Generate Units::Defaults controller

bin/rails g controller Units/Defaults index

app/controllers/units/defaults_controller.rb

@@ -0,0 +1,8 @@
+class Units::DefaultsController < ApplicationController
+  before_action except: :index do
+    raise AccessForbidden unless current_user.at_least(:admin)
+  end
+
+  def index
+  end
+end