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)
1
Part 1: Introduction and Setup
5
Part 2: Helm Chart Development
12
Part 3: Advanced Deployment Patterns

Uninstalling the WordPress release

Uninstalling a Helm release means deleting the Kubernetes resources that it manages. In addition, the uninstall command deletes the release’s history. While this is often what we want, specifying the --keep-history flag will instruct Helm to retain the release history.

The syntax for the uninstall command is very simple:

helm uninstall RELEASE_NAME [...] [flags]

Uninstall the WordPress release by running the helm uninstall command:

$ helm uninstall wordpress -n chapter3

Once WordPress is uninstalled, you will see the following message:

release "wordpress" uninstalled

You will also notice that the wordpress release no longer exists in the chapter3 namespace:

$ helm list -n chapter3

The output will be an empty table. You can also confirm that the release is no longer present by attempting to use kubectl to get the WordPress deployments:

$ kubectl get deployments -l app.kubernetes.io/name=wordpress -n chapter3...