Book Image

The Kubernetes Workshop

By : Zachary Arnold, Sahil Dua, Wei Huang, Faisal Masood, Mélony Qin, Mohammed Abu Taleb
Book Image

The Kubernetes Workshop

By: Zachary Arnold, Sahil Dua, Wei Huang, Faisal Masood, Mélony Qin, Mohammed Abu Taleb

Overview of this book

Thanks to its extensive support for managing hundreds of containers that run cloud-native applications, Kubernetes is the most popular open source container orchestration platform that makes cluster management easy. This workshop adopts a practical approach to get you acquainted with the Kubernetes environment and its applications. Starting with an introduction to the fundamentals of Kubernetes, you’ll install and set up your Kubernetes environment. You’ll understand how to write YAML files and deploy your first simple web application container using Pod. You’ll then assign human-friendly names to Pods, explore various Kubernetes entities and functions, and discover when to use them. As you work through the chapters, this Kubernetes book will show you how you can make full-scale use of Kubernetes by applying a variety of techniques for designing components and deploying clusters. You’ll also get to grips with security policies for limiting access to certain functions inside the cluster. Toward the end of the book, you’ll get a rundown of Kubernetes advanced features for building your own controller and upgrading to a Kubernetes cluster without downtime. By the end of this workshop, you’ll be able to manage containers and run cloud-based applications efficiently using Kubernetes.
Table of Contents (20 chapters)

How kubectl Communicates with Kubernetes

As we saw in the previous chapter, the API server manages communications between the end-user and Kubernetes, and it also acts as an API gateway to the cluster. To achieve this, it implements the RESTful API over the HTTP and HTTPS protocols to perform CRUD operations to populate and modify Kubernetes API objects such as pods, services, and more based upon the instructions sent by a user via kubectl. These instructions can be in various forms. For example, to retrieve information for pods running in the cluster, we would use the kubectl get pods command, while to create a new pod, we would use the kubectl run command.

First, let's take a look at what happens behind the scenes when you run a kubectl command. Take a look at the following illustration, which provides an overview of the process, and then we will take a closer look at the different details of the process:

Figure 3.1: A representative flowchart for the...