Hey Chuck,
So I have been working with our IT team a bit and have a general understanding of this. NGinx would need to be installed on the cluster that your app docker container is running on. We install it using NGinx’s helm repo
https://docs.nginx.com/nginx-ingress-controller/installation/installation-with-helm/ .
What is happening is your app is running on that app container but it is not hosted publicly outside of the cluster itself. That nginx ingress will host a public IP that you can then point at your localhost:8080 allowing the app to show up at that endpoint.
I hope that is a little helpful. I am not 100% familiar with how it is set up but that is my understanding of it.