Hands-on Lab·Certified Kubernetes Security Specialist
Common CKS Task Mistakes
On a performance exam nothing tells you that you were wrong. Every one of these five produced a success message on a real cluster and left the task unfinished, which is the only failure mode that matters when there is no answer sheet.
Working at Exam Speed Guide 39 of 40 Intermediate
- Kubernetesapiserver v1.36.4, kubelet v1.36.3
- Runtimecontainerd 2.2.6
- CNICilium 1.18.1
- Built withkubeadm v1.36.3
- TimeAbout 15 min
All five were run on a live cluster. The messages, the warnings and the refusals are the apiserver's own.
- Host kernel7.0.0-29
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| CKA6001 | 192.168.0.46 | Ubuntu 26.04 LTS | Control Plane Node (tainted NoSchedule) | 2 Core | 4 GB | 50 GB |
| CKA6001-NODE01 | 192.168.0.47 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
| CKA6001-NODE02 | 192.168.0.48 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
This guide includes
Use this shortly before the exam. This matters because on a performance exam nothing tells you that you were wrong - a task can look finished and score nothing, and each of these is one word or one label away from correct.
- using a restricted label that warns and stops absolutely nothing
- enforcing afterwards on a namespace that is already violating, the other half of the same trap
- running a dry run that agrees with you, then checking the same manifest a second way
- asking a permission question about the wrong identity
- creating exactly the right object in the wrong place
Before you start
- guide 18 - two of the five are about that admission controller.
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The label that warns and stops nothing
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Enforcing it afterwards, which is the other half of the same trap
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The dry run that agrees with you
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Two more, and both are one word