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

Patching a Kubernetes application

In this section, let's try to patch an application with Kustomize. For this example, we have a kustomize folder with the following files:

Figure 8.1 – Kustomize examples

The base folder has three files—deployment.yaml, service.yaml, and kustomization.yaml.

Let's check the deployment.yaml file by running the $ cat base/deployment.yaml command:

Figure 8.2 – The deployment.yaml file

In the preceding screenshot, we have the nginx deployment template, which we are going to use with Kustomize.

Let's get the service.yaml file's content by running the $ cat base/service.yaml command:

Figure 8.3 – The service.yaml file

In the preceding screenshot, we have the nginx service template that we are going to use with Kustomize.

As you can see, we are using the nginx deployment and service template again so it will be easier for you to...