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

Planning for changes in your Operator

Over any software project's lifespan, changes will be made to the code base. These include bug fixes, refactors, new features, and old features being removed. This is true for Kubernetes, its subprojects, and projects that are built on the platform, such as Operators.

While it's impossible to predict the future of what your Operator will evolve into one day, there are a few ideas that can help you during the design phase to ease transitions and new developments later. These are as follows:

  • Start small.
  • Iterate effectively.
  • Deprecate gracefully.

These decisions have significant benefits in practice when you're maintaining an Operator. However, these are not definitive or strictly specific to Kubernetes Operators. Consider them as general suggestions for developing any software project. But here, we will be examining them in the context of writing an Operator.

Starting small

When planning the original...