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

Rolling back an application release

There are always cases (such as bugs in the code, the wrong Docker tag supplied for the latest release, and more) when you need to roll back an application release to a previous version.

This can be done using the $ kubectl rollout undo deployment nginx command followed by the get and describe commands:

Figure 5.2 – Deployment release rollback

The preceding output shows the version as Image: nginx:1.18.0, so the rollback was successful.

We can also check the deployment rollout history:

$ kubectl rollout history deployment nginx
1         <none>
2         <none>

We can also roll back to a specific revision:

$ kubectl rollout undo deployment nginx –to-revision=1
deployment.apps/nginx rolled back

Nice, we have learned how to roll back a deployment...