Book Image

The Kubernetes Book

By : Nigel Poulton, Pushkar Joglekar
Book Image

The Kubernetes Book

By: Nigel Poulton, Pushkar Joglekar

Overview of this book

Kubernetes is the leading orchestrator of cloud-native apps. With knowledge of how to work with Kubernetes, you can easily deploy and manage applications on the cloud or in your on-premises data center. The book begins by introducing you to Kubernetes and showing you how to install it. You’ll learn how to use Kubernetes Services and bring stable and reliable networking to apps that are deployed on Kubernetes. You'll delve deep into the powerful storage subsystem of Kubernetes and learn how to leverage the variety of external storage backends in your applications. As the book progresses, it shows you how to use features such as DaemonSets, Helm, and RBAC to enhance your Kubernetes applications. You'll explore the six categories of identifying vulnerabilities and look at a few ways to prevent and mitigate them. You'll also look at ways to secure the software delivery pipeline by discussing some image-related best practices. The book ends by sharing with you some resources that’ll help take your Kubernetes knowledge to the next level. By the end of the book, you’ll have the confidence and skills to leverage all the features of Kubernetes to develop scalable applications.
Table of Contents (23 chapters)
Free Chapter
1
Chapter 1
3
Chapter 2
5
Chapter 3
7
Chapter 4
9
Chapter 5
11
Chapter 6
13
Chapter 7
15
Chapter 8
17
Chapter 9
19
Chapter 10
21
Chapter 11

Pod Theory

The atomic unit of scheduling in the virtualization world is the Virtual Machine (VM). This means deploying applications in the virtualization world requires scheduling them on VMs.

In the Docker world, the atomic unit is the container. This means deploying applications on Docker that is deploying them inside of containers.

In the Kubernetes world, the atomic unit is the Pod. Ergo, deploying applications on Kubernetes means stamping them out in Pods.

This is fundamental to understanding Kubernetes, so be sure to tag it in your brain as important: virtualization does VMs, Docker does containers, and Kubernetes does Pods:

Figure 4.1: Atomic units of scheduling
Figure 4.1: Atomic units of scheduling

As Pods are the fundamental unit of deployment in Kubernetes, it's vital we understand how they work.

Note

We're going to talk a lot about Pods in this chapter. However, it's important to remember that Pods are just a vehicle for deploying applications.

...