Configure `proxy_set_header Host` in kind: Ingress

[shaun-nx]

Overview

As an application developer who manages Ingress routes
I want to explicitly set the value of the upstream host header in Kind: Ingress and VirtualServer
So that I can ensure the same host value is always maintained

This functionality is similar to nginx.ingress.kubernetes.io/upstream-vhost

Requirements

• Users must be able to explicitly configure the upstream Host header value.
• The feature must support standard Kubernetes Ingress resources.
• The feature must support VirtualServer resources.
• When the feature is configured, NGINX Ingress Controller must generate configuration equivalent to: proxy_set_header Host example.internal;
• When the feature is not configured, existing behavior must remain unchanged.
• The feature must not require users to use custom snippets or modify the NGINX template.
• The controller should validate the configured value and reject clearly invalid host values.

Acceptance Criteria

• Allow proxy_set_header Host to be set to an explicit value, other than $host [decision is to implement new annotation upstream-vhost]
• Given an Ingress resource with an explicit upstream host value configured,
  when a request is proxied to the upstream service,
  then the upstream service receives the configured value in the Host header instead of the original request host.
• Given a VirtualServer resource with an explicit upstream host value configured,
  when a request is proxied to the upstream service,
  then the upstream service receives the configured value in the Host header instead of the original request host.
• Given no explicit upstream host value is configured,
  when a request is proxied to the upstream service,
  then the controller preserves the existing default behavior.

[github-actions]

Hi @shaun-nx thanks for reporting!

Be sure to check out the docs and the Contributing Guidelines while you wait for a human to take a look at this 🙂

I've parsed the text of your issue and it looks like you might be mixing up the two Ingress Controllers, please take a look at this page to see the differences between nginx/kubernetes-ingress (this repo) and kubernetes/ingress-nginx.

Cheers!