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

Cluster information

It is always good to know which version of the Kubernetes server (API) is installed for a Kubernetes cluster as you might want to use particular features available in that version. To check the server version, run the following:

$ kubectl version --short
Client Version: v1.18.1
Server Version: v1.17.5-gke.9

The server version is v1.17.5 and the kubectl version is v1.18.1. Note that the -gke.9 bit of the server version is the internal GKE revision; as we mentioned earlier, for the book's purposes, a GKE cluster is used.

Important note

The kubectl version can be a more recent one; it does not really have to match the server version, as the latest version is usually backward compatible. However, it is not recommended to use an older kubectl version with a more recent server version.

Next, let's check the cluster server information by running the following command:

$ kubectl cluster-info
Kubernetes master is running at https://35.223.200...