Book Image

Learn Helm

By : Andrew Block, Austin Dewey
Book Image

Learn Helm

By: Andrew Block, Austin Dewey

Overview of this book

Containerization is currently known to be one of the best ways to implement DevOps. While Docker introduced containers and changed the DevOps era, Google developed an extensive container orchestration system, Kubernetes, which is now considered the frontrunner in container orchestration. With the help of this book, you’ll explore the efficiency of managing applications running on Kubernetes using Helm. Starting with a short introduction to Helm and how it can benefit the entire container environment, you’ll then delve into the architectural aspects, in addition to learning about Helm charts and its use cases. You’ll understand how to write Helm charts in order to automate application deployment on Kubernetes. Focused on providing enterprise-ready patterns relating to Helm and automation, the book covers best practices for application development, delivery, and lifecycle management with Helm. By the end of this Kubernetes book, you will have learned how to leverage Helm to develop an enterprise pattern for application delivery.
Table of Contents (15 chapters)
Section 1: Introduction and Setup
Section 2: Helm Chart Development
Section 3: Adanced Deployment Patterns
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Verifying Helm templating

In the previous chapter, we built a Helm chart from scratch. The final product was quite complex, containing parameterization, conditional templating, and life cycle hooks. Since one of the primary purposes of Helm is to create Kubernetes resources, you should ensure that your resource templates are generated properly before they are applied to a Kubernetes cluster. This can be done in a variety of ways, which we will discuss in the following section.

Validating template generation locally with helm template

The first way to validate your chart's templating is to use the helm template command, which can be used to render a chart template locally and display its fully rendered contents in the standard output.

The helm template command has the following syntax:

$ helm template [NAME] [CHART] [flags]

This command renders a template locally, using the NAME argument to satisfy the .Release built-in object and the CHART argument for the chart...