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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Chapter 8: Using Helm with the Operator Framework

Here are some answers to the questions presented in this chapter:

  1. An operator works by leveraging a custom controller and custom resources. When a new custom resource is created, the operator will perform the logic implemented by the custom controller. Changes to the custom resource also trigger the controller logic. Operators are typically implemented to install and manage the life cycle of an application.
  2. When using the Helm CLI, you must execute the install, upgrade, rollback, and uninstall commands from the command line. However, when using a Helm-based operator, these commands are performed automatically when you create, modify, or delete a custom resource. When using a Helm-based operator, you don’t have to run any Helm CLI commands locally.

    With regard to the application life cycle, the Helm CLI allows users to roll back to a previous revision, while the Helm operator does not allow this because it does not...