They send traffic to the Service that exposes your Pods, so yes, it only gets routed to Endpoints that work according to readiness tests.
I was looking into this because if I have a pod with 3 containers, if 1 container wasn't running, nginx-ingress stopped serving traffic. I actually want to continue serving traffic if a certain container is still running, not all 3 running necessarily
Do you know or have any documentation on how nginx-ingress actually does its readiness/liveness checks?
If any of the containers in a Pod aren't ready, the endpoints controller[2] removes the Endpoint object corresponding to that Pod. ingress-nginx watches these Endpoints objects[3] to determine which Pods it should send traffic to.
Edit: As to your use case, I think you should remove the readiness probe from that one container you don't care about.
[1]: https://kubernetes.io/docs/tasks/configure-pod-container/con...
[2]: https://kubernetes.io/docs/concepts/overview/components/#kub...
[3]: https://kubernetes.github.io/ingress-nginx/user-guide/miscel...
https://kubernetes.io/docs/tasks/configure-pod-container/con...