Try to fix proxy-protocol and http01 challenge

[splattner]

When the proxy-protocol is enabled, http01 challenges are not working.
Cert-manager tries to validate the http01 challenge and for some reason, kubernetes redirects the correctly made call to the external ip adress of the loadbalancer, directly to the nginx ingress controller pod. As the external LoadBalancer does use the proxy-protocol and nginx ingress controller has use-proxy-protocol enabled, the call from cert-manager fails.

See cert-manager/cert-manager#466 & kubernetes/kubernetes#66607

and see also https://github.com/compumike/hairpin-proxy

[splattner]

"fixed" with the hairpin-proxy solution.

ArgoCD App: https://github.com/acend/infrastructure/blob/main/deploy/bootstrap/hairpin-proxy.yaml
hairpin: https://github.com/acend/infrastructure/tree/main/deploy/hairpin-proxy/base
Doc: https://github.com/acend/infrastructure/blob/main/docs/applications.md#hairpin-proxy