Book Image

The Kubernetes Workshop

By : Zachary Arnold, Sahil Dua, Wei Huang, Faisal Masood, Mélony Qin, Mohammed Abu Taleb
5 (1)
Book Image

The Kubernetes Workshop

5 (1)
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

Labels

Labels are the metadata that contain identifiable information pertaining to the Kubernetes objects. These are basically key-value pairs that can be attached to objects such as pods. Each key must be unique for an object. Labels contain information that is meaningful to users. Labels can be attached to pods at the time of creation and can also be added or modified during their runtime too. Here is an example of how labels in a YAML file would appear:

metadata:
  labels:
    key1: value1
    key2: value2

Constraints for Labels

As noted earlier, labels are key-value pairs. There are certain rules that label keys and values should follow. These constraints exist because this way, the queries using labels can be evaluated faster by using optimized data structures and algorithms internally. Kubernetes internally maintains the mappings of labels to corresponding objects using optimized data structures to make these queries...