Platform Engineer & Automation Enthusiast
A couple of weeks ago I passed the Certified Kubernetes Administrator (CKA) exam with 7 days of prep. Here’s how I did it.
To pass the CKA in 7 days you need to be purposeful with your prep. This doesn’t mean living at your desk 24/7; I allocated my usual working hours to studying. It just means being an active student when you’re learning, give it your full attention and the rest will fall into place.
Resources I used:
I spent about 90% of my prep time going through the Udemy course. It has a great, clear structure (video explanations followed up by practice exercises), and if (like me) you struggle to watch videos at normal speed, you can speed things up.
It also includes 3 mock exams at the end of the course that I found to be the best representation of what you sit in the actual exam. Once you’ve attempted one of the mocks, go through the solution videos for any questions you struggled with. I cannot emphasise enough how valuable this is.
It helps you to develop a workflow for different types of questions, and in some cases I came away with a new imperative command or flag that saved me precious time in the exam.
I read a few Medium articles that told me I needed to go through Kelsey Hightower’s Kubernetes the Hard Way (KTHW) at least five times(!) to pass the CKA.
I went through this just 1.5 times and that was enough. I say 1.5 because on my first attempt I flew through copy pasting commands without giving much thought to what I was doing — you need to invest some real concentration to get value out of this exercise.
KTHW was great for consolidating my knowledge of k8s configuration, and it’s definitely beneficial to be comfortable creating a k8s cluster from scratch. However, if your goal is to pass the CKA as quickly as possible you do not need to repeatedly go through this exercise.
Instead, when you do go through KTHW, try to familiarise yourself with the environment, the location and format of the config files, and how you interact with
commands. The exam value gained here is in the debugging style questions, a skill that isn’t so well covered in the Udemy course.
The CKA exam gives you 3 hours to answer 24 questions, an average of just 7.5 minutes per question. Those stats can seem scary at first, but good exam technique can give you a lot of that time back.
Tools I used in the exam:
- vim - kubectl - kubeadm - systemctl & journalctl - nslookup
A lot of people mention using
, I didn’t, but it can definitely be useful for some split screen action amongst other things - you're given a single terminal in the exam.
You’re allowed to have one page of the official Kubernetes documentation open during the exam. If you’ve spent any time looking through the Kubernetes docs already you’ll know that they’re extensive; and a decent amount of time can be spent looking up keywords in their internal search function.
Instead, when you’re going through the mock exams, bookmark all of the pages that you find yourself referring to in a dedicated 'k8s' folder. This will help you navigate quickly between pages without any unnecessary time loss. I went into the exam with at least 20 pages of documentation bookmarked.
You’re going to be using a lot of imperative commands in this exam, and all that typing time adds up. Write yourself some aliases for the most common kubectl commands and add them to your
file. Make sure you do your practice tests with these commands so that they come naturally in the exam.
Here are some of the aliases I found most useful:
alias kc='kubectl create -f' alias kr='kubectl run' alias kg='kubectl get' alias kd='kubectl describe' alias ke='kubectl explain'
At the start of every question there’ll be a
command setting the correct context for your answer. Make sure you run this command every time you open a new question. While the majority of questions use the same context, there are a few that don’t and you can trip yourself up if you don’t do this by default, especially when skipping back and forth between questions.
The exam environment comes with built-in flagging functionality. If you read a question that you don’t immediately know how to answer, flag it. Flagged questions will be highlighted in your question list, allowing you to return to them quickly once you’ve finished answering the ones you’re comfortable with.
Along with flagging capabilities, the exam provides you with a built-in notepad. Make use of the notepad to keep a running tally of questions you’ve answered and their percentage value (this number is given to you with each question).
I like to keep a list of the questions I haven’t answered and their associated percentages too. It’s a good way to inform how you should prioritise your time, particularly towards the end of the exam. If you're cutting it fine with the 74% pass mark, your time is probably better spent on a 7% question, than a 2% one.
If you have to create a YAML file when answering a question, for example a Pod config file, make sure you name the file according to the question number.
user@ubuntu:~$ ls 01.yml 09.yml 19.yml 02.yml 12.yml 22.yml 04.yml 15.yml
There won’t be a file for every question, but it will make things a lot easier when you come to checking your answers at the end of the exam. Which is a nice segue into…
There’s a decent chance you will have made mistakes, I did. Usually it’s something small (I missed a label on one of my Pods), but small mistakes will still cost you 100% of the marks. It’s worth allocating some time to check your answers.
Keep in mind, it’s better exam economics to spend your final minutes checking answers to the questions you do understand, rather than staring at that one scary unanswered question you don’t (you likely won’t pick up any marks for this one anyway). I answered 22 of the 24 questions presented in the exam and passed comfortably.
Work hard to prep in the days leading up to your exam, go through the Udemy course and then hit the mocks, review the solutions and topic areas of any questions you struggle with and make sure your documentation bookmarks are organised nicely.
As a rough guide, once you can get through the Udemy mocks with a high pass mark and finish comfortably within the time limit, you’re ready.
Oh, and make sure you've eaten before you start your exam - three hours is a long time and snacks are banned!