Certified Kubernetes Associate (CKA) Study Notes

This is my study guide for the Certified Kubernetes Associate (CKA) exam.
https://www.cncf.io/certification/cka/

2Hrs | Cost $375 | Online Exam
K8s version 1.22 (Oct 13, 2021)

CKA Curriculum

Updated exam curriculum for v1.22
https://github.com/cncf/curriculum/

Domain	Weight
1. Cluster Architecture, Installation & Configuration	25%
1.1. Manage role based access control (RBAC)
1.2. Use Kubeadm to install a basic cluster
1.3. Manage a highly-available Kubernetes cluster
1.4. Provision underlying infrastructure to deploy a Kubernetes cluster
1.5. Perform a version upgrade on a Kubernetes cluster using Kubeadm
1.6. Implement etcd backup and restore
2. Workloads & Scheduling	15%
2.1. Understand deployments and how to perform rolling update and rollbacks
2.2. Use ConfigMaps and Secrets to configure applications
2.3. Know how to scale applications
2.4. Understand the primitives used to create robust, self-healing, application deployments
2.5. Understand how resource limits can affect Pod scheduling
2.6. Awareness of manifest management and common templating tools
3. Services & Networking	20%
3.1. Understand host networking configuration on the cluster nodes
3.2. Understand connectivity between Pods
3.3. Understand ClusterIP, NodePort, LoadBalancer service types and endpoints
3.4. Know how to use Ingress controllers and Ingress resources
3.5. Know how to configure and use CoreDNS
3.6. Choose an appropriate container network interface plugin
4. Storage	10%
4.1. Understand storage classes, persistent volumes
4.2. Understand volume mode, access modes and reclaim policies for volumes
4.3. Understand persistent volume claims primitive
4.4 Know how to configure applications with persistent storage
5. Troubleshooting	30%
5.1. Evaluate cluster and node logging
5.2. Understand how to monitor applications
5.3. Manage container stdout & stderr logs
5.4. Troubleshoot application failure
5.5. Troubleshoot cluster component failure
5.6 Troubleshoot networking

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 v1.22
  https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.22/

CKA Training

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

CKA Lab Exercises

My CKA Lab Exercises

https://github.com/tplisson/k8s-CKA-study-guide/blob/main/CKA-Lab-Exercises.md

Other CKA Lab Exercises

• killer.sh_ https://killer.sh/cka

  • not free but worth it
  • 29.99€ for 2 CKA sessions of the same mock exam

• Chad M. Crowell
  https://github.com/chadmcrowell/CKA-Exercises

• Ashutosh
  https://github.com/ashutoshvct/k8s/tree/master/cka-exam

• David-VTUK
  https://github.com/David-VTUK/CKA-StudyGuide/

• stretchcloud
  https://github.com/stretchcloud/cka-lab-practice

CKA 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 ...

• 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