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

Autoscaling

Chapter 5, Kubernetes Deployments showed us how to manually scale the number of Pod replicas. However, manually scaling a set of Pods does not scale (excuse the pun). As an example, if demand on your application spikes at 4:20 a.m. it's far from ideal if you need to page an operator who will then log on to the cluster and manually increase the number of replicas. The same applies if you need to scale the number of nodes to your cluster.

With these challenges in mind, Kubernetes offers several auto scaling technologies.

The Horizontal Pod Autoscaler (HPA) dynamically increases and decreases the number of Pods in a Deployment based on demand.

The Cluster Autoscaler (CA) dynamically increases and decreases the number of nodes in your cluster based on demand.

The Vertical Pod Autoscaler (VPA) attempts to right size your Pods, but it's currently an alpha product.

Horizontal Pod Autoscaler (HPA)

HPAs are stable resources in the autoscaling/v1 API group...