24 - Certification Exam Prep (CKA/CKAD/CKS)

Why this matters

Certification forces structured, timed, hands-on practice — no multiple choice, all real kubectl/YAML under a clock. Even if you never need the cert for a job, prepping for it is one of the fastest ways to close remaining gaps.

Read this first — Definitions & Explanations

CKA (Certified Kubernetes Administrator)

Focus: cluster operations — scheduling, networking, security basics, maintenance, troubleshooting under time pressure.

CKAD (Certified Kubernetes Application Developer)

Focus: building/deploying apps on Kubernetes — workloads, config, multi-container Pods, services, observability basics.

CKS (Certified Kubernetes Security Specialist)

Focus: hardening clusters and workloads — supply chain, runtime security, network policies, auditing, least privilege.

Exam reality

Speed comes from muscle memory + knowing how to use docs quickly — not from memorizing every YAML field once.

Prep loop that works

1. Finish this path module-by-module with labs
2. Redo weak topics
3. Timed mock scenarios
4. Review mistakes the same day

Recommended order

1. CKA (Certified Kubernetes Administrator) — cluster admin, troubleshooting, covers most of Phases 1-2 of this path
2. CKAD (Certified Kubernetes Application Developer) — faster to get after CKA, overlaps heavily, app-focused
3. CKS (Certified Kubernetes Security Specialist) — requires an active CKA first, covers Phase 3 of this path

Official docs (read for detail)

• CKA Curriculum
• Kubernetes Documentation (home)
• kubectl Cheat Sheet
• API Overview
• Training & Certification (CNCF)

Key Concepts / Exam Mechanics

• Open-book: you get the official Kubernetes docs during the exam — practice navigating them FAST
• Time pressure is the real challenge, not the concepts — CKA is 2 hours, ~15-20 tasks across multiple clusters (via kubectl config use-context)
• kubectl shortcuts are essential: aliases, --dry-run=client -o yaml, imperative commands to generate YAML fast
• Practice environment: killer.sh (comes free with exam registration, 2 sessions) — closest thing to the real exam, harder than the actual test on purpose

YouTube search terms

• "CKA exam tips and tricks 2025/2026"
• "CKA exam simulator killer.sh walkthrough"
• "kubectl productivity tips for CKA exam"
• "CKS exam tips Kubernetes security certification"

Exam-day productivity setup (practice this now, not on exam day)

# Put this in your shell profile and drill until it's muscle memory
alias k=kubectl
export do="--dry-run=client -o yaml"     # k run nginx --image=nginx $do > pod.yaml
export now="--force --grace-period=0"    # k delete pod x $now
complete -o default -F __start_kubectl k

# Speed-generate YAML instead of writing from scratch
kubectl create deployment web --image=nginx --replicas=3 $do > deploy.yaml
kubectl expose deployment web --port=80 $do > svc.yaml
kubectl create job myjob --image=busybox $do -- echo hi > job.yaml

# Fast context switching (exam gives you multiple clusters)
kubectl config get-contexts
kubectl config use-context <name>

# vim setup for YAML editing (set this in exam terminal at the start)
# ~/.vimrc equivalent commands to run at exam start:
#   set expandtab
#   set shiftwidth=2
#   set tabstop=2

Hands-on lab (on prod-sim)

• Do timed drills: pick 5 random topics from Phases 1-2, give yourself 90 seconds each to solve blind (no notes) using only kubectl + --help + imperative generators
• Practice the etcd backup/restore (topic 14) until you can do it in under 5 minutes
• Practice RBAC troubleshooting (topic 08) — "why can't this ServiceAccount do X" — blind
• Time yourself doing a full node drain+cordon+uncordon+taint cycle (topic 06/11)

Notes

(fill in your own words — track your mock exam scores here over time)