I am working with the ansible-elasticsearch Ansible playbook from https://github.com/elastic/ansible-elasticsearch. I'm relatively new to Ansible and very new to this playbook. I can get the playbook to start but it quickly fails due to an undefined variable. The GitHub site referenced above lists some of the variables used in the playbook, but not all of them, and of course the undefined variable I've encountered is one of those not listed. Is there, somewhere, a complete list of the variables used in this playbook? It'd be super if the list included some idea of what the values of the variables might be for different use cases, but that might be asking too much. My use case, for example, is in a standalone network, so when (as an example of what I'm running into) es_repo_base is defined as "https://artifacts.elastic.co" that's not going to work, and I'm looking for guidance as to what would be an appropriate substitution for that URL.