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

Complying with Kubernetes standards for changes

Kubernetes defines a standard set of policies for deprecation (and other breaking changes) that all core projects must abide by. This policy is available at https://kubernetes.io/docs/reference/using-api/deprecation-policy/. It's not necessary to read and understand the whole policy for the purposes of Operator development, as we will highlight some of the relevant bits here. It primarily defines the standards for deprecating parts of the Kubernetes API, with many of the same (or similar) guidelines being applied to other types of deprecation as well (such as user-facing features that are not directly part of the API). It does this by enumerating a list of explicit rules for deprecating changes, some of which we will cover in this section.

As a third-party component, your Operator is under no obligation to follow the Kubernetes deprecation policy. But, in a practical sense, there are benefits to working within the constraints...