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

Setting up your project

The first step in starting a fresh Operator project is to initialize an empty project structure. First, create an empty project directory with mkdir nginx-operator and cd into it. Now, initialize a boilerplate project structure with the following:

operator-sdk init --domain example.com --repo github.com/example/nginx-operator

Note

This command may take a few moments to complete the first time it is run.

This command sets up a lot of different files and folders that will be filled in with the custom APIs and logic for the Operator we are building. The once-empty project directory should now contain the following files:

~/nginx-operator$ ls
total 112K
drwxr-xr-x   12 mdame staff  384 Dec 22 21:07 . 
drwxr-xr-x+ 282 mdame staff 8.9K Dec 22 21:06 .. 
drwx------    8 mdame staff  256 Dec 22 21:07 config
drwx------    3 mdame staff   96 Dec 22 21:06 hack
-rw--...