Book Image

The Kubernetes Operator Framework Book

By : Michael Dame
1 (1)
Book Image

The Kubernetes Operator Framework Book

1 (1)
By: Michael Dame

Overview of this book

From incomplete collections of knowledge and varying design approaches to technical knowledge barriers, Kubernetes users face various challenges when developing their own operators. Knowing how to write, deploy, and pack operators makes cluster management automation much easier – and that's what this book is here to teach you. Beginning with operators and Operator Framework fundamentals, the book delves into how the different components of Operator Framework (such as the Operator SDK, Operator Lifecycle Manager, and OperatorHub.io) are used to build operators. You’ll learn how to write a basic operator, interact with a Kubernetes cluster in code, and distribute that operator to users. As you advance, you’ll be able to develop a sample operator in the Go programming language using Operator SDK tools before running it locally with Operator Lifecycle Manager, and also learn how to package an operator bundle for distribution. The book covers best practices as well as sample applications and case studies based on real-world operators to help you implement the concepts you’ve learned. By the end of this Kubernetes book, you’ll be able to build and add application-specific operational logic to a Kubernetes cluster, making it easier to automate complex applications and augment the platform.
Table of Contents (16 chapters)
1
Part 1: Essentials of Operators and the Operator Framework
4
Part 2: Designing and Developing an Operator
9
Part 3: Deploying and Distributing Operators for Public Use

Technical requirements

This chapter will rely on the code from previous chapters to build a container image and deploy that image in a Kubernetes cluster. As such, the technical requirements for this chapter necessitate access to a cluster and container management tool such as Docker. However, it is not explicitly required to use the code from the previous chapters, as the commands and processes explained will work with any operator-sdk project. Therefore, the minimum recommended requirements for this chapter are as follows:

  • An internet connection (to pull Docker base images and push built container images to a public registry).
  • Access to a running Kubernetes cluster. This can be any cluster, although it is recommended to use a tool such as Kubernetes in Docker (kind) (https://kind.sigs.k8s.io/) or minikube (https://minikube.sigs.k8s.io/docs/) so that it is not costly to destroy and recreate clusters if needed.
  • An up-to-date version of kubectl (https://kubernetes.io...