Yes, that does appear to be something of a chicken-and-egg problem… what the discourse-setup script does, more-or-less, is just copy samples/standalone.yml to containers/app.yml and edit a bunch of stuff in response to your answers to a bunch of questions. You can do the same thing yourself – copy the file, edit to suit. It’s how all installs used to be done before @codinghorror decided he wanted to show he could write bash scripts with the best of 'em. 