Help: container name as environment variable

I’m unfamiliar with how to use the catalog – all my stuff is orchestrated from the command line with rancher-compose. Adding the catalog was pretty easy, and spinning up a new stack was even easier!

I have some questions, though:

  1. How does it know what domain for which it must request a certificate? https://github.com/fatk/docker-letsencrypt-nginx-proxy-companion-examples has a “simple-site” example which has worked very well for orchestrating my Rancher server itself but I can’t see where to put my own “simple-site” in your example.
  2. Similarly, where do you put the services which will use those certs? Must they be in the same stack so they can share the volumes, or do you have your web/mail/whatever-needs-a-cert containers in a separate stack and then cross-link to this one to access the certs?
  3. Finally, can more than one of these stacks run on a single host?

Thank you in advance for your help. This has been a blocker for me for a long, long time.