Kubernetes Certification CKA – readings and advices about how to obtain it

I’ve recently obtained the official “Cerfified Kubernetes Administrator“, some people write me on linkedin asking opinions about how to pass the exam, for this reason i’ve decied to share my experience and write down some advices and userful resources. Every CKA’s candidate must sign an NDA, so i can’t spread specific details.

If you don’t have specific knowledge about container tecnologies and docker, read the O’Reilly’s book “Docker: Up & Running“, the exam doesn’t require specific knowledge about docker but, since Kubernetes is an orchestrator for containers, this is a needed base.

IMHO the best book about k8s is “Kubernetes in Action” , it covers a lot of aspect about this software and it’s very detailed, you don’t need to read it from the beginning till the end, some chapters of the “part 3” are not required by the exam.

In parallel of your readings, you need to do practice, so open an account on a cloud provider that provides managed kubernete’s clusters, by now there’s a lot of providers that support it, the one that it’s considered the best about k8s is Google Cloud Platform. Sign in an account, insert your credit card and you will get free 300$ to be used within 1 year.

First make practice with clusters already created by provider and managed with GKE, you need to understand well how to work with Pod, Deployment, Service, ConfigMap ecc… you need to get very comfortable with the command line kubectl since this is the k8s’s principal CLI.

After that period, learn how to install a cluster: create 3 vm (you can use the g1-small with preemptible feature so you will consume small credit), connect via ssh and create cluster formed by 1 master and 2 worker with kubeadm.

Connect to the servers, check the k8s’s systemd units, where the logs are located and …. broke it! a part of the exam will be about how to do debugging on a broken cluster. After you have fixed the cluseter, destroy the virtual machines, create other 3 machines and re-broke it on another way! 🙂

During the exam you will be allowed to use only the official documentation, so during your tests get accustomed to use https://kubernetes.io/docs , avoid to use StackOverflow&c.

The environment cka-practice-environment is a good test, you can easily use it with docker-compose. The advices in this document are useful, and this “commented curriculum” is useful as a recap before the exam. At the end go through “Kubernetes the Hard Way” to learn how to configure by hand a cluster and understand the details of every component.

When you are ready, schedule the exam. It’s a practice exam that will last 3 hours max, as every Linux Foundation/CNCF’s exam it’s a remote one, you need a computer with Chrome and a particular extension installed, this extension will share your webcam, desktop and the microphone. When the exam will start, you get a Linux console with kubectl already configured with 6 clusters, before every question will be written the kubectl config use-context command to connect to the correct cluster. T all’inizio di ognuna delle 24 domande vi verrà indicato su quale cluster dovete agire tramite kubectl config use-context.

The exam is formed by 24 questions, a minimum score of 74% is required to pass it, the three hours are enough to complete all the exercises, the exam is rigorous but can be passed by anyone who has prepared with commitment.

Good luck!

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