Kubernetes in brief

Kubernetes is an open source production tool that allows you to manage applications that are built to run in a container. The implementation of this type of solution brings many benefits for the organization, e.g. it enables: implementation automation, seamless scaling and simplified management of distributed applications in dedicated infrastructures.

The K8s technology is steadily gaining in popularity, the best proof of which is the growing community of specialists in this area. It was this great interest that prompted the Cloud Native Computing Foundation (CNCF) and The Linux Foundation to introduce certification that formally confirms the ability to work in this technology.

Below, I will briefly describe my path to becoming a certified kubernetes administrator and provide some useful tips for those who want to take the exam.

Knowledge of documentation is the way to success

It is worth emphasizing that the Certified Kubernetes Administrator (CKA) exam is not easy. This does not mean, however, that it cannot be passed. The key to success is a solid preparation of theoretical knowledge, i.e. thorough knowledge of the documentation is necessary. Once you have mastered the theory, it will be time to put what you've learned into practice. You don't have to worry where to get the materials. The technical documentation available on the Kubernetes website, the Kubernetes Fundamentals LFS258 course or a well-prepared course on Udemy will be helpful.

The program required to pass the Certified Kubernetes Administrator includes the following topics:

  • Application Lifecycle Management 8%
  • Installation, Configuration & Validation 12%
  • Core Concepts 19%
  • Networking 11%
  • Scheduling 5%
  • Security 12%
  • Cluster Maintenance 11%
  • Logging / Monitoring 5%
  • Storage 7%
  • Troubleshooting 10%

There are several technical elements to take the exam:

  • Chrome or Chromium browser
  • very good access to the Internet
    Minimum 500Kbps download and 256Kbps upload
    Recommended 5Mbps or higher download and upload
  • a webcam with a minimum quality of 1080p
  • a microphone

The exact list of requirements is available in the Candidate Handbook, which can be found on the official website of The Linux Foundation.

Practice above all

It should take you approximately one month to solidly prepare for the exam, during which you should train every day. If you think one week, weekend or evening is enough - unfortunately I have to disappoint you. The material is quite extensive and the exam thoroughly verifies the acquired knowledge. The last week before the exam is the time that should be spent on repeating and consolidating tasks.

Below I will share tips that have worked for me:

Once you finish your course and feel more confident in the kubernetes' zone, it will be time to begin your exam preparation. If you want to pass, you should prepare yourself properly. Without good preparation, there is no point in trying to pass.

Exam details and exam time

The exam takes place only using the Chrome browser. On one screen there can be one window with the exam and a terminal through which the tasks should be solved. You can only have documentation open in the second window. The test consists of practice tasks only.

Important information about the exam:
• The exams are delivered online and consist of application-based tasks (problems) to be solved from the command line on Linux
• The exams consist of 20-25 tasks based on application performance
• Candidates have 3 hours (CKA) / 2 hours (CKAD) to pass the exam
• Exams are supervised via audio, video and screen sharing
• Results are emailed 36 hours after the end of the exam

Another good tip is to work with documentation beforehand. Remember certain elements, sections and learn to move smoothly through it. This will make it easier for you to solve tasks faster and more efficiently. It is worth getting acquainted with kubectl cheat sheet. Thanks to it, you will be able to find commands easily.

Basic requirements for using the terminal

Smooth use of the terminal increases the chances of passing the exam and will speed up the work on the next tasks. Additionally, it is good to:

  • Practice working with your favorite text editor (vim, nano, etc). It is worth checking your skills with useful shortcuts that you can use during the exam. Efficient copying and pasting will definitely be useful during the exam.
  • During the exam, you are allowed to have only one terminal window and one auxiliary window with kubernetes documentation open. Window multiplexing (tmux) may be a useful solution. It will definitely save you precious minutes.
  • Familiarize yourself with the subject of creating and managing system services, with the help of systemd. An important element here is kubelet.service which is responsible for communication with the node / master.
  • No tools may be used during the exam. A notebook may be a useful element. During the exam, you can save important notes and modify configurations or commands.

Ctrl + C and Ctrl + V are not allowed during the exam. New shortcuts that are described in the Candidate Handbook have been adapted. Below is an example of abbreviations for individual environments:

OS Copy Paste
Linux Select the text Middle mouse button
Mac ⌘+C ⌘+V
Windows Ctrl+Insert Shift+Insert

Build your own cluster

When building your own cluster, you can use the minikube in the form of one small node, which in most cases will be sufficient. However, in practice, in order to practice the configuration and administration well, you should put one main node (master) and several nodes on which the pod will work. The NoSchedule flag is automatically set when the root node is first configured. Thanks to this solution, the pods do not run on this node. It's best not to deploy application workloads to the primary server.

You can build your cluster using one of the solutions, e.g. using cloud solutions or virtual machines. Examples of such tools are the use of Vagrant and Ansible.

Chill out

First of all - take it easy, remember that if you fail the exam the first time, you have the option to try again. Due to the quite modern and so far unknown formula of the exam, which differs from the tests known to us, for example from the student days, we "waste" a lot of time finding ourselves in the new, test reality. Therefore, if you fail the first time - draw the right conclusions and use the experience gained to be even better prepared for the next approach.

I do not recommend attempting the exam without preparation, hoping that you might succeed. You only waste time that you could devote to study. If you prepare yourself honestly and reliably and master all the requirements, obtaining the certificate will not be difficult for you.

Wish you luck!