What configuration should be applied to expose an application publicly within a GKE cluster?

To expose an application publicly within a Google Kubernetes Engine (GKE) cluster, configuring a GKE Ingress resource is a suitable approach. Ingress acts as an entry point for external HTTP(S) traffic to reach your applications running in Kubernetes. It allows you to define rules for routing traffic to various services based on the request path or host, leading to more streamlined traffic management and potentially improved performance.

Ingress resources also enable you to consolidate multiple services under a single IP address, utilize SSL/TLS termination, and manage load balancing at the application layer, which is especially useful when deploying microservices. By using Ingress, developers gain the ability to set up more complex routing strategies and integrate seamlessly with Google Cloud's load balancing features.

While a Service resource is fundamental for exposing applications within the GKE cluster and can be configured to expose services to an external audience, using just a Service by itself (even with the LoadBalancer type) doesn't provide the sophisticated routing capabilities of an Ingress. Therefore, utilizing an Ingress resource is a more advanced and suitable configuration for publicly exposing applications, especially in scenarios where traffic routing rules are needed.