Udemy CKA 강의 정리 121: Practice Test - OS Upgrade

해당 내용은 Udemy의 Certified Kubernetes Administrator (CKA) with Practice Tests 강의를 공부한 내용입니다. 내용을 그대로 번역하기보다는, 제가 이해하기 쉬운 대로 수정한 부분들이 있습니다.

⚠️ 영어 독해가 많이 부족합니다. 틀린 내용이 있으면 알려주시면 감사하겠습니다.

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Q1. Let us explore the environment first. How many nodes do you see in the cluster?

 

Q2. How many applications do you see hosted on the cluster?

Check the number of deployments in the default namespace.

 

Q3. Which nodes are the applications hosted on?

 

Q4. We need to take node01 out for maintenance. Empty the node of all applications and mark it unschedulable.

 

Q5. What nodes are the apps on now?

 

Q6. The maintenance tasks have been completed. Configure the node node01 to be schedulable again.

 

Q7. How many pods are scheduled on node01 now?

 

Q8. Why are there no pods on node01?

 

Q9. Why are the pods placed on the controlplane node?

 

Q10. Time travelling to the next maintenance window…

 

Q11. We need to carry out a maintenance activity on node01 again. Try draining the node again using the same command as before: kubectl drain node01 --ignore-daemonsets Did that work?

 

Q12. Why did the drain command fail on node01? It worked the first time!

 

Q13. What is the name of the POD hosted on node01 that is not part of a replicaset?

 

Q14. What would happen to hr-app if node01 is drained forcefully?

 

Q15. Oops! We did not want to do that! hr-app is a critical application that should not be destroyed. We have now reverted back to the previous state and re-deployed hr-app as a deployment.

 

Q16. hr-app is a critical app and we do not want it to be removed and we do not want to schedule any more pods on node01. Mark node01 as unschedulable so that no new pods are scheduled on this node. Make sure that hr-app is not affected.