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

Persistent Volumes

The Volumes we have seen so far have the limitation that their life cycle depends on the life cycle of pods. Volumes such as emptyDir or hostPath get deleted when the pod using them is deleted or gets restarted. For example, if we use Volumes to store user data and inventory records for our e-commerce website, the data will be deleted when the application pod restarts. Hence, Volumes are not suited to store data that you want to persist.

To solve this problem, Kubernetes supports persistent storage in the form of a Persistent Volume (PV). A PV is a Kubernetes object that represents a block of storage in the cluster. It can either be provisioned beforehand by the cluster administrators or be dynamically provisioned. A PV can be considered a cluster resource just like a node and, hence, it is not scoped to a single namespace. These Volumes work similarly to the Volumes we have seen in previous sections. The life cycle of a PV doesn't depend on the life cycle...