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

Chapter 4: Developing an Operator with the Operator SDK

With a completed design outline for an Operator, it is now possible to begin the actual work of developing it. This means writing and compiling code that can be deployed onto an actual running Kubernetes cluster. For this chapter, the Operator SDK will be used to initialize the scaffolding of a boilerplate Operator project. From there, the technical steps to develop the rest of a basic Operator will be demonstrated as a tutorial. This guide will follow the Operator design already planned in Chapter 3, Designing an Operator – CRD, API, and Target Reconciliation, which focused on developing a Level II Operator to deploy and upgrade a simple Nginx Pod.

As a tutorial, this chapter will follow the process for building an Operator from scratch with Go. Beginning with the initialization of boilerplate project code, the guide will then follow through the steps of defining the Operator API and generating the corresponding CustomResourceDefinition...