Book Image

kubectl: Command-Line Kubernetes in a Nutshell

By : Rimantas Mocevicius
Book Image

kubectl: Command-Line Kubernetes in a Nutshell

By: Rimantas Mocevicius

Overview of this book

The kubectl command line tool lets you control Kubernetes clusters to manage nodes in the cluster and perform all types of Kubernetes operations. This introductory guide will get you up to speed with kubectl in no time. The book is divided into four parts, touching base on the installation and providing a general overview of kubectl in the first part. The second part introduces you to managing Kubernetes clusters and working with nodes. In the third part, you’ll be taken through the different ways in which you can manage Kubernetes applications, covering how to create, update, delete, view, and debug applications. The last part of the book focuses on various Kubernetes plugins and commands. You’ll get to grips with using Kustomize and discover Helm, a Kubernetes package manager. In addition to this, you’ll explore how you can use equivalent Docker commands in kubectl. By the end of this book, you’ll have learned how to install and update an application on Kubernetes, view its logs, and inspect clusters effectively.
Table of Contents (16 chapters)
Section 1: Getting Started with kubectl
Section 2: Kubernetes Cluster and Node Management
Section 3: Application Management
Section 4: Extending kubectl

Introduction to node pools

Cloud providers that have Kubernetes as a managed service support node pools. Let's learn what they are.

A node pool is just a group of Kubernetes nodes that have the same compute spec and the same Kubernetes node labels, nothing else too fancy.

For example, we have two node pools:

  • The default pool with the node-pool: default-pool node label
  • The web app pool with the node-pool: web-app node label

Kubernetes node labels can be used in node selectors and Node Affinity to control how workloads are scheduled to your nodes.

We are going to learn how to use Kubernetes node pools with Node Affinity in Chapter 5, Updating and Deleting Applications.