The Need for Container Orchestration

The k8s-for-beginners container we built in Exercise 1.01, Creating a Docker Image and Uploading it to Docker Hub, is nothing but a simple demonstration. In the case of a serious workload deployed in a production environment, and to enable hundreds of thousands of containers running in a cluster, we have many more things to consider. We need a system to manage the following problems:

Container Interactions

As an example, suppose that we are going to build a web app with a frontend container displaying information and accepting user requests, and a backend container serving as a datastore that interacts with the frontend container. The first challenge is to figure out how to specify the address of the backend container to the frontend container. It is not a good idea to hardcode the IP, as the container IP is not static. In a distributed system, it is not uncommon for containers or machines to fail due to unexpected issues. So, the link between...