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

Understanding the need for advanced functionality

With a basic, functional Operator already built and ready for deployment, you may be asking, What else do I really need? Indeed, now that your operand is installable and its health is managed by your Operator, there may be nothing more to do. This is a perfectly acceptable level of functionality for an Operator to have. In fact, it may be preferable to start with a simple Operator and iterate as your development resources allow (recall discussing this in Chapter 3, Designing an Operator – CRD, API, and Target Reconciliation).

The point is that there is no shame during the development of your Operator in stopping here. The Capability Model defines lower-level Operators for a reason (in other words, if it was unacceptable to have an Operator that can only install an operand, then why would Level I be defined at all?).

However, the Capability Model does define higher-level Operators for a reason too. It is not difficult to...