CKAD exam preparation

Last week I approved the CKAD exam and now that I have some free time I want to share some resources and tips that were useful while studying and practicing.

Resources

First of all, it was really helpful to take a look at the current exam study guide to be aware of the topics included. During my preparation, I made these exercises over and over again, mostly to get comfortable with the resources that I rarely use

• https://github.com/dgkanatsios/CKAD-exercises
• https://github.com/bbachi/CKAD-Practice-Questions
• https://github.com/bmuschko/ckad-prep

I also took these courses to get some background knowledge and be able to have a deeper understanding of how Kubernetes works under the hoods.

• https://www.edx.org/es/course/introduction-to-kubernetes (Free)
• https://training.linuxfoundation.org/training/kubernetes-for-developers/ (Paid)

Regarding the Linux Foundation course, you may take advantage of a 30% discount that is currently available in the Linux Foundations Training page

Tips and tricks

These tips helped me to improve speed and performance while taking the exam.

• You won't be allowed to have any apps open but chrome and only with two tabs, one for the exam page and another one with k8s documentation. However, you may have bookmarks with helpful references within the allowed sites.
• kubectl run command only creates pods starting from version 1.18. Deprecated generators for deployments, jobs, and cronjobs were removed
• I found useful to invest some time at the beginning of the exam to properly set up the terminal:
  • Edit the .bashrc and add these aliases and sources:

    alias k='kubectl'
    source <(kubectl completion bash | sed 's/kubectl/k/g') # This enables autocompletion for the alias above
    alias kc='kubectl config set-context --current --namespace '
    alias kx='kubectl explain'

    Run source .bashrc to apply these changes to the current session
  • If you want to change the default editor (vim), you may add export KUBE_EDITOR=<your_editor> to the above file
  • If you're used to vim, create/edit the .vimrc file with these lines which makes your yaml editing less error-prone:

    set expandtab # use spaces for tabs
    set tabstop=2 # use 2 spaces for tab
    colorscheme desert # I found the default color scheme too hard to read

• No cheat-sheets allowed, so you must remember the above changes at the exam time
• I found useful switching context namespace before start solving the task. This way you don't need to remember to add -n <some_namespace> to every command
• When no namespace specified, use the default namespace
• Use kubectl edit only if you're confident about the change you're about to make. Otherwise, kubectl will prompt you again to the editing view
• --dry-run -o yaml are really helpful options to avoid writing boilerplate manifests.
• --export options is deprecated but still available to generate yaml files from existing resources without cluster-specific information
• Copy-on-select is not available in the web terminal. If you're used to selecting text from the terminal and paste it with right-click this won't work, so remember using Ctrl+Insert and Shift+Insert.
• Last but not least: practice, practice, practice

References

• The CKAD browser terminal
• How To Pass the Certified Kubernetes Application Developer (CKAD) Exam
• How to beat Kubernetes CKAD certification
• Webinar: CKA/CKAD