Book Image

Certified Kubernetes Administrator (CKA) Exam Guide

By : Mélony Qin
4 (1)
Book Image

Certified Kubernetes Administrator (CKA) Exam Guide

4 (1)
By: Mélony Qin

Overview of this book

Kubernetes is the most popular container orchestration tool in the industry. The Kubernetes Administrator certification will help you establish your credibility and enable you to efficiently support the business growth of individual organizations with the help of this open source platform. The book begins by introducing you to Kubernetes architecture and the core concepts of Kubernetes. You'll then get to grips with the main Kubernetes API primitives, before diving into cluster installation, configuration, and management. Moving ahead, you’ll explore different approaches while maintaining the Kubernetes cluster, perform upgrades for the Kubernetes cluster, as well as backup and restore etcd. As you advance, you'll deploy and manage workloads on Kubernetes and work with storage for Kubernetes stateful workloads with the help of practical scenarios. You'll also delve into managing the security of Kubernetes applications and understand how different components in Kubernetes communicate with each other and with other applications. The concluding chapters will show you how to troubleshoot cluster- and application-level logging and monitoring, cluster components, and applications in Kubernetes. By the end of this Kubernetes book, you'll be fully prepared to pass the CKA exam and gain practical knowledge that can be applied in your day-to-day work.
Table of Contents (17 chapters)
1
Part 1: Cluster Architecture, Installation, and Configuration
5
Part 2: Managing Kubernetes
10
Part 3: Troubleshooting

Performing rolling updates and rollbacks

Rolling updates provide a way to update a Deployment to a newer version more effectively and efficiently. This way, you can update Kubernetes objects such as replicas and pods gradually with nearly zero downtime. In a nutshell, you may consider either using the kubectl set image command or going straight to updating a YAML manifest file. In this section, we will introduce kubectl set image, as it is very effective and handy to use in your actual CKA exam.

Rolling updates with kubectl

From here, we’ll go through the steps of rolling updates with kubectl:

  1. You can spin up a new Deployment, kubeserve, using the following command:
    kubectl create deployment kubeserve --image=nginx:latest
  2. You can use kubectl to update the container image as follows:
    kubectl set image deployment/kubeserve nginx=nginx:1.18.0 --record

Important note

--record flag records information about the updates so that it can be rolled back later...