Introduce config.nix, to avoid hardcoding (#125)

Add username, full name and email to it.

README.md

@@ -2,7 +2,9 @@
 
 # nixos-unified-template
 
-A multi-platform Nix configuration template optimized as development environment (includes direnv, neovim with LSP[^neovim] and such), based on [nixos-unified]. See [`./modules`](modules/) to see what's available. We support [home-manager] (see `./modules/home`), [nix-darwin] (see `./modules/darwin`) and [NixOS] (see `./modules/nixos`).
+This repository provides a ready-made Nix configuration to manage either your Home environment or whole NixOS systems. It is optimized specifically for development environment (with direnv, neovim with LSP[^neovim], etc.).
+
+Under the hood, it uses [nixos-unified]. See [`./modules`](modules/) to see what's available. We support [home-manager] (see `./modules/home`), [nix-darwin] (see `./modules/darwin`) and [NixOS] (see `./modules/nixos`).
 
 | Platform    | Supported By                              |
 |-------------|-------------------------------------------|
@@ -86,12 +88,12 @@ Whenever you modify your configuration in `./modules/*/*.nix`, you should re-run
 
 The configuration repo has `flake.nix` file in the current directory and some `./modules/{home,darwin,nixos}/*.nix` files containing the [home-manager], [nix-darwin] and [NixOS] configurations respectively that you can review. It also has a [justfile](https://github.com/casey/just), which provides a set of recipes analogous to Make targets to interact with the nix flake.
 
-You can then execute `nix develop`, to ensure you are in the development shell with [just](https://github.com/casey/just) installed, followed by `just run` (or `nix run`) to activate this configuration in your system.
-
-If you prefer, you can simply execute `nix run`, but using `just` will perform some additional validation and ensure you are able to use the other commands in the [justfile](./justfile).
+Run `nix run` to activate this configuration in your system.
 
 To browse the capabilities of [home-manager] (and to see what else can go in your `./modules/home/*.nix` -- such as shell aliases), consult [home-manager options reference](https://nix-community.github.io/home-manager/options.xhtml). You can also run `man home-configuration.nix` in the terminal.
 
+Global configuration is in `./modules/flake-parts/config.nix`. Here, you can specify your user name, email and such settings.
+
 ## What's included
 
 Here we describe just a handful of tools included in this template. See the [./modules](./modules) directory for more.
@@ -142,4 +144,3 @@ sudo ln -s /nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt /etc/ssl/ce
 ```
 
 See https://github.com/NixOS/nix/issues/2899#issuecomment-1669501326
-

configurations/darwin/example.nix

@@ -5,6 +5,7 @@
 let
   inherit (flake) inputs;
   inherit (inputs) self;
+  inherit (flake.config) me;
 in
 {
   imports = [
@@ -16,19 +17,19 @@ in
 
   # For home-manager to work.
   # https://github.com/nix-community/home-manager/issues/4026#issuecomment-1565487545
-  users.users."runner".home = "/Users/runner";
+  users.users."${me.username}".home = "/Users/${me.username}";
 
   home-manager = {
     # Automatically move old dotfiles out of the way
     #
-    # Note that home-manager is not very smart, if this backup file already exists it 
+    # Note that home-manager is not very smart, if this backup file already exists it
     # will complain "Existing file .. would be clobbered by backing up". To mitigate this,
     # we try to use as unique a backup file extension as possible.
     backupFileExtension = "nixos-unified-template-backup";
 
-    # Enable home-manager for "runner" user
-    users."runner" = {
-      imports = [ (self + /configurations/home/runner.nix) ];
+    # Enable home-manager for our user
+    users."${me.username}" = {
+      imports = [ (self + /configurations/home/${me.username}.nix) ];
     };
   };
 

configurations/home/runner.nix

@@ -2,6 +2,7 @@
 let
   inherit (flake) inputs;
   inherit (inputs) self;
+  inherit (flake.config) me;
 in
 {
   imports = [
@@ -17,7 +18,7 @@ in
     config.nix.package
   ];
 
-  home.username = "runner";
-  home.homeDirectory = lib.mkDefault "/${if pkgs.stdenv.isDarwin then "Users" else "home"}/runner";
+  home.username = me.username;
+  home.homeDirectory = lib.mkDefault "/${if pkgs.stdenv.isDarwin then "Users" else "home"}/${me.username}";
   home.stateVersion = "24.11";
 }

configurations/nixos/example/configuration.nix

@@ -1,4 +1,8 @@
 # NOTE: We expect this file to be supplanted by the original /etc/nixos/configuration.nix
+{ flake, ... }:
+let
+  inherit (flake.config) me;
+in
 {
   # These are normally in hardware-configuration.nix
   boot.loader.grub.device = "nodev";
@@ -9,7 +13,7 @@
 
   # For home-manager to work.
   # https://github.com/nix-community/home-manager/issues/4026#issuecomment-1565487545
-  users.users."runner".isNormalUser = true;
+  users.users."${me.username}".isNormalUser = true;
 
   # Used for backwards compatibility, please read the changelog before changing.
   # $ darwin-rebuild changelog

configurations/nixos/example/default.nix

@@ -5,6 +5,7 @@
 let
   inherit (flake) inputs;
   inherit (inputs) self;
+  inherit (flake.config) me;
 in
 {
   imports = [
@@ -13,8 +14,8 @@ in
     ./configuration.nix
   ];
 
-  # Enable home-manager for "runner" user
-  home-manager.users."runner" = {
-    imports = [ (self + /configurations/home/runner.nix) ];
+  # Enable home-manager for our user
+  home-manager.users."${me.username}" = {
+    imports = [ (self + /configurations/home/${me.username}.nix) ];
   };
 }

modules/darwin/default.nix

@@ -5,13 +5,14 @@
 let
   inherit (flake) inputs;
   inherit (inputs) self;
+  inherit (flake.config) me;
 in
 {
   # Use TouchID for `sudo` authentication
   security.pam.enableSudoTouchIdAuth = true;
 
   # These users can add Nix caches.
-  nix.settings.trusted-users = [ "root" "runner" ];
+  nix.settings.trusted-users = [ "root" me.username ];
 
   # Configure macOS system
   # More examples => https://github.com/ryan4yin/nix-darwin-kickstarter/blob/main/rich-demo/modules/system.nix

modules/flake-parts/config.nix

@@ -0,0 +1,27 @@
+{ lib, ... }:
+{
+  options = {
+    me = lib.mkOption {
+      default = { };
+      type = lib.types.submodule {
+        options = {
+          username = lib.mkOption {
+            type = lib.types.str;
+            default = "runner";
+            description = "Your username as shown by `id -un`";
+          };
+          fullname = lib.mkOption {
+            type = lib.types.str;
+            default = "John Doe";
+            description = "Your full name for use in Git config";
+          };
+          email = lib.mkOption {
+            type = lib.types.str;
+            default = "[email protected]";
+            description = "Your email for use in Git config";
+          };
+        };
+      };
+    };
+  };
+}

modules/home/git.nix

@@ -1,4 +1,7 @@
-{ ... }:
+{ flake, ... }:
+let
+  inherit (flake.config) me;
+in
 {
   home.shellAliases = {
     g = "git";
@@ -9,8 +12,8 @@
   programs = {
     git = {
       enable = true;
-      userName = "John Doe";
-      userEmail = "[email protected]";
+      userName = me.fullname;
+      userEmail = me.email;
       ignores = [ "*~" "*.swp" ];
       aliases = {
         ci = "commit";

modules/home/neovim/nixvim.nix

@@ -79,7 +79,7 @@
     # Open lazygit within nvim. 
     {
       action = "<cmd>LazyGit<CR>";
-      key = "<leader>gg"; 
+      key = "<leader>gg";
     }
   ];
 }

modules/nixos/default.nix

@@ -5,10 +5,11 @@
 let
   inherit (flake) inputs;
   inherit (inputs) self;
+  inherit (flake.config) me;
 in
 {
   # These users can add Nix caches.
-  nix.settings.trusted-users = [ "root" "runner" ];
+  nix.settings.trusted-users = [ "root" me.username ];
 
   services.openssh.enable = true;
 }