Chapter 19 CKA Exam Drilling
The CKA tests speed, not knowledge: two hours, 15-20 tasks on live clusters. The exam environment and its rules, the speed kit, triage and time budgeting, the mistakes that cost points, then timed randomized tasks across all five domains and three mock exams graded like the real one.
In plain words
Imagine you already know how to cook every dish on a menu. Now you enter a cooking competition: 17 dishes in two hours, in a kitchen you've never seen, with a judge who only tastes the final plate. Knowing the recipes isn't enough; you need to know where the knives are, which dishes to cook first, when to give up on a soufflé that won't rise, and to check every plate before it goes out. Chefs who know less but practised under the clock often beat chefs who know more.
That's the CKA. Chapters 15 to 18 were the recipes. This chapter is the competition training: the speed kit (alias k, $do, generators), time management (budgets, three passes, partial credit), the classic mistakes (wrong context, wrong namespace, not verifying), the docs you're allowed to use, and drills that repeat each task shape until it's fast.
Why it matters on call
The CKA is the certification platform and SRE job ads ask for most, and it's a milestone in your plan. It isn't a knowledge test: it's graded on final cluster state, task by task, under a tight clock, and people who know Kubernetes well fail it on time and on context mistakes. This chapter is about converting what you already know into points.
The habits outlast the exam. "Switch to the right cluster and namespace before touching anything" is the same discipline that prevents a production change landing in the wrong environment. Generating YAML instead of writing it, verifying every change with a concrete check, and moving on when stuck instead of sinking 25 minutes are exactly how good on-call engineers work. And the wrong-answer log is a small version of how teams learn from incidents.
Lessons
- The exam: what it is and what it is not
- The five domains and the tasks they turn into
- The speed kit: alias, $do, generators, editors, explain
- Time: budgets, triage, skipping, partial credit
- How points are lost: the classic mistakes
- Using the docs at exam speed
- The wrong-answer log, and how the app repeats your misses
- The last two weeks and exam day
38 hands-on labs (missions, incidents and drills) run in the terminal: Open this chapter in the terminal Free, in your browser - a real Ubuntu terminal to try it in, with missions that check your work.
Questions people ask
Is the CKA multiple choice?
No. It's 15 to 20 performance-based tasks on real clusters, command line only, in two hours. Each task asks for a cluster state or a file ("create this", "fix that", "write the result to /opt/course/..."), and a script checks the end state afterwards. How you got there doesn't matter; only what you leave behind is graded.
Can I use documentation during the exam?
Yes, but only kubernetes.io/docs, kubernetes.io/blog, helm.sh/docs and, for the CKA, gateway-api.sigs.k8s.io, in the exam's own browser. You can use the docs search but not follow results to other sites. No notes, no other tabs. So the skill is knowing which page holds the example you need, and kubectl explain is often faster.
How is this different from what I learned in chapters 15 to 18?
It adds almost no new Kubernetes. It's the same tasks under exam conditions: short, timed, each preceded by a context switch, graded only on end state. The drills randomise names, namespaces and faults so you can't memorise answers, and they measure whether you're fast enough, not just correct.
Is killer.sh harder than the real exam?
Deliberately, yes. The two included killer.sh sessions are harder and longer than the exam, so a score that would fail the real thing is common among people who then pass comfortably. Use it for calibration: look at which tasks you missed and why, redo the session untimed while it's open, and log the misses.
What score do I need, and what if I fail?
66%, not curved. Results usually arrive by email within 24 hours, with domain percentages. The exam fee includes one free retake within 12 months, so a fail is expensive in time, not money. Put the weakest domain at the top of your log and book the retake a week or two out, not the next day.