flake = false;
    };
  };

  outputs = { self, blobs, git-hooks, nixpkgs, nixpkgs-24_11, ... }: let
    lib = nixpkgs.lib;
    system = "x86_64-linux";
    pkgs = nixpkgs.legacyPackages.${system};
    releases = [
      {
        name = "unstable";
        nixpkgs = nixpkgs;
        pkgs = nixpkgs.legacyPackages.${system};
      }
      {
        name = "24.11";
        nixpkgs = nixpkgs-24_11;
        pkgs = nixpkgs-24_11.legacyPackages.${system};
      }
    ];
    testNames = [
      "clamav"
      "external"
      "internal"
      "ldap"
      "multiple"
    ];

    genTest = testName: release: let
      pkgs = release.pkgs;
      nixos-lib = import (release.nixpkgs + "/nixos/lib") {
        inherit (pkgs) lib;
      };
    in {
      name = "${testName}-${builtins.replaceStrings ["."] ["_"] release.name}";
      value = nixos-lib.runTest {
        hostPkgs = pkgs;
        imports = [ ./tests/${testName}.nix ];
        _module.args = { inherit blobs; };
        extraBaseModules.imports = [ ./default.nix ];
      };
    };

    # Generate an attribute set such as
    # {
    #   external-unstable = <derivation>;
    #   external-21_05 = <derivation>;
    #   ...
    # }
    allTests = lib.listToAttrs (
      lib.flatten (map (t: map (r: genTest t r) releases) testNames));

    mailserverModule = import ./.;

    # Generate a MarkDown file describing the options of the NixOS mailserver module
    optionsDoc = let
      eval = lib.evalModules {
        modules = [
          mailserverModule
          {
            _module.check = false;
            mailserver = {
              fqdn = "mx.example.com";
              domains = [
                "example.com"
              ];
              dmarcReporting = {
                organizationName = "Example Corp";
                domain = "example.com";
              };
            };
          }
        ];
      };
      options = builtins.toFile "options.json" (builtins.toJSON
        (lib.filter (opt: opt.visible && !opt.internal && lib.head opt.loc == "mailserver")
          (lib.optionAttrSetToDocList eval.options)));
    in pkgs.runCommand "options.md" { buildInputs = [pkgs.python3Minimal]; } ''
      echo "Generating options.md from ${options}"
      python ${./scripts/generate-options.py} ${options} > $out
      echo $out
    '';

    documentation = pkgs.stdenv.mkDerivation {
      name = "documentation";
      src = lib.sourceByRegex ./docs ["logo\\.png" "conf\\.py" "Makefile" ".*\\.rst"];
      buildInputs = [(
        pkgs.python3.withPackages (p: with p; [
          sphinx
          sphinx_rtd_theme
          myst-parser
          linkify-it-py
        ])
      )];
      buildPhase = ''
        cp ${optionsDoc} options.md
        # Workaround for https://github.com/sphinx-doc/sphinx/issues/3451
        unset SOURCE_DATE_EPOCH
        make html
      '';
      installPhase = ''
        cp -Tr _build/html $out
      '';
    };

  in {
    nixosModules = rec {
      mailserver = mailserverModule;
      default = mailserver;
    };
    nixosModule = self.nixosModules.default; # compatibility
    hydraJobs.${system} = allTests // {
      inherit documentation;
      inherit (self.checks.${system}) pre-commit;
    };
    checks.${system} = allTests // {
      pre-commit = git-hooks.lib.${system}.run {
        src = ./.;
        hooks = {
          # docs
          markdownlint = {
            enable = true;
            settings.configuration = {
              # Max line length, doesn't seem to correclty account for lines containing links
              # https://github.com/DavidAnson/markdownlint/blob/main/doc/md013.md
              MD013 = false;
            };
          };
          rstcheck = {
            enable = true;
            entry = lib.getExe pkgs.rstcheckWithSphinx;
            files = "\\.rst$";
          };

          # nix
          deadnix.enable = true;

          # python
          pyright.enable = true;
          ruff = {
            enable = true;
            args = [
              "--extend-select"
              "I"
            ];
          };
          ruff-format.enable = true;

          # scripts
          shellcheck.enable = true;

          # sieve
          check-sieve = {
            enable = true;
            entry = lib.getExe pkgs.check-sieve;
            files = "\\.sieve$";
          };
        };
      };
    };
    packages.${system} = {
      inherit optionsDoc documentation;
    };
    devShells.${system}.default = pkgs.mkShellNoCC {
      inputsFrom = [ documentation ];
      packages = with pkgs; [
        glab
      ] ++ self.checks.${system}.pre-commit.enabledPackages;
      shellHook = self.checks.${system}.pre-commit.shellHook;
    };
    devShell.${system} = self.devShells.${system}.default; # compatibility
  };
}