Complete deployment of the sample guestbook application

Having taken a detour to understand the dynamic configuration of applications using a ConfigMap, you will now return to the deployment of the rest of the guestbook application. You will once again come across the concepts of deployment, ReplicaSets, and pods. Apart from this, you will also be introduced to another key concept, called a service.

To start the complete deployment, we are going to create a service to expose the Redis master service.

Exposing the Redis master service

When exposing a port in plain Docker, the exposed port is constrained to the host it is running on. With Kubernetes networking, there is network connectivity between different pods in the cluster. However, pods themselves are ephemeral in nature, meaning they can be shut down, restarted, or even moved to other hosts without maintaining their IP address. If you were to connect to the IP of a pod directly, you might lose connectivity if that...