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

A real-world use case

Prometheus (https://github.com/prometheus/prometheus) is a tool that is used for monitoring applications and clusters by collecting metrics exported by those applications and storing them in a time series manner. In Chapter 5, Developing an Operator – Advanced Functionality, we implemented basic Prometheus metrics in the nginx Operator to expose aggregate information about the total reconciliation attempts made by the Operator. This was just one small example of the potential application architecture designs that rely on Prometheus for monitoring.

Prometheus overview

Along with scraping and aggregating metrics, Prometheus also defines a data model for creating different types of metrics and implementing them in applications. This model is instrumented via the clients provided by Prometheus in various languages, including Ruby, Python, Java, and Go. These clients make it easy for application developers to export metrics in a format that is compatible...