Book Image

Mastering Kubernetes - Second Edition

By : Gigi Sayfan
Book Image

Mastering Kubernetes - Second Edition

By: Gigi Sayfan

Overview of this book

Kubernetes is an open source system that is used to automate the deployment, scaling, and management of containerized applications. If you are running more containers or want automated management of your containers, you need Kubernetes at your disposal. To put things into perspective, Mastering Kubernetes walks you through the advanced management of Kubernetes clusters. To start with, you will learn the fundamentals of both Kubernetes architecture and Kubernetes design in detail. You will discover how to run complex stateful microservices on Kubernetes including advanced features such as horizontal pod autoscaling, rolling updates, resource quotas, and persistent storage backend. Using real-world use cases, you will explore the options for network configuration, and understand how to set up, operate, and troubleshoot various Kubernetes networking plugins. In addition to this, you will get to grips with custom resource development and utilization in automation and maintenance workflows. To scale up your knowledge of Kubernetes, you will encounter some additional concepts based on the Kubernetes 1.10 release, such as Promethus, Role-based access control, API aggregation, and more. By the end of this book, you’ll know everything you need to graduate from intermediate to advanced level of understanding Kubernetes.
Table of Contents (16 chapters)

Writing your own CNI plugin

In this section, we will look at what it takes to actually write your own CNI plugin. First, we will look at the simplest plugin possible – the loopback plugin. Then, we will examine the plugin skeleton that implements most of the boilerplate associated with writing a CNI plugin. Finally, we will review the implementation of the bridge plugin. Before we dive in, here is a quick reminder of what a CNI plugin is:

  • A CNI plugin is an executable
  • It is responsible for connecting new containers to the network, assigning unique IP addresses to CNI containers, and taking care of routing
  • A container is a network namespace (in Kubernetes, a pod is a CNI container)
  • Network definitions are managed as JSON files, but stream to the plugin through standard input (no files are being read by the plugin)
  • Auxiliary information can be provided via environment variables...