Hybrid Cloud Apps with OpenShift and Kubernetes

Chapter 2. Getting Started with OpenShift and Kubernetes

In this chapter, we cover a variety of topics that present a foundational understanding of Kubernetes and OpenShift. We begin with an overview of the Kubernetes architecture and then describe several deployment options that will enable you to get both a basic Kubernetes environment and an OpenShift environment up and running. Next, we give an introduction to the command-line tools kubectl and oc, which are used for interacting with Kubernetes and OpenShift respectively. We then introduce a short review of the fundamental Kubernetes concepts of pods, deployments, and service accounts. In the second half of this chapter, we present several enhancement concepts that OpenShift provides over traditional Kubernetes. We then conclude this chapter with a discussion of more advanced topics that are often used when running Kubernetes or OpenShift in production.

Kubernetes Architecture

The Kubernetes architecture at a high level is relatively straightforward. It is composed of a master node and a set of worker nodes. The nodes can be either physical servers or VMs. Users of the Kubernetes environment interact with the master node using either a CLI (kubectl), an API, or a GUI. The master node is responsible for scheduling work across the worker nodes. In Kubernetes, the unit of work that is scheduled is called a pod, and a pod can hold one or more containers. The primary components that exist on the master node are the kube-apiserver ...