Put every variables in top of the file for easy copy to another config

Former-commit-id: 0bd55fdc10

nixos/auto-upgrade.nix

@@ -1,8 +1,10 @@
-{ config, ... }: {
+{ config, ... }:
+let configDir = config.var.configDirectory;
+in {
   system.autoUpgrade = {
     enable = config.var.autoUpgrade;
     dates = "04:00";
-    flake = "${config.var.configDirectory}";
+    flake = "${configDir}";
     flags = [ "--update-input" "nixpkgs" "--commit-lock-file" ];
     allowReboot = false;
   };

nixos/nix.nix

@@ -1,4 +1,6 @@
-{ config, ... }: {
+{ config, ... }:
+let autoGarbageCollector = config.var.autoGarbageCollector;
+in {
   nixpkgs.config = {
     allowUnfree = true;
     allowBroken = true;
@@ -16,7 +18,7 @@
       ];
     };
     gc = {
-      automatic = config.var.autoGarbageCollector;
+      automatic = autoGarbageCollector;
       persistent = true;
       dates = "weekly";
       options = "--delete-older-than 7d";

nixos/users.nix

@@ -1,10 +1,12 @@
-{ config, pkgs, ... }: {
+{ config, pkgs, ... }:
+let username = config.var.username;
+in {
   programs.zsh.enable = true;
   users = {
     defaultUserShell = pkgs.zsh;
-    users.${config.var.username} = {
+    users.${username} = {
       isNormalUser = true;
-      description = "${config.var.username} account";
+      description = "${username} account";
       extraGroups = [ "networkmanager" "wheel" ];
     };
   };

nixos/utils.nix

@@ -1,16 +1,20 @@
-{ pkgs, config, ... }: {
+{ pkgs, config, ... }:
+let
+  hostname = config.var.hostname;
+  keyboardLayout = config.var.keyboardLayout;
+in {
 
-  networking.hostName = config.var.hostname;
+  networking.hostName = hostname;
 
   services = {
     xserver = {
       enable = true;
-      xkb.layout = config.var.keyboardLayout;
+      xkb.layout = keyboardLayout;
       xkb.variant = "";
     };
     gnome.gnome-keyring.enable = true;
   };
-  console.keyMap = config.var.keyboardLayout;
+  console.keyMap = keyboardLayout;
 
   environment.variables = {
     XDG_DATA_HOME = "$HOME/.local/share";