Deploy a new Europe-specific website on GKE using the same external IP as the existing site but a different domain name. What change do you make to the Ingress configuration?

The most efficient way to use the same external IP for a new domain on an existing GKE Ingress is to modify the existing Ingress resource. GKE Ingress controllers support host-based routing, allowing multiple domains to share a single external IP address. By adding a new host rule to the existing Ingress, you direct traffic for the new domain to the appropriate backend service. Defining a new Ingress resource would typically provision a new external IP address unless explicitly configured otherwise, which isn't the goal here. Creating a new Service of type LoadBalancer would also provision a new IP address and is not the standard way to manage host-based routing with Ingress. While generating a new Ingress resource and specifying the existing IP via annotation is technically possible, modifying the existing Ingress is simpler and more aligned with managing multiple hostnames on a single Ingress.