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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Understanding chart definitions

The Chart.yaml file, also known as the chart definition, is a resource that declares different metadata about a Helm chart. This file is required and if it is not included in a chart's file structure, you'll receive the following error:

Error: validation: chart.metadata is required

In Chapter 3, Installing Your First Helm Chart, we explored the chart definition of Bitnami's WordPress chart by running the helm show chart command. Recall this chart definition by running this command again. We will assume that the Bitnami chart repository has already been added since this task was performed in Chapter 3, Installing Your First Helm Chart:

$ helm show chart bitnami/wordpress --version 8.1.0

Below lists the chart definition of the wordpress chart.

Figure 4.1 – The chart definition of the wordpress chart.

The chart definition, or the Chart.yaml file, can contain many different fields. Some of the fields...