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

Deployment

A Deployment is a Kubernetes object that acts as a wrapper around a ReplicaSet and makes it easier to use. In general, in order to manage replicated services, it's recommended that you use Deployments that, in turn, manage the ReplicaSet and the Pods created by the ReplicaSet.

The major motivation for using a Deployment is that it maintains a history of revisions. Every time a change is made to the ReplicaSet or the underlying Pods, a new revision of the ReplicaSet is recorded by the Deployment. This way, using a Deployment makes it easy to roll back to a previous state or version. Keep in mind that every rollback will also create a new revision for the Deployment. The following diagram provides an overview of the hierarchy of the different objects managing your containerized application:

Figure 7.6: Hierarchy of Deployment, ReplicaSet, Pods, and containers

Deployment Configuration

The configuration of a Deployment is actually very similar...