system-manager/flake.nix

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    devshell = {
      url = "github:numtide/devshell";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-utils.follows = "flake-utils";
      };
    };
    pre-commit-hooks = {
      url = "github:cachix/pre-commit-hooks.nix";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-utils.follows = "flake-utils";
      };
    };
    rust-overlay = {
      url = "github:oxalica/rust-overlay";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-utils.follows = "flake-utils";
      };
    };
    crane = {
      url = "github:ipetkov/crane";
      inputs = {
        nixpkgs.follows = "nixpkgs";
        flake-utils.follows = "flake-utils";
        rust-overlay.follows = "rust-overlay";
        flake-compat.follows = "pre-commit-hooks/flake-compat";
      };
    };
    treefmt-nix = {
      url = "github:numtide/treefmt-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    { self
    , nixpkgs
    , flake-utils
    , rust-overlay
    , crane
    , devshell
    , treefmt-nix
    , pre-commit-hooks
    ,
    }:
    (flake-utils.lib.eachDefaultSystem (system:
    let
      pkgs = import nixpkgs {
        inherit system;
        overlays = [ (import rust-overlay) devshell.overlays.default ];
      };
      # TODO Pin the version for release
      rust = pkgs.rust-bin.stable.latest;
      llvm = pkgs.llvmPackages_latest;

      craneLib = (crane.mkLib pkgs).overrideToolchain rust.default;

      # Common derivation arguments used for all builds
      commonArgs = {
        src = craneLib.cleanCargoSource ./.;
        buildInputs = with pkgs; [
          dbus
        ];
        nativeBuildInputs = with pkgs; [
          pkg-config
        ];
      };

      # Build only the cargo dependencies
      cargoArtifacts = craneLib.buildDepsOnly (commonArgs // {
        pname = "system-manager";
      });

      system-manager = craneLib.buildPackage (commonArgs // {
        pname = "system-manager";
        inherit cargoArtifacts;
      });

      system-manager-clippy = craneLib.cargoClippy (commonArgs // {
        inherit cargoArtifacts;
        cargoClippyExtraArgs = "--all-targets -- --deny warnings";
      });

      # treefmt-nix configuration
      treefmt.config = {
        projectRootFile = "flake.nix";
        programs = {
          nixpkgs-fmt.enable = true;
          rustfmt = {
            enable = true;
            package = rust.rustfmt;
          };
        };
      };
    in
    {
      packages = {
        inherit system-manager;
        default = self.packages.${system}.system-manager;
      };

      devShells.default = pkgs.devshell.mkShell {
        packages = with pkgs; [
          llvm.clang
          openssl
          pkg-config
          (rust.default.override {
            extensions = [ "rust-src" ];
          })
          (treefmt-nix.lib.mkWrapper pkgs treefmt.config)
        ];
        env = [
          {
            name = "PKG_CONFIG_PATH";
            value = pkgs.lib.makeSearchPath "lib/pkgconfig" [
              pkgs.dbus.dev
              pkgs.systemdMinimal.dev
            ];
          }
          {
            name = "LIBCLANG_PATH";
            value = "${llvm.libclang}/lib";
          }
          {
            # for rust-analyzer
            name = "RUST_SRC_PATH";
            value = "${rust.rust-src}";
          }
          {
            name = "RUST_BACKTRACE";
            value = "1";
          }
          {
            name = "RUSTFLAGS";
            value =
              let
                getLib = pkg: "${pkgs.lib.getLib pkg}/lib";
              in
              pkgs.lib.concatStringsSep " " [
                "-L${getLib pkgs.systemdMinimal} -lsystemd"
              ];
          }
          {
            name = "DEVSHELL_NO_MOTD";
            value = "1";
          }
        ];
        devshell.startup.pre-commit.text = (pre-commit-hooks.lib.${system}.run {
          src = ./.;
          hooks = {
            check-format = {
              enable = true;
              entry = "treefmt --fail-on-change";
            };
            cargo-clippy = {
              enable = true;
              description = "Lint Rust code.";
              entry = "cargo-clippy --workspace -- -D warnings";
              files = "\\.rs$";
              pass_filenames = false;
            };
          };
        }).shellHook;
      };

      checks = {
        inherit
          # Build the crate as part of `nix flake check` for convenience
          system-manager
          system-manager-clippy;
      };
    }))
    //
    {
      lib = import ./nix/lib.nix {
        inherit nixpkgs self;
      };

      systemConfigs.default = self.lib.makeSystemConfig {
        system = flake-utils.lib.system.x86_64-linux;
        modules = [
          ./nix/modules
        ];
      };
    };
}