Extending Kubernetes : Elevate Kubernetes with Extension Patterns, Operators, and Plugins

Rely on this comprehensive guide to understand the extension patterns and discover the extension plugins for Kubernetes. In this book, state-of-the-art extension patterns and extension points of Kubernetes are covered in depth with real-life use cases and examples. There are comprehensive discussions in the text on all possible aspects of Kubernetes, starting from end-user to the fully-automated controller development. The book focuses on creating applications that work on Kubernetes and also interact and operate Kubernetes itself. The book starts with a recap of Kubernetes, its rich configuration options, extension patterns, and points. The journey of extending Kubernetes starts with the CLI tool plugins. By the end of this section, you will be able to create and manage kubectl plugins. Then, the API access plugins with authentication and authorization webhooks are presented. In this section, you will learn how to extend and interfere with the API flow of Kubernetes. You then move on to learn how to extend Kubernetes API with new resources and controllers. You will make Kubernetes API work for you by creating a Kubernetes operator. Extensions for Kubernetes schedulers are covered to create a custom scheduler and run it side-by-side with the default scheduler. Finally, the last extension points will be discussed for the infrastructure, such as networking or storage. At the end of the text, you will learn the upcoming extension points. This book is designed to cover all the extension points of Kubernetes with state-of-the-art implementations. This book is intended for those who wish to understand Kubernetes in depth and go further by making Kubernetes work for their custom requirements. By the end of this book, readers with a cloud-native mindset will broaden their vision to create future-proof applications. Rather than focus on overwhelming theoretical information and YAML files for Kubernetes resources, readers are provided with the philosophy behind Kubernetes extensions. With real-life examples and hands-on development steps, you will be more confident in working with Kubernetes. What You Will Learn \* Know the Kubernetes extension patterns and available extension points \* Be familiar with the philosophy behind Kubernetes extensions and how they should be integrated into the clusters \* Design Kubernetes extensions and make Kubernetes work for you \* Develop, deploy, and operate plugins for Kubernetes ranging from the CLI tool to custom resources, schedulers, infrastructure, and more \* Study real-life use cases for extending Kubernetes with code examples Who This Book Is For Software engineers, developers, DevOps engineers, cloud security analysts, architects, and managers who have Kubernetes in their short- and long-term plans Table of Contents About the Author About the Technical Reviewer Introduction Chapter 1: Introduction Kubernetes Recap Control Plane Components kube-apiserver etcd kube-scheduler kube-controller-manager cloud-controller-manager Node Components kubelet kube-proxy Configuring the Kubernetes Cluster Kubernetes Extension Patterns Controller Webhook Binary Plugin Kubernetes Extension Points Key Takeaways Chapter 2: kubectl Plugins kubectl Installation and Usage kubectl Plugin Design Create Your First kubectl Plugins Plugin Repository: krew Key Takeaways Chapter 3: API Flow Extensions Kubernetes API Flow Authentication Authorization Admission Control Authentication Webhooks Kubernetes API Server Configuration Webhook Server Authorization Webhooks Kubernetes API Server Configuration Webhook Server Dynamic Admission Controllers Webhook Configuration Resources Webhook Server Key Takeaways Chapter 4: Extending the Kubernetes API Kubernetes API Overview API Versioning API Groups Extension Points in Kubernetes API CustomResourceDefinitions API Server Aggregation Kubernetes Client Libraries Custom Resource Definitions and Controllers Operator Pattern in Kubernetes kubebuilder Framework Aggregated API and Extension Servers Key Takeaways Chapter 5: Scheduling Extensions Kubernetes Scheduler Overview Scheduling Framework Extension Points Configure and Manage Multiple Schedulers Scheduler Extenders Configuration Details Scheduler Extender API Filter Prioritize Preempt Bind Key Takeaways Chapter 6: Infrastructure Extensions Cloud-Native Infrastructure Storage Plugins Container Storage Interface (CSI) CSI Plugins in Kubernetes CSI Hostpath Driver in Action Network Plugins Kubernetes Network Model Container Network Interface (CNI) CNI Plugins in Kubernetes Calico CNI Plugin in Action Device Plugins Device Plugin API Development and Deployment of a Device Plugin Key Takeaways Chapter 7: Upcoming Extension Points Service Catalog Cluster API Key Takeaways Conclusion Index