feat: add localisation module

hosts/matej-nixos/configuration.nix

@@ -25,6 +25,7 @@ in
     inputs.self.nixosModules.workstation
     inputs.self.nixosModules.nvidia
     inputs.self.nixosModules.initrd-ssh
+    inputs.self.nixosModules.localisation
   ];
 
   yubikey.enable = true;
@@ -67,9 +68,11 @@ in
   boot.loader.systemd-boot.enable = true;
   boot.loader.efi.canTouchEfiVariables = true;
 
-  time.timeZone = "Europe/Ljubljana";
-  environment.variables.TZ = "America/New_York";
-  i18n.defaultLocale = "en_US.UTF-8";
+  localisation = {
+    enable = true;
+    timeZone = "Europe/Ljubljana";
+    defaultLocale = "en_US.UTF-8";
+  };
 
   # WARN:(@janezicmatej) nix-ld for running pip-installed binaries outside nix, probably want to drop this
   programs.nix-ld.enable = true;

hosts/matej-tower/configuration.nix

@@ -23,6 +23,7 @@
     inputs.self.nixosModules.tuigreet
     inputs.self.nixosModules.workstation
     inputs.self.nixosModules.initrd-ssh
+    inputs.self.nixosModules.localisation
   ];
 
   yubikey.enable = true;
@@ -59,8 +60,11 @@
     pkiBundle = "/var/lib/sbctl";
   };
 
-  time.timeZone = "Europe/Ljubljana";
-  environment.variables.TZ = "Europe/Ljubljana";
+  localisation = {
+    enable = true;
+    timeZone = "Europe/Ljubljana";
+    defaultLocale = "en_US.UTF-8";
+  };
 
   services.udisks2.enable = true;
 

modules/nixos/localisation.nix

@@ -0,0 +1,28 @@
+{
+  lib,
+  config,
+  ...
+}:
+{
+  options = {
+    localisation = {
+      enable = lib.mkEnableOption "localisation defaults";
+
+      timeZone = lib.mkOption {
+        type = lib.types.str;
+      };
+
+      defaultLocale = lib.mkOption {
+        type = lib.types.str;
+      };
+    };
+  };
+
+  config = lib.mkIf config.localisation.enable {
+    time.timeZone = config.localisation.timeZone;
+    i18n.defaultLocale = config.localisation.defaultLocale;
+
+    # NOTE:(@janezicmatej) some apps (e.g. java) need TZ env var explicitly
+    environment.variables.TZ = config.localisation.timeZone;
+  };
+}