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

Pod Life Cycle and Kubernetes Components

The previous sections in this chapter briefly described the Kubernetes components and how they work internally with each other. On the other hand, we also demonstrated how to use some Kubernetes API objects (Pods, Services, and Deployments) to compose your applications.

But how is a Kubernetes API object managed by different Kubernetes components? Let's consider a pod as an example. Its life cycle can be illustrated as follows:

Figure 2.20: The process behind the creation of a pod

This entire process can be broken down as follows:

  1. A user starts to deploy an application by sending a Deployment YAML manifest to the Kubernetes API server. The API server verifies the request and checks whether it's valid. If it is, it persists the Deployment API object to its backend datastore (etcd).

    Note

    For any step that evolves by modifying API objects, interactions have to happen between etcd and the API server, so...