If you are here, I am pretty sure you already know what Kubernetes is, and how it is quickly changing the dynamics of cloud infrastructure around the world. Over the last few years, with increasing complexity of applications and focus on everything distributed, Microservices have come out as an effective way of designing your applications. Coincidently, introduction and rise of docker and containers have provided a natural deployment partner for microservices. And with rise of containers came Kubernetes – the management service for containers.
I have been playing around with Kubernetes for the last few years and have been aiming to complete the CKA certification for quite sometime. However, as the CKA is known for being a no nonsense, no MCQ exam, I had held my horses all this time. Then one fine day, I woke up and before my grogginess could wear off, I purchased the certification ticket and planned the exam in one month’s time. When I finally came to my senses, I realized that some amount of planning would be necessary if I didn’t want my $300 (the exam cost) to go down the drain. And hence I scoured the internet for a couple of hours and listed down my strategy for the exam. Before we get to that, let’s take a quick look on the exam and its pattern.
CKA Exam : Objective and Pattern
For starters, let me quote directly from http://www.cncf.io, the all-father of cloud native technology and examination authority for CKA about the exam objectives:
The online exam consists of a set of performance-based items (problems) to be solved in a command line and candidates have 3 hours to complete the tasks.
The Certification focuses on the skills required to be a successful Kubernetes Administrator in industry today. This includes these general domains and their weights on the exam:
- Application Lifecycle Management 8%
- Installation, Configuration & Validation 12%
- Core Concepts 19%
- Networking 11%
- Scheduling 5%
- Security 12%
- Cluster Maintenance 11%
- Logging / Monitoring 5%
- Storage 7%
- Troubleshooting 10%
The cost is $300 and includes one free retake.
Apart from the topics and their weightage in the test, there are 3 important points in the above exam description. First, the problems have to be solved in the command line. This means the test does not have any MCQ. All the questions are problems posed that need to be solved in the command line. Therefore, hands-on experience is vital in this exam. You need to have spent enough time working with kubectl commands to prepare you for this exam.
Second, the exam is for 3 hours! This is a little longer than most other exams, yet the nature of questions posed will ensure that the time is only just enough for the task. Hence, time management is crucial in this exam. This I believe is one of the shortcomings of the exam which aims to be a replication of real life kubernetes scenarios faced by the admins. The questions are much closer to practical issues in kubernetes but hardly ever are we pressed so tightly for time in order to solve issues in our day to day work.
Third, the exam includes one free retake. This comes as a great relief while planning for the exam. Given the different nature of the exam, it helps the candidate with one chance to understand the test and its dynamics with one more chance to redeem the certificate in case thing go south. This is helpful as the exam is considerably expensive for a retake.
How did I prepare for the exam
I had referred to a number of sources for the exam which I found mostly on internet and are as follows:
Kubernetes in Action: This is a great book written by Marko Luksa. It consists of 600 pages out of which first 300 are dedicated for basics of Kubernetes and next 300 are on advanced topics. I found Marko’s writing to be lucid and he has added enough hands-on examples that helped understand the concepts in depth.
Kubernetes Complete Tutorial – School of DevOps (Udemy): I had registered for this course quite some time back but was not able to complete it earlier. So when I decided to write the exam, I focused on completing this course rather than purchasing another one. I found this course to be helpful when combined with another source (for me in this case, the book by Marko)
Kubernetes the Hard Way by Kelsey Hightower: This github document is recommended by many exam takers and is popular for all the right reasons. Kelsey takes us through creation of Kubernetes cluster from the scratch with everything done manually – the hard way. This gives an in-depth understanding of cluster creation and working, and is very helpful not only for the exam but for overall understanding and appreciation of kubernetes setup.
Kubernetes-Certified-Administrator by Walid Shaari: Another github document which is a collection of various articles and videos on internet arranged as per the objectives in the exam. I found the videos pretty informative and the document also helped me get familiar with the kubernetes website.
Kubernetes.io: This is the official website of Kubernetes and is critical for the exam. Not just because this is the official comprehensive documentation on Kubernetes, but also because this website is allowed to be opened during the exam. Yes! CKA is an open book exam and you can open Kubernetes.io website (only that one though). Therefore, being familiar with the documentation on this site can save crucial seconds for you during the exam.
These are some of the sources I referred to during the preparation, most of which I found in articles written by other exam takers talking about their preparation. So I would highly recommend checking such articles online and going through some of the recommendations by fellow exam takers.
Kubectl cheat sheet: This is a great source for finding many commonly used kubectl commands. It will not be uncommon to find a question or two that could be directly solved using one of the commands in the list. Best part, it is in Kubernetes.io which can be accessed during the exam.
Be familiar with JSONPATH: This is also an important aspect of the preparation that will help you solve a question or two faster and save some time for more difficult ones.
Time management: There are 24 questions to be solved in 3 hours. That leaves a little more than 7 minutes per question. Often questions will be lengthy and complex in wording which could take upto a minute to carefully read and understand what has been asked of you. If you are not sure of the answer or the approach in the first two minutes, it is better to mark the question and move forward. There are some easy and medium difficulty level questions that could get missed if you end up spending a lot of time on difficult ones.
Selection management: The CKA passing score is 74%. Given the high passing percentage the focus should be more on answering questions correctly rather than attempting all the questions. Once you have attempted questions worth around 85-90 marks, it is prudent to carefully revise and check those answers rather than attempt the ones that are left, if you are pressed for time. Going back and rechecking the answers led me to correct some of the smaller mistakes that I had committed which otherwise would have gone unnoticed.
Finally, attempting some practice papers could be a great idea and could help you improve your time management skills during the test. I did go through some practice papers and my overall preparation was definitely better with their inclusion.
That’s all I have to say! I hope you have a wonderful time while preparing for this exam and I wish you all the very best for it.