create optional ingress for Kube API Server

[reshnm]

How to categorize this issue?

/area usability
/kind enhancement
/priority 4

What would you like to be added:

Provide a configuration option that switches from the current Kube API service type Load Balancer to service type Cluster IP + Ingress.

Why is this needed:

For the landscaper service use case a virtual garden installation is created for each tenant. Having a Load Balancer service for each Kube API server would be too expensive. Having an ingress configured for the Kube API server would also be more user friendly as the ingress URL could be moved to a different installation.

[vpnachev]

Have you evaluated https://github.com/gardener/gardener/blob/master/docs/proposals/08-shoot-apiserver-via-sni.md?
It is exposing all kube-apiserver services created in a seed cluster via single LB service.

[achimweigel]

@vpnachev very interesting proposal. Unfortunately, I'm not a network export and I'm not sure what is the main advantage of this approach compared to deploy an ingress controller and an ingress resource for every kube api server?

[achimweigel]

@danielfoehrKn I reopened the issue because we still use the virtual garden for our landscaper as a service. In that use case we have one instance of the virtual garden per landscaper instance. Therefore we need some solution here.