Quiz Time: Running Apps

Here are six more questions, this time about running apps for real. Configuration, storage, health, limits, security, and scheduling. Same rules as before. Listen, pause, think, and then check your answer.

• Six more questions
• Production topics
• Think before the answer

Config

Question 1. Which object should hold a database password? A, A ConfigMap. B, A Secret. C, A Label. D, An Annotation. Pause the video, and think. The answer is B. Secrets are for sensitive values, with their own access rules.

Storage

Question 2. What lets data survive when a pod is replaced? A, An emptyDir volume. B, A persistent volume claim. C, A container layer. D, A label. Pause the video, and think. The answer is B. A claim binds to a persistent volume, which outlives the pod.

Probes

Question 3. What happens when a readiness probe fails? A, The container is restarted. B, The pod is removed from the service. C, The node is drained. D, The image is pulled again. Pause the video, and think. The answer is B. A pod that is not ready receives no traffic, but keeps running.

Limits

Question 4. What happens when a container exceeds its memory limit? A, It is slowed down. B, It is killed, O O M killed. C, Nothing. D, It moves to another node. Pause the video, and think. The answer is B. Memory cannot be throttled, so the kernel kills the container.

RBAC

Question 5. What does a role binding do? A, Creates a pod. B, Gives a role to users or service accounts. C, Encrypts secrets. D, Schedules pods. Pause the video, and think. The answer is B. A role lists permissions, and the binding says who receives them.

Scheduling

Question 6. Which feature keeps pods away from a node, unless they have permission? A, Labels. B, Taints and tolerations. C, Probes. D, Quotas. Pause the video, and think. The answer is B. A taint repels pods, and a toleration is the pod's permission to enter.

Summary