CKA Experience & Tips

By Gaurav Gahlot | March 21, 2021

The result is out, and as of March 19, 2021 I’m a Certified Kubernetes Administrator. Everyone has got their share of challenges, experience, and tricks that worked for them. In this blog post I intend to share mine. I hope you find it helpful one way or another.


cka-certificate

Study Material

I took the CKA course by Mumshad Mannambeth available on Udemy. The primary reason to purchase this course was the number of recommendations it had. I had watched a few of his videos on YouTube and always found it easy to follow along. So, yes I would highly recommend this course to anyone.

However, this is not the only course in the market. There are plenty of them, and you may choose at your own will. At the end of the day, what matters the most is how much time you spend practicing different scenarios.

I can’t emphasize enough how important the labs are. Irrespective of the course you take, they all have labs and mock tests. Don’t skip any of them. They are all equally important.


My Mistakes (plenty of them :D)

  • I registered for the exam on March 17, 2020. Due a sequence of events and some personal reasons, I could not study at all. It was until late Jan, 2021 that I finally started to look into it.
  • Even though I started late, I wasn’t consistent. I would study one day and skip for another two days. Don’t do that. Be consistent and stick to a schedule.
  • I skipped labs. I thought it would be nice to go through all the lectures at once and then come back to labs. Not a good idea.
  • Completing a course is one thing. But you won’t know how much you understand until you take the mock tests. I, unfortunately, couldn’t take them.
  • Due to lack of preparation, I took time and decided to appear for the exam on the final day. If I would have failed the exam, I had no retake. So, prepare, practice and appear for the exam at least a week before the last date.


Do’s

  • The most obvious one - practice, practice and some more practice.
  • Take a lecture and do the lab that follows.
  • If possible, take the course first and when you think you are ready apply for the certificate exam. This gives you an year after you have completed the course. Enough time to test your skills.
  • Practice with complete commands, instead of binding an alias for like everything.
  • In each mock test, try to complete the test 15 min before the deadline. This gives you time to revisit the questions.
  • If you are a group, it would be better to purchase courses from different trainers. You can then share the courses within the group and that gives you more labs and mock tests to practice.
  • Monitor your time as you practice.
  • Do the labs and mock tests repeatedly (at least 3 times). Identify what is slowing you down and plan accordingly.


Don’ts

  • Don’t skip a single lab or mock test.
  • Don’t overwhelm yourself with an alias for everything.
  • Don’t panic if you are stuck, simply mark that question and move ahead.
  • Don’t practice on minikube or kind.
  • Don’t take the exam on last day (like I did).
  • Don’t have anything, other than your system, on the table at the time of exam.
  • Don’t overkill yourself with Kubernetes the Hard Way, unless you have time.
  • Don’t ignore the candidate hand book. Read it and follow the instructions.


Final Tips & Tricks

  • Practice only on a cluster setup with kubeadm. The exam clusters are setup with kubeadm only.
  • Do checkout the CKA and CKAD environment details and practice accordingly.
  • Don’t define an alias for everything. Instead, be smart and use auto-completion. It will be much more helpful and effective in the exam.
  • Here is how you can setup the auto-completion:
$ alias k='kubectl'

$ source <(kubectl completion bash)
$ echo "source <(kubectl completion bash)" >> ~/.bashrc

$ complete -F __start_kubectl k
  • The above commands can be found in the kubectl cheat sheet. And, yes you can use them (I used them myself), as they are listed in the docs.
  • As you do your labs, you must search the docs. Especially for resources like PV, PVC, Ingress, RBAC resources etc.
  • This actually trains your brain to remember the correct links, in case you need to refer the docs during exam. Saves a lot of time.
  • If you have time during preparation, take both the courses CKA and CKAD. This will surely help.
  • I suggest this because I had a question around Service Account while it’s actually a part of CKAD.
  • Get familiar with vi or vim. I’m not sure if nano will be available, so I would prefer vi or vim.
  • You don’t really need tmux or screen.
  • Get used to pasting text using mouse middle key. The mouse secondary key doesn’t work in exam environment.
  • Before you create an etcd backup, check whether the certs and endpoints you have used are correct. In order to do so, you can execute the etcdctl member list and check for errors, if any.


Useful commands:

Here is a nonextensive list of commands that you will definitely need during practice or exam:

# list running processes
$ ps -aux

# search for string in the output
$ ps -aux | grep -i 'string' 

# search for multiple expressions in the output (exp can be plain a string too)
$ ps -aux | grep -e 'exp-one' -e 'exp-two'

# get details about network interfaces
$ ifconfig

# list network interfaces and their IP address
$ ip a

# get the route details
$ ip r

# check service status and also show logs
$ service kubelet status -l

# restart a service
$ service kubelet restart

# reload the service daemon, if you changed the service file
$ systemctl daemon reload

# detailed logs of the service
$ journalctl -u kubelet

# list out ports, protocol and what processes are listening on those ports
$ netstat -tunlp


Conclusion

Though I made plenty of mistakes, I could clear the exam. This is because three days right before the exam, I pushed my limits and practiced. I also had some previous experience, which came in handy.

I hope this helps you plan and prepare better for the certification exam (CKA/AD/S). And I believe you will not repeat my mistakes. :D I will be happy to answer any other questions. Feel free to connect over LinkedIn or Twitter.

All the very best for your certification exam. Practice and prepare well. :)

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