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 templates

The primary purpose of a Helm chart is to create and manage the Kubernetes resources that make up an application. This is accomplished through chart templates, with values serving as parameters to customize those templates. In this section, we will discuss how Helm templates and values function.

Helm charts must contain a templates/ directory that defines the Kubernetes resources to be deployed (although this directory is not strictly required if the chart declares dependencies). The contents under the templates/ directory are YAML files that are made up of Kubernetes resources. The contents of a templates/ directory may appear similar to the following:


The configmap.yaml resource may then look as follows:

apiVersion: v1
kind: ConfigMap
  name: {{ .Release.Name }}
  configuration.txt: |-
    {{ ...