When you call add_server(name, host, options) without specifying a template server or attributes, the attributes collection is left un-initialized and the render call fails with a nil-dereference.
Change add_server() to default to empty attributes array.
When you call add_server(name, host, options) without specifying a template server or attributes, the attributes collection is left un-initialized and the render call fails with a nil-dereference.
Change add_server() to default to empty attributes array.