Certified Kubernetes Application Developer (CKAD) Study Notes

Official CKAD exam page

https://www.cncf.io/certification/ckad/

2Hrs | Cost $300 | Online Exam
K8s version 1.20 (Jan 22, 2021)

CKAD Curriculum

Updated exam curriculum for v1.20
https://github.com/cncf/curriculum/

Domain	Weight
Core Concepts	13%
• Understand Kubernetes API primitives
• Create and configure basic Pods
Multi-Container Pods	10%
• Understand Multi-Container Pod design patterns (e.g. ambassador, adapter, sidecar)
Pod Design	20%
• Understand Deployments and how to perform rolling updates
• Understand Deployments and how to perform rollbacks
• Understand Jobs and CronJobs
• Understand how to use Labels, Selectors, and Annotations
State Persistence	8%
• Understand PersistentVolumeClaims for storage
Configuration	18%
• Understand ConfigMaps
• Understand SecurityContexts
• Define an application’s resource requirements
• Create & consume Secrets
• Understand ServiceAccounts
Observability	18%
• Understand LivenessProbes and ReadinessProbes
• Understand container logging
• Understand how to monitor applications in Kubernetes
• Understand debugging in Kubernetes
Services & Networking	13%
• Understand Services
• Demonstrate basic understanding of NetworkPolicies

Kubernetes Documentation

• Main Documentation page:
  https://kubernetes.io/docs/

• Cheat Sheet:
  https://kubernetes.io/docs/reference/kubectl/cheatsheet/

• kubectl Command Reference https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands

• One-page API Reference for Kubernetes v1.20
  https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.20/

CKAD Training

• Great course from "a Cloud Guru":
  https://learn.acloud.guru/course/certified-kubernetes-application-developer/
  by William Boyd

CKAD Lab Exercises

• killer.sh_ https://killer.sh/ckad

  • not free but worth it
  • 29.99€ for two CKAD sessions of the same mock exam

• Dimitris-Ilias Gkanatsios
  https://github.com/dgkanatsios/CKAD-exercises

• Benjamin Muschko https://github.com/bmuschko/ckad-prep

CKAD Exam Tips

• Time management is key!
  • You have 15-20 performance-based tasks to perform in 2 hours, so an average of 6-8 min per task. Some tasks are easy but some others will take much more time.
  • Get all questions done:
    • Make sure to go through all 15-20 tasks
    • Get all the easiest tasks done first!
  • Never get stuck:
    • If a task is seems difficult or it's taking you more than 2-3 min, then flag it and keep moving to get any easy task done first.
    • Then go back to each of the flagged tasks afterwards.

• Setup kubectl alias and autocomplete
  • source <(kubectl completion bash)
  • alias k=kubectl
  • complete -F __start_kubectl k

• Setup an shell variable to easily generate resource specs in YAML format:
  • export do="--dry-run=client -o yaml"
    • then we can run:
    • k run pod1 --image=nginx $do

• Setup VIM for yaml by adding these lines to the ~/.vimrc configuration file:

  • set et or set expandtab (spaces instead of tabs)
  • set si or ```set smartindent`` (automatic and smart indentation)
  • set ts=2 or set tabstop=2 (the number of spaces that a tab equates to)
  • set sts=2 or set softtabstop=2 (the number of spaces to use when expanding tabs)
  • set sw=2 or set shiftwidth=2 (the number of spaces to use when indenting or de-indenting a line)

  # .vimrc
  set et
  set si
  set ts=2
  set sts=2
  set sw=2
  

• Use kubectl shortnames:

  • no po ns deploy svc ing ds netpol pv pvc sa cm ep sc sts ...

• Use imperative commands whenever possible:
  • E.g. use: k run -h, k create deploy -h, k expose -h...
  • instead of: k apply -f <filename.yaml>

• Use kubectl explain to list the fields of supported API resources

• Use kubectl replace to replace an existing resource with some updated specs:
  • This saves you time compared to using k delete and k apply -f <filename>

• Use -w (i.e. --watch=true) to start watching updates to a particular object.
  • k get po -w to watch your pods

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