Setting up multiple rail applications using nginx and Puma

I have a web server serving multiple Rails applications using a combination of nginx and Passenger. It's pretty straightforward because Passenger sets up preferences for pretty much everything you need to connect to nginx.

I found a " Rails Application with Puma " which seems to explain how to create nginx and Puma together. How should this configuration be changed to serve a second Rails application on the same server?

Also, this guide doesn't say anything about restarting the app automatically if there is a system restart or some other problem. Is there a way to do this? It seems that the nginx + Passenger combo does this by default.