In July 2022 I got my first Kubernetes certification: CKAD (Certified Kubernetes Application Developer). In November 2022 I got the second Kubernetes certification: CKA (Certified Kubernetes Administrator).
In this post, I want to give a few tips about study preparation and about the final exam.
Following suggestions of a couple of colleagues, I have studied "everything" about Kubernetes on some Udemy courses, all of them of Mumshad Mannambeth and his company KodeKloud.
Keeping in mind that at the beginning of the year I was an absolute beginner on containers, Docker and Kubernetes, I really needed to start from the basics.
The Udemy courses that I have bought are:
- Docker for the Absolute Beginner - Hands On - DevOps
- Docker - SWARM - Hands-on - DevOps
- Kubernetes for the Absolute Beginners - Hands-on
- Kubernetes Certified Application Developer (CKAD) with Tests
- Certified Kubernetes Administrator (CKA) with Practice Tests
Mumshad is very good in explaining all concepts with slides, metaphor, samples. There are also many labs, hosted in KodeKloud.com. But having bought the Udemy course, you don't have to pay anything for these labs.
And as once bought, the Udemy course is available "forever", the same is true for these labs.
Also: after completing the course for my second certification (CKA), I've realized that my previous completion score in Udemy for the previous course (CKAD) is now only 93%. Why? Because Mumshad continues to take care of his courses, adding constantly new content and updating existing one. Big shoutout to Mumshad!
Personally, I have done each course, and before giving the exam, I have repeated all the CKAD labs. The same for the second CKA exam.
While the courses above are totally fine to prepare for the exam, I got also suggestions about other training material, that I report here just for completness:
- The YouTube channel Alok Kumar contains many videos containing questions similar to the CKA exam.
The videos are well done, but in my opinion don't give any value compared to the Udemy courses. Also they just focus on questions and answers, but don't want to explain the full topic. As they are for free, they are still a good way to refresh the CKA topics.
- The YouTube video Kubernetes CKA Simulator Practice Test | Killer: this 4 hours video executes an exam on the Killer.Shell exam simulator. Honestly I didn't have time to watch this video (yet), but I plan to do it in the near future.
Additional notes on preparation
Apart from studying Kubernetes in the proper way, there are a few tips that I would like to recommend, during the study phase.
First of all: during the exam is allowed to use the Kubernetes offical documentation, so don't spend time and energy learning long and tedious YAML and command line parameters.
Often, it's more convenient to remember where some topics are found in the documentations - like in real life, in the end.
Second: to save time, be smart and have confidence in using the kubectl command. For example, often you can start typing a command, and then add --help to get the additional parameters.
Even when something can't be done via kubectl, very often you can start with 80% of the goal, use --dry-run=client -o yaml to have a first draft in YAML, and then complete the file in vi.
About the text editor vi: it is required to know it, as this is the editor available during the exam.
The basic command that I know are:
- dd - to delete the current line
- d4d - to delete 4 lines (or choose the number you need)
- x - to delete the current character
- i - to enter in insert/edit mode; exit with ESC
- / - to search for text; search again with 'n'
- :wq - to save and exit
- :q! - to exit without saving
- :w - to save without exiting
- :q - to exit when no save is necessary
Scheduling the exam
Giving the exam - PSI
At the day of the exam, 30 minutes before the planned time, you can go to your Linux Foundation dashboard and press the button "Start exam".
This will download the PSI browser on your computer and run it.
The browser will allow the proctor from PSI to see your computer screen, yourself (via the webcam) and hear you (via the microphone).
Then, a proctor will reach out to you, will check your room, literally from the ceiling to the floor under the table.
Clearly you are not allowed to have phones, smartwatches, or anything in the ears.
In my case, I've booked full meeting rooms at my work place, because I think that I would have not been able to have the empty environment required for the exam in my home.
Two important things to remember during the exam:
- bring your passport: even if it is not stricly required, in my first exam I brought my ID card, my work permit, my driving license... The proctor had problems with all of them, even if all of them had my photo and my signature (and of course were official documents). Clearly they are more used to use passports, and in fact the authentication with passport has been much quicker.
- bring a laptop charger: even if the authentication phase should last 30 minutes and the exam two hours, I always struggled with the proctor and the technical support... so the exam in reality lasts much longer.
About the PSI browser: while I understand the need of a tool to control the exam environment, I would have preferred if I would have been able to use my browser and the tools in my computer. The monitor space in the PSI browser is limited (on the left side there is a pane with the questions) and it is not allowed to have external monitors. The room space in your virtual desktop is really limiting and it slows down your work quite a lot.
Also, some key combination don't work in this environment. For example, to navigate the Kubernetes documentation the installed browser is Firefox. There, Ctrl+F to find text doesn't always work, and to search additional occurrences of the text is problematic. So, you need to scroll manually even long pages, and again, this takes time.
Also some note on the PSI proctor and technical support: it's clear that they manage many exams at the same time, of different technologies and customers. Even if they would like, they are totally unable to answer any question you might have during the exam.
That is fine, but when you have some technical problem, they call a technician, who spends 20 minutes asking standard questions just to fill-in some form, and then asks you if you want to move the exam to another time.
All of this superficiality makes that every possible inconvenience takes really a lot of time to be solved.
Concluding about PSI: I really don't like their testing environment and methodologies. I hope that in some time the Linux Foundation will replace them.
The real exam - Linux Foundation
This section is instead dedicated to the real exam - so the questions you are required to answer.
Here there are no long texts with long stories about fake companies and their issues, where you have to interpret what they are asking to you... no, nothing of that.
Here the questions are very direct, like "do this and that", or "check why this is not working". How you do it, it's your choice. You can use kubectl, YAML, you can have learnt everything by heart, or need time to use the docs. You have complete freedom, important is that you reach the required goal - that I want to repeat, is really very clear and doesn't give opportunity for misunderstanding.
Concluding: as much as I don't like PSI, I really like the structure of the exam, with concrete questions and the possibility to use the official documentation.
Kubernetes is an hot topic now.
I am very happy having studied it, also with the goal of the certification.
The certification by itself is really fair, as it tests your knowledge without too many interpretations or long use cases to read.
The wrong note in this idyllic picture is PSI. I hope that the Linux Foundation will receive enough negative feedback, that will push them to find a better alternative.