The best of bad advices about CKA
You will find a lot of articles with good tips on how to ace the CKA exam. You should definitely read them! When preparing for the exam, it sure helped me a lot. But as I am now certified, in retrospect, I can say some of these advices may not be worth your time.
In this article I will focus on tips I would call discussable: they do not give you a real competitive advantage and may even impediment your success. Let’s start!
#1 You need prior experience with Kubernetes
This is simply not true. Accounts of people with 1+ years of experience on Kubernetes that barely pass the exam make me wonder what they really did during their time with the technology.
Of course, prior experience is good and most experienced Kubernetes administrators or developers will only need some refresh on key areas. But even if you did not use Kubernetes you can pass the exam by focusing your study on the certification curriculum. More on this below.
#2 You need to use a course or training
The exam is performance based. More precisely, task based. You are given a terminal, a Kubernetes installation and should clear each question by executing commands to reach a given state. What you need to succeed:
To understand the general architecture of a Kubernetes cluster and what are the main componentsKnow how to navigate the official documentation on kubernetes.ioDo at least once every tasks of the official documentation
The understanding of the Kubernetes architecture required for the exam is quite basic, you should not be afraid.
What is asked of you during the exam boils down to tasks from the official documentation. There’s no need to know how to do every tasks by heart as the official documentation is allowed during the exam. You only need to find quickly the task page matching the question.
You will say: “But I need to know complex things like how to troubleshoot a non working cluster!”. Yes you need to. And there is task for it in the documentation. There is a task for everything in the doc 🤹♀️
Some courses offer you interactive sandboxes to operate a real Kubernetes cluster. It’s a really nice feature! However, do not forget you can also practice on a cluster for free using Katacoda for example.
#3 Time is short
You have 3 hours to clear every (24) questions. If you do the maths, it means 7 minutes and 30 seconds by questions. You may think it’s short but please do not stress about it. Most problems are completed in less than 5 minutes if you do the following:
- Use the provided kubectl command to be sure to operate in the right context!
- Read the questionUnderstand the required task by identifying key words (“create a pod”…)
- Lookup the corresponding task in the documentationDo it given the documentation and the question specifications
- Repeat
It’s as simple as that. You will find that questions are roughly in order of difficulty. Last 3–4 questions are more time consuming so you should spare time on the first 20-ish questions.
If you are really out of time, look at the score indication: every question is worth a percent of the score and you need 74% to succeed. You can pass without doing all the questions. If by reading the question you can’t identify the matching task, do not linger and go forward.
#4 You need to do Kubernetes the Hard Way
People are crazy about this one. What you can read: “I did KTHW 4 times to be sure to grasp every details”, “You need to do KTHW to understand Kubernetes architecture”, “I learn commands from KTHW by heart”.
It’s wrong. KTHW is a nice thing to do to have a feel about configuring a cluster using bare VM. But:
- Roughly 70% of time in KTHW is spent on creating and distributing certificates, not the best learning activity
- The focus in the official Kubernetes documentation is on kubeadm which makes setup-ing a cluster easy
- In real life, most of you will use a managed Kubernetes solution, so not the most realistic scenario
Don’t read me wrong: there’s no harm in doing KTHW. But please don’t go crazy and don’t waste your time overstudying it. Instead, be sure to know how to operate a cluster with kubeadm.
#5 You need to install tmux or any other utility to succeed
During the exam, you have a web console. You cannot open any additional terminal. Some questions may require you connect to other hosts.
As you have sufficient privilege to install any utilities in your terminal, people recommend the use of tmux or equivalent as a lifesaver. If you are familiar with such solution, go on, install it during the exam.
But my experience is you don’t spend lot of time cycling between different machines. Connecting to another host is required only for a few questions and it’s very often a one way operation. Not worth the time investment IMO.
Instead, things 100% worth installing:
- Your favorite editor (if it’s not vim)
- Kubectl bash completion:
echo 'source <(kubectl completion bash)' >>~/.bashrcConcluding thoughts
CKA is not so hard if you focus your study properly. Don’t forget it is the interest of people who pass an exam to make it appear as hard as possible to hype their accomplishments 😎
Hey even if you should fail, do not forget the free retake! By learning from our past mistake, we make future success a certainty.
At last, please note that starting September 1st 2020, the exam will last only 2 hours. The curriculum stays roughly the same with topic weights adjusted here and there. There is no reason to think the exam will change drastically so everything outlined here will stay relevant. Good luck! 👍