Kubernetes is a powerful tool. It can help you manage complex applications and provide you with the ability to easily automate tasks involved in managing them. In this course, we will start exploring Kubernetes from a beginner's standpoint. We will discuss what Kubernetes is and what it does, and we will work with some of the basic functionality of Kubernetes hands-on. We will build a simple Kubernetes cluster. We will also deploy a sample microservice application to the cluster in order to explore how Kubernetes can help easily manage such applications.

A Practical Guide to Kubernetes

# Switching from John to Us

John is frustrated. He can access the cluster, but he is not permitted to perform any operation. He cannot even list the Pods. Naturally, he asked us to be more generous and allow him to "play" with our cluster.

Since we are not taking anything for granted, we decided that the first action should be to verify John's claim. Is it true that he cannot even retrieve the Pods running inside the cluster?

Before we move further, we'll stop impersonating John and go back to using the cluster with god-like administrative privileges granted to the `minikube` user.

kubectl config use-context minikube

kubectl get all

Now that we switched to the `minikube` context (and the `minikube` user), we regained full permissions, and `kubectl get all` returned all the objects from the `default` Namespace.

Let's verify that John indeed cannot list Pods in the `default` Namespace.

We could configure the same certificates as those he's using, but that would complicate the process. Instead, we'll use a `kubectl` command that will allow us to check whether we could perform an action if we would be a specific user.

In this lesson, we will look into all the pre-defined cluster roles.