Book Image

Managing Kubernetes Resources Using Helm - Second Edition

By : Andrew Block, Austin Dewey
Book Image

Managing Kubernetes Resources Using Helm - Second Edition

By: Andrew Block, Austin Dewey

Overview of this book

Containerization is one of the best ways to implement DevOps, and learning how to execute it effectively is an essential part of a developer’s skillset. Kubernetes is the current industry standard for container orchestration. This book will help you discover the efficiency of managing applications running on Kubernetes with Helm. Starting with a brief introduction to Helm and its impact on users working with containers and Kubernetes, you’ll delve into the primitives of Helm charts and their architecture and use cases. From there, you’ll understand how to write Helm charts in order to automate application deployment on Kubernetes and work your way toward more advanced strategies. These enterprise-ready patterns are focused on concepts beyond the basics so that you can use Helm optimally, looking at topics related to automation, application development, delivery, lifecycle management, and security. By the end of this book, you’ll have learned how to leverage Helm to build, deploy, and manage applications on Kubernetes.
Table of Contents (18 chapters)
Part 1: Introduction and Setup
Part 2: Helm Chart Development
Part 3: Advanced Deployment Patterns

Testing in a live cluster

Understanding how to perform tests in a live Kubernetes cluster is an essential part of developing and maintaining a Helm chart. Live testing helps ensure your chart is functioning as intended and can be used to help prevent regressions as new additions are introduced to your chart over time.

Testing can involve, but is not limited to, the following two different constructs:

  • Readiness probes and the helm install --wait command
  • Test hooks and the helm test command

A readiness probe is a type of health check in Kubernetes that, upon success, marks a pod as Ready and makes the pod eligible to receive ingress traffic. An example of a readiness probe is located at chapter9/guestbook/templates/deployment.yaml:

    path: /
    port: http

This readiness probe will mark the pod as Ready when an HTTP GET request succeeds against the / path.

Readiness probes can...