Testing with Kubernetes ConfigMaps, secrets, and ingress resource

With the preceding changes described, we are ready to test the system landscape with the Spring Cloud Config Server and the Spring Cloud Gateway replaced by Kubernetes config maps, secrets, and an ingress resource.  As before, when we used the Spring Cloud Gateway as the edge server, the external API will be protected by HTTPS. With this deployment, we will configure the ingress resource to reuse the self-signed certificate we used with the Spring Cloud Gateway for HTTPS. This is illustrated by the following diagram: 

In the next section, we will enhance the certificate usage and replace the self-signed certificate with certificates issued by Let's Encrypt.

The ingress will be exposed on the default HTTPS port, 443, on the Minikube instance. This is handled by the ingress...