Book Image

Managing Kubernetes Resources Using Helm - Second Edition

By : Andrew Block, Austin Dewey
Book Image

Managing Kubernetes Resources Using Helm - Second Edition

By: Andrew Block, Austin Dewey

Overview of this book

Containerization is one of the best ways to implement DevOps, and learning how to execute it effectively is an essential part of a developer’s skillset. Kubernetes is the current industry standard for container orchestration. This book will help you discover the efficiency of managing applications running on Kubernetes with Helm. Starting with a brief introduction to Helm and its impact on users working with containers and Kubernetes, you’ll delve into the primitives of Helm charts and their architecture and use cases. From there, you’ll understand how to write Helm charts in order to automate application deployment on Kubernetes and work your way toward more advanced strategies. These enterprise-ready patterns are focused on concepts beyond the basics so that you can use Helm optimally, looking at topics related to automation, application development, delivery, lifecycle management, and security. By the end of this book, you’ll have learned how to leverage Helm to build, deploy, and manage applications on Kubernetes.
Table of Contents (18 chapters)
Part 1: Introduction and Setup
Part 2: Helm Chart Development
Part 3: Advanced Deployment Patterns

Understanding the Guestbook operator control loop

In this chapter, we will write a Helm-based operator that will be used to install the Guestbook Helm chart. This chart can be found in the Packt repository at

The following diagram demonstrates how the Guestbook operator will function once it has been deployed:

Figure 11.1 – The Guestbook operator control loop

The Guestbook operator constantly watches for the creation, deletion, or modification of Guestbook CRs. When a Guestbook CR is created, the operator will install the Guestbook Helm chart, and when the CR is modified, it upgrades the release accordingly so that the state of the cluster matches the desired intent as defined by the CR. Similarly, when the CR is deleted, the operator uninstalls the release.

With an understanding of how the operator’s control loop will...