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

Running your Operator

In Chapter 6, Building and Deploying Your Operator, we demonstrated ways to build and run an Operator manually by either compiling locally or building a Docker image to run in a Kubernetes cluster. But, neither of these methods is directly compatible with the OLM, so in order to provide an Operator that can be installed by the OLM, the Operator must be prepared with a bundle that contains metadata about the Operator in a format that the OLM understands. Then, this bundle can be passed to the OLM, which will handle the rest of the installation and life cycle management of the Operator.

Generating an Operator's bundle

An Operator's bundle consists of various manifests that describe the Operator and provide additional metadata, such as its dependencies and APIs. Once created, these manifests can be compiled into a bundle image, which is a deployable container image that is used by the OLM to install the Operator in a cluster.

The simplest way to...