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

The Kubernetes Persistent Volume Subsystem

From a day-to-day perspective, this is where you'll spend most of your time configuring and interacting with Kubernetes storage.

You start out with raw storage on the left of Figure 7.3. This plugs in to Kubernetes via a CSI plugin. You then use the resources provided by the persistent volume subsystem to leverage the storage in your apps:

Figure 7.3: High-level architecture

The three main resources in the persistent volume subsystem are:

  • Persistent Volumes (PV)
  • Persistent Volume Claims (PVC)
  • Storage Classes (SC)

At a high level, PVs are how we represent storage in Kubernetes. PVCs are like tickets that let a Pod use a PV. SCs make it all dynamic.

Let's walk through a quick example.

Assume that you have a Kubernetes cluster and an external storage system. The storage vendor provides a CSI plugin so that you can leverage its storage assets inside of your Kubernetes cluster....