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 to a previous Helm release

In this section, let's see how to roll back to a previous version using the helm rollback command.

The helm rollback command is unique to Helm, and it allows us to roll back the whole application, so you do not have to worry about which Kubernetes resources need to be rolled back specifically.

Of course, when dealing with the release IDs of real-world applications, database schemas get changed as well, so to roll back the frontend application, you have to roll back the database schema changes too. This means that things aren't always so straightforward as they may seem here, but using Helm still simplifies some parts of the application release rollback process.

To run the helm rollback command, we first need to know the release revision we want to roll back to, which we can find with the following command:

$ helm history postgresql

The output of the preceding command is shown in the following screenshot: