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

Creating CRDs

While Helm is often used to create traditional Kubernetes resources, it can also be used to create CRDs and CRs. CRDs are used to define resources that are not native to the Kubernetes API. You may want to use this functionality to augment the abilities that Kubernetes provides. CRs are resources that implement the CRD’s specification. As a result, it’s important to ensure that a CRD is always created before the CRs that implement it.

Helm is able to ensure CRDs are created and registered to Kubernetes before CRs are included in a Helm chart when CRDs are included in the chart’s crds/ folder. All CRDs defined under this folder are created before those in templates/.

An example crds/ folder is shown here:


The my-custom-resource-crd.yaml file may have the following contents:

kind: CustomResourceDefinition
  name: my-custom-resources.learnhelm...