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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Upgrading the WordPress release

Upgrading a release refers to the process of modifying the values that a release was installed with or upgrading to a newer version of the chart. In this section, we will upgrade the WordPress release by configuring additional values around the WordPress replica and resource requirements.

Modifying the Helm values

It is common for Helm charts to expose values to configure the number of instances of an application and their related set of resources. The following screenshots illustrate several portions of the helm show values command that relate to the values used for this purpose.

The first value, replicaCount, is straightforward to set. Since replica is a Kubernetes term that describes the number of Pods needed to deploy an application, it's implied that replicaCount is used to specify the number of application instances that are deployed as part of a release:

Figure 3.23 – replicaCount in the helm show values command