Book Image

The Kubernetes Workshop

By : Zachary Arnold, Sahil Dua, Wei Huang, Faisal Masood, Mélony Qin, Mohammed Abu Taleb
Book Image

The Kubernetes Workshop

By: Zachary Arnold, Sahil Dua, Wei Huang, Faisal Masood, Mélony Qin, Mohammed Abu Taleb

Overview of this book

Thanks to its extensive support for managing hundreds of containers that run cloud-native applications, Kubernetes is the most popular open source container orchestration platform that makes cluster management easy. This workshop adopts a practical approach to get you acquainted with the Kubernetes environment and its applications. Starting with an introduction to the fundamentals of Kubernetes, you’ll install and set up your Kubernetes environment. You’ll understand how to write YAML files and deploy your first simple web application container using Pod. You’ll then assign human-friendly names to Pods, explore various Kubernetes entities and functions, and discover when to use them. As you work through the chapters, this Kubernetes book will show you how you can make full-scale use of Kubernetes by applying a variety of techniques for designing components and deploying clusters. You’ll also get to grips with security policies for limiting access to certain functions inside the cluster. Toward the end of the book, you’ll get a rundown of Kubernetes advanced features for building your own controller and upgrading to a Kubernetes cluster without downtime. By the end of this workshop, you’ll be able to manage containers and run cloud-based applications efficiently using Kubernetes.
Table of Contents (20 chapters)
Preface

Using a Custom Kubernetes Scheduler

Building your own fully featured scheduler is out of the scope of this workshop. However, it is important to understand that the Kubernetes platform allows you to write your own scheduler if your use case requires it, although it is not recommended to use a custom scheduler unless you have a very specialized use case.

A custom scheduler runs as a normal Pod. You can specify in the definition of the Pod running your application to use the custom scheduler. You can add a schedulerName field in the Pod specification with the name of the custom scheduler as shown in this sample definition:

apiVersion: v1
kind: Pod
metadata:
  name: pod-with-custom-scheduler
spec:
  containers:
    - name: mutating-pod-example-container
      image: k8s.gcr.io/busybox
      command: [ "/bin/sh", "-c", "while :; do echo '.'; sleep...