This blog-post was originally published on Medium by our colleague Anurag Raut.
There is no doubt about the fact that the adoption of Kubernetes is growing exponentially in the industry, and it is important for us to be prepared to establish credibility and value to cope up in the market. CNCF makes it possible to authorize us with the knowledge of Kubernetes with certifications like Certified Kubernetes Administrator (CKA) and Certified Kubernetes Application Developer (CKAD) to stand out in the crowd.
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I recently took the CKA and CKAD exam and successfully passed the exam in the first attempt. I would like to share my experience and help you in getting prepared for the K8s certification.
Unlike other typical certifications, Kubernetes certifications are practical hands-on exams. So you need to spend time practicing hands-on labs. Once purchased you can take the exam within the 12 months. Enough time to prepare and attempt both CKA and CKAD exams.
The very first question I had was; should I go for CKA or CKAD?
- If you just need to try Kubernetes Certification and get one quickly, I’d say go for CKAD. As it’s easier to prepare and crack, compared to CKA.
- If you really want to learn Kubernetes well, go for CKA. I think all system administrators and operations engineers should target CKA.
- If you prepare for CKA, CKAD will be just an add on with some additional topics.
- YAML/JSON knowledge: All Kubernetes objects can be created via YAML or JSON files. But YAML is widely used since its simple. So it is good to have YAML knowledge.
- Linux Knowledge: For the ones who never worked on Linux based OS, it’s highly recommended to take Beginners course of Linux, knowledge of networking in Linux is also required to some extent if you are going for CKA.
- Vim editor: While preparing for the exam, you will quite often need to create and modify files. If you are new to Vim, check below:
Practice Vim: https://github.com/damassi/learn-vim
Vim cheatsheet: https://devhints.io/vim
- Docker Knowledge: As Kubernetes is a container orchestrator; before you start preparing for CKAD or CKA, having prior knowledge of docker is a must. If you are new to the container world, I’d advise you to take a course on one of the following learning portals: Udacity, Udemy, edX.
- There are many courses available at Udemy, Linux Foundation. I took the course from Udemy by Mumshad Mannambeth. You can also find his course at KodeKloud. It is a very comprehensive and in-depth course that contains all the needed information and practice labs.
- Since this exam is all about solving problems, you need to practice a lot. Practice each topic of your related exam. You can use katacoda playground or at play-with-k8s labs. Katacoda also has several scenario-based topics that you can practice.
Practice 150 questions, this will give a good hands-on for the exam.
- Familiarise yourself with tools such as openssl, journald, systemd, etcdctl (for managing etcd).
- The obvious recommendation is to spin up the Kubernetes cluster the hard way. I did it on Azure by spinning up low-cost virtual machines. You can choose any cloud of your choice to practice cluster creation. Make sure to bring it down after the use or delete once your job is done, else it will incur unnecessary cost.
- In the exam, you are allowed to refer to Kubernetes documentation, Kubernetes blog, and GitHub artifacts of Kubernetes. So you should be familiar with the documentation; of course, the documentation is of no use if you do not have a good understanding of the concept and know where to find the exam topic while you need it in the exam.
- Practice multiplying kubectl commands. Try running nested kubectl commands to perform some operations and get some output.
- Make sure to practice with the latest version of the Kubernetes release. Currently, the exam is using Kubernetes v1.18 Release as I am writing this blog. Check the k8s exam guide before your exam schedule to know the version used.
- Below are the 3 important bookmarks, use it while learning and practicing labs:
Tips & Tricks:
- Time Management: Managing time is the key to crack the exam. For CKA you get 24 questions to be answered in 3hrs and for CKAD 19 questions in 2hrs.
- Setup autocompletes in bash into the current shell when you start the exam, you may use shorthand alias for kubectl (alias k=kubectl).
I have read at other places to use tmux to be efficient, trust me you don’t need it. If you are not familiar avoid using it.
- Not all questions are equal weight, so do not spend too much time at one question. If you get tricky questions, flag it and move to the next question and try to attempt all the questions.
- CKA has 6 different clusters and CKAD has 4. Related questions are integrated into one cluster. Make sure to change the cluster context once you complete and move the next question.
- In some questions, you will need to ssh another node in the cluster and elevate permissions. After performing your task, be careful while exiting from the elevated role and the node, sometimes you try to be quick and may come out of the base node which can lead to re-login the base node and cost extra time. You need to always return to the base node before attempting the next question.
- You are not allowed to use pen and paper, you can use the inbuilt notepad to note any command or save any information you want.
- Use kubectl to create resources (such as deployment, service, cronjobs, etc) instead of creating them from manifest files. It saves a lot of time. If you need to make further changes, save the manifest file for the resource you created using kubectl, modify accordingly and re-apply. Alternatively, you can as well use kubectl edit <resource> to modify the resource spec.
- Know that you have one free re-take if you didn’t clear the exam in the first attempt. Thankfully, I didn’t need it and I wish you don’t need it as well but knowing this will definitely help you to calm down during the exam.
At last, since the exam requires concentrated effort for 3 hours(CKA)/2 hours(CKAD) and is straining both physically and mentally, book the best time of a day and come with a relaxed mind.
How do I register for the exam?
Please leave a comment if you have any questions. I will be happy to answer.
I wish you the best of luck in getting your certification!