My Experience With the CNCF Certified Kubernetes Administrator Exam

Tips for cracking the Certified Kubernetes Administrator Exam

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I have recently completed the Certified Kubernetes Administrator exam and got a few pings on LinkedIn to share my experience, and therefore, I decided to write this blog down.

Kubernetes has gained a lot of traction in recent times, and a great way of showcasing your skills is to get certified. The Linux Foundation’s Certified Kubernetes Administrator is one of the most prestigious certifications you can aim for.

When I say prestigious, I mean it. One good reason for that is that the exam is entirely hands-on. There are no multiple-choice questions and nothing that you need to memorise.

It is therefore fulfilling, and if you love solving problems, you will undoubtedly enjoy the experience to the fullest.

Exam Format

There are 24 questions, 3 hours, and it is an open book examination. You have unlimited access to resources under https://kubernetes.io/docs/, https://github.com/kubernetes/, https://kubernetes.io/blog/ and their subdomains.

I like this aspect and respect to Linux Foundation and CNCF for this because they value people more for getting things done rather than cramming the exam materials.

In real life, it does not matter if you can remember how to write a manifest, or what commands you need to run. If you know how to approach the problem and understand the fundamentals, you can easily succeed. Most of us rely on google anyway, so it is pointless for requiring people to remember everything by heart.

Most questions are related to creating resources, troubleshooting cluster failures, setting up a kubernetes cluster and some general administrative abilities that any Kubernetes admin should have.

Read more about the exam format here

Level of the Exam

There are many murmurs around that CKA is a hard exam. I disagree with that statement because I think it is a fair exam. It is certainly not for everyone, and you need to know your craft before attempting this.

I felt it is more of an intermediate level exam containing questions with varying levels of difficulty.

Out of 24 questions, I found ten questions were straightforward, and if you have some experience creating Kubernetes resources, you can quickly solve them by referring to online resources.

The next ten were on an intermediate level. That required you have some degree of Kubernetes administration experience and you understand the fundamentals. Though the questions weren’t that difficult, you don’t get enough time to research and find the answers during the exam, but you can still manage by referring to the Kubernetes documentation.

The remaining four were more on the hard side. If you don’t understand how Kubernetes works, what are its moving parts, and what it is composed of, you will have a hard time solving those.

These questions also form a significant chunk of the exam with almost 20% weightage. So while you can still pass the exam if you are unable to answer them, the chances are very bleak if you get any of the other questions wrong.

Preparing for the Exam

As the exam is entirely hands-on, preparing for it requires a lot of practice. Practice and only practice can get you through. With 24 questions to solve in three hours, it’s just 7mins 30 seconds per question.

While that is enough if you are a seasoned Kubernetes admin, it might take you some time, if you have just started on your Kubernetes journey. The idea is to develop muscle memory, and you can only gain it by doing things over and over again.

The best way to utilise that time is to avoid creating yaml files when you can and use the imperative kubectl commands to generate yaml files. You should use aliases and practice with them during preparation. That will help you save a lot of time, and you can focus more time on challenging tasks.

Read the below article for some beneficial tips with the command line. These worked wonders for me in gaining speed and agility during the exam.

If you are a beginner in Kubernetes and want to understand the fundamentals, you can refer to the below course on Linux Academy. That is comprehensive and covers a lot of ground for you to understand Kubernetes architecture, resources and gain some hands-on practice.

Below is the closest you can get for a real exam. It is a mock exam with a terminal similar to what you would get in the actual exam. The questions are a tad bit difficult from the real one but are high in testing your preparation for the exam.

When I first attempted this, I only managed to score 60% in the first attempt, and that was an eye-opener. If you are an experienced Kubernetes admin, I would recommend you take this course and then focus on the weak areas, but don’t get too intimidated as the questions are more complicated.

The creator of killer.sh has also authored a few medium articles that you can refer to. That links to a GitHub repository with a Vagrant file that can help you set up the test cluster on your machine and you can then attempt the questions.

To gain more practice, you can solve the below labs. Though it focusses on CKAD, there is some overlap, and they are good enough to give you some real practice :

You can spin up a Kubernetes cluster in katacoda, or kubernetes playground for free. If you want to practice on a real cluster, you can always sign up for a free trial on GCP, or use Vagrant on your machine.

Learn about systemd and Linux command line commands such as grep, awk, and sed. They are vital as you require these skills in the exam, and some questions need you to use them. Know about Static pods as they are essential. Get an understanding of what they are, and how Kubernetes utilises them to run systemd managed pods.

Do the Kelsy Hightower’s “Kubernetes the Hard Way” guide at least once to gain an understanding of the internals of Kubernetes cluster, what are the components and how they interact with each other. Though you don’t get direct questions on setting up KTHW, knowing it helps you gain a fundamental understanding of Kubernetes

During the exam

The exam is online, conducted remotely on the convenience of your home or workplace. Ensure that you are in a quiet room and will not be disturbed during the three hours. The only requirement is that you need to have a computer with a webcam, a good internet connection, and a chrome or chromium browser with an extension installed.

You can log in 15 mins before your scheduled exam appointment, and you should start the exam no longer than 15 mins after. The proctor checks your identification (you can use any government-issued identification card such as a passport or a driving license). They then ask you to pan your webcam across the entire room to make sure they are satisfied that you are not involved in any unfair practices.

Once the proctor is satisfied, they will start the exam, and time it. Breaks are allowed during the exam period but only for genuine reasons. The time continues during the break. You can open only one additional browser tab apart from the exam environment to access resources from the allowed websites.

Some tips that helped me a lot

  1. Focus on easy questions first. The idea is to get as many marks as possible in the least time. If you think you don’t know the answer to the problem right away, skip and move to the next. You can flag items that you are unsure of or have skipped so make use of it,
  2. Always switch contexts before starting any question. That is required as you may do stuff in the wrong cluster. Answering a question correctly in the incorrect cluster gives you zero marks.
  3. Focus on questions with higher weightage first. The whole idea is to obtain passing marks before you run out of time. So aim for the highest you can get by answering fewer questions. Some of the more weighted questions are as easy as less weighted ones and almost take the same amount of time.
  4. Revise your answers in the last half hour. Don’t aim for answering all the questions, but aim for answering the questions correctly. Revision is a key to ensure that you have responded to the questions correctly and haven’t made a silly mistake.
  5. Pace yourself. If a question is taking more than 5 minutes, skip it and move to the next. You won’t finish otherwise. Most people fail in the exam because they run out of time.

About the Exam Environment

You are given a browser-based Linux terminal with questions on the left-hand side of the screen. There are 6 clusters in total, each catering to a specific set of problems. You need to solve all questions in the command line, and switch contexts between multiple clusters.

The questions are arranged in such a way that there is minimum switching required, but you need to be cautious where you run the commands. A small mistake can cost you dearly as the exam is graded automatically.

The intention of the exam is not to trick you. That means the instructions are clear and concise, and they will provide you with only the relevant information without any verbosity and assumptions. For example, the questions will mention what resource you should create, the name of the resource, the name of the container etc. You only need to use relevant information to meet the objective of the question.

The browser-based terminal is ok, but you need to be cautious about copying and pasting. As I am used to Putty, I made a lot of errors copying stuff as in Putty select text copies it and a right-click pastes it, but in the exam environment you will have to select the text, do a Ctrl+Insert to copy, and then Shift+Insert to paste. With my muscle memory, it was getting annoying, and I made a few mistakes during the initial 30 minutes before I got used to it.

You can copy relevant information from the question section by just clicking on the information such as pod name, container name etc.

Don’t try to copy-paste from the online documentation. Instead, you can wget yaml files from there. I referred to Kubernetes blogs for some of the questions and those contained links that you can copy and wget within the terminal. You can then vim those files and edit the yaml according to your liking.

Though the official exam guide suggests that only limited copy-paste is enabled, I faced no such issue during the exam. It is best to avoid that though because vim is just not that user friendly within the browser terminal and kind of misaligns during the copy-paste.

There is also a tiny notepad within the exam environment which you can use as a temporary staging area for your copy-pastes, or for keeping track of questions and the number of marks attempted.

Lastly, kubectl everything away. That is the key, and you need to get used to it. Time is precious, and you should not waste time writing yaml files, instead kubectl dry-run it.

After the exam

After you’ve completed your exam, the grading process starts and your results will be available after 36 hours of exam completion. I received my score precisely 36 hours after the exam, and I was thrilled to see that I have cracked it at 94%. As the exam is practical, it was a fulfilling experience for me, and I am glad I made it. Just in case you miss in the first try, you get a free retake from the Linux Foundation. So wish you all the best in your CKA journey!

Certified Kubernetes Administrator | Cloud Architect | DevOps Enthusiast | Connect @ https://gauravdevops.com | https://freedevtools.net

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