The CKA Certificate From a Software Developer’s Perspective

Background

I have been working with Kubernetes (often referred to as “k8s”) for almost a year now. I have worked with various managed Kubernetes clusters and also deployed my own cluster that runs on several Raspberry Pis and serves as my personal sandbox where I can deploy my projects for a fraction of the cost of a cloud solution.

I’ve been interested in this technology for a while and for this reason, I thought it would be a good idea to get the Kubernetes certificate. Currently, CNCF offers two certifications for k8s: CKA (Certified Kubernetes Administrator) and CKAD (Certified Kubernetes Application Developer). There is a third one on the way:CKS - Certified Kubernetes Security Specialist. Even though I am a developer, I decided to take the CKA certificate. The reason is that the CKA cert is required to be admitted to the CKS exam later and I already knew most of the concepts required for CKAD as opposed to CKA, so I thought it would be more valuable to me.

Studying materials

Preparation for the CKA exam is straightforward: there is an official, publicly accessible curriculum that contains clear ideas about what you need to know to pass the exam. It took me about 3 weeks to prepare with the materials described below.

Udemy Mumshad Mannambeth’s CKA course

This course is recommended in almost every "How I passed the CKA exam" article, and for a good reason. Honestly, I think this is one of the best Udemy courses I have ever purchased. It covers every topic in the curriculum quite well and is accessible to both beginners and more advanced k8s users.

The course consists of two elements: videos explaining the concepts of k8s and further hands-on labs. The videos are short and concise, explaining very clearly the concepts of the k8s. For labs, you must login to an external website. For each lab, a new k8s cluster is created on which you need to perform certain tasks. I really enjoyed these labs and it was really convenient not to have to spin up my own clusters each time I wanted to practice something.

In my opinion, this course alone is enough to pass the CKA exam and I highly recommend it.

Kubernetes documentation

Whichever learning path you choose, you'll most likely be using the official docs often. You can use them during the exam, so be sure to get familiar with them.

The Kubernetes documentation is full of examples, helpful tips, and a variety of scenarios. Besides, the k8s documentation offers an interesting section called "tasks". This section shows how to perform individual tasks in Kubernetes. This is somewhat similar to the lab exercises in the Mumshad Mannambeth’s Udemy course, as many of these scenarios have the option of doing them using the Kubernetes playground.

Vim tutorial

This is a 30-minute video explaining the basics of Vim. The ability to find and replace certain phrases or navigate quickly through text is a very useful skill not only during the exam, but also in real-life situations.

Kubernetes the hard way

This one also appears very often in articles and posts about the CKA exam, especially older ones. K8s the hard way is a guide on how to configure a cluster without the use of tools that automate the entire process.

Previously, the CKA curriculum was broader and required things such as TLS bootstrapping, which is covered in this guide, but these are not required to pass the exam anymore.

If I had limited time I would skip this one, especially if I had no prior experience with GCP.

Killer.sh

Killer.sh offers mock exams for k8s certificates. I had planned to use them if I failed the first exam attempt in order to better prepare for the next one, but luckily it didn't happen.

The exam

The CKA curriculum has recently been slimmed down. The number of questions and the time to pass the exam as well as the threshold for passing the exam have been reduced. This is because the security section has been moved to a brand new exam (CKS).

The exam is 2 hours of performing tasks on live clusters. The tasks weren’t particularly hard, but you really need to be well prepared in order to accomplish all the tasks in time (the number of tasks ranges from 15 to 20, in my case it was exactly 20 tasks).

The only thing I wish I knew before the exam was how to set up the autocomplete feature for kubectl. For some reason it wasn’t already configured, so that was one extra thing I had to figure out by myself and because I don’t even remember when I did it last time I wasted a couple of precious minutes configuring that.

Conclusions

There is this debate whether certificates are a reliable way to verify knowledge or just a fancy badge that looks good on a resume.

In my opinion, CKA belongs to the group of “valuable” certificates. It taught me a lot about Kubernetes, but also about less obvious things, Such as linux networking or distributed systems; I also improved my Vim skills a lot. There is no option to pass this exam accidentally. You can’t just get lucky with your answers. You need actual hands-on experience with live clusters and I think this alone makes this certificate valuable.