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

Stability and safety

Applications and components in a Kubernetes cluster can occasionally be prone to unexpected failures, such as network timeouts or code panics due to unforeseen bugs. It is part of an Operator's job to monitor for these spontaneous failures and attempt to recover from them. But of course, human error in the pursuit of adjusting the system can be another source of failure. As a result, any interaction with or modification of the core system components in Kubernetes brings inherent risk. This is elevated because manual adjustments to one component can contain errors (even minor ones) that cause a domino effect, as other components that depend on it begin reacting to the original error.

Perhaps the prime objective of an Operator is to provide stability and safety in production environments. Here, stability refers to the ongoing performant operation of the Operand programs, and safety is the ability of an Operator to sanitize and validate any inputs or modifications...