Book Image

The Kubernetes Workshop

By : Zachary Arnold, Sahil Dua, Wei Huang, Faisal Masood, Mélony Qin, Mohammed Abu Taleb
5 (1)
Book Image

The Kubernetes Workshop

5 (1)
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

StatefulSets

StatefulSets are used to manage stateful replicas. Similar to a Deployment, a StatefulSet creates and manages the specified number of Pod replicas from an identical Pod template. However, where StatefulSets differ from Deployments is that they maintain a unique identity for each of their Pods. So, even if all the Pods are of identical specs, they are not interchangeable. Each of the Pods has a sticky identity that can be used by the application code to manage the state of the application on a particular Pod. For a StatefulSet with n replicas, each Pod is assigned a unique integer ordinal between 0 and n – 1. The names of the Pods reflect the integer identity assigned to them. When a StatefulSet is created, all the Pods are created in the order of their integer ordinal.

Each of the Pods managed by a StatefulSet will persist their sticky identity (integer ordinal) even if the Pod restarts. For example, if a particular Pod crashes or is deleted, a new Pod will be...