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)
Preface

Working with Stateful Applications

The previous exercise demonstrates the challenge of working with stateful applications in a distributed context. As a brief overview, a stateless app is an application program that does not save client data generated in one session for use in the next session with that client. This means that in general, a stateless application depends entirely on the input to derive its output. Imagine a server displaying a static web page that does not need to change for any reason. In the real world, stateless applications typically need to be combined with stateful applications in order to create a useful experience for clients or consumers of the application. There are, of course, exceptions to this.

A stateful application is one whose output depends on multiple factors, such as user input, input from other applications, and past saved events. These factors are called the "state" of the application, which determines its behavior. One of the most...