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
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.