users: custom property to define users with root

common/users/default.nix

@@ -1,3 +1,9 @@
+{ config, lib, pkgs, ... }:
+
+let
+  inherit (lib) mkIf mkOption types genAttrs;
+  cfg = config.fountain;
+in
 {
   # TODO: consider DRY-ing these
   imports = [
@@ -7,5 +13,21 @@
     ./trungle.nix
   ];
 
-  users.mutableUsers = false;
+  options.fountain = {
+    admins = mkOption {
+      type = types.listOf types.str;
+      default = [ ];
+      description = "List of users who should have root on this system";
+    };
+  };
+
+  config = {
+    users.mutableUsers = false;
+
+    users.users = genAttrs cfg.admins
+      (name: {
+        extraGroups = [ "wheel" ];
+      }
+      );
+  };
 }