CKA Workloads and Scheduling — Timed 10 Questions

Question 1

You need to update a Deployment's image from nginx:1.20 to nginx:1.21 using a rolling update strategy, but you want to ensure that during the update, at most 2 pods above the desired replicas (10) are running, and at least 8 pods are available at all times. Which strategy configuration should you apply?

10 minute time limit — choose an answer to begin.

Accepted Answer

maxSurge: 2, maxUnavailable: 2. To ensure that at most 2 pods above the desired replicas (10) are running, maxSurge must be set to 2. To ensure that at least 8 pods are available at all times, the maximum number of unavailable pods is 10 - 8 = 2, so maxUnavailable must be set to 2. Therefore, the correct configuration is maxSurge: 2, maxUnavailable: 2. Option D has been changed to an incorrect option to ensure there is only one correct answer.

Answer

maxSurge: 3, maxUnavailable: 2

Answer

maxSurge: 3, maxUnavailable: 3

Answer

maxSurge: '20%', maxUnavailable: '20%'

Question 2

You have a DaemonSet that is supposed to run on all nodes, but you notice it is not running on a node with a taint 'dedicated=monitoring:NoSchedule'. What must be added to the DaemonSet's pod template to make it run on that node?

Accepted Answer

A toleration with key 'dedicated', value 'monitoring', effect 'NoSchedule'. A DaemonSet's pods must tolerate a node's taints to be scheduled on that node. The taint 'dedicated=monitoring:NoSchedule' means pods without a matching toleration will not be scheduled. Adding a toleration with key 'dedicated', value 'monitoring', and effect 'NoSchedule' explicitly allows the DaemonSet pod to bypass this taint and run on the node.

Answer

Add the annotation 'scheduler.alpha.kubernetes.io/tolerations'

Answer

A nodeSelector with key 'dedicated' and value 'monitoring'

Answer

Set the priorityClassName to 'system-node-critical'

Question 3

You have a CronJob that runs a batch job every 5 minutes. The job takes about 2 minutes to complete. However, if a job takes longer than 5 minutes, you want to prevent a new job from starting until the previous one finishes. Which CronJob field should you configure?

Accepted Answer

concurrencyPolicy: Forbid. The `concurrencyPolicy` field in a CronJob spec controls how the controller handles overlapping job executions. Setting it to `Forbid` ensures that if a previous job is still running when the next scheduled time arrives, the new job is skipped, preventing concurrent runs. This directly addresses the requirement to block a new job from starting until the previous one finishes.

Answer

successfulJobsHistoryLimit

Answer

suspend: true

Answer

startingDeadlineSeconds

Question 4

Which of the following describes the role of init containers in a pod?

Accepted Answer

They run to completion before any main containers start, and each init container must complete successfully before the next one starts. Init containers are specialized containers that run before the main application containers in a Pod. They are defined in the Pod spec under `initContainers` and execute sequentially: each init container must complete successfully (exit code 0) before the next one starts. Only after all init containers have finished does Kubernetes start the main containers defined in the `containers` array. This ensures prerequisite setup tasks (e.g., waiting for a database, running migrations) are completed before the application starts.

Answer

They run in parallel with the main containers to provide additional services

Answer

They are used for liveness and readiness probes of the main container

Answer

They run after the main containers have started to clean up resources

Question 5

You need to schedule a pod to a specific node named 'worker-2' for testing purposes. Which field should you set in the pod spec?

Accepted Answer

nodeName. The `nodeName` field in the PodSpec directly assigns the pod to a specific node by name, bypassing the scheduler entirely. Setting `nodeName: worker-2` forces the kubelet on that node to run the pod, making it the correct choice for pinning a pod to a specific node for testing.

Answer

schedulerName

Answer

affinity

Answer

nodeSelector

Question 6

Which command creates a ConfigMap named 'app-config' from a file 'config.properties'?

Accepted Answer

kubectl create configmap app-config --from-file=config.properties. `kubectl create configmap app-config --from-file=config.properties` directly reads the file `config.properties` and creates a ConfigMap named `app-config` with a key equal to the filename (i.e., `config.properties`) and the value set to the file's content. The `--from-file` flag without a key specification uses the filename as the key. Option A is incorrect because the syntax `--from-file=key=config.properties` creates a ConfigMap with the key "key", not the filename. Option C is incorrect because `--from-literal` is for literal key-value pairs, not files. Option D is incorrect because `kubectl create secret generic` creates a Secret, not a ConfigMap.

Answer

kubectl create configmap app-config --from-file=key=config.properties

Answer

kubectl create configmap app-config --from-literal=config.properties

Answer

kubectl create secret generic app-config --from-file=config.properties

Question 7

You want to mount a Secret named 'db-secret' as a volume in a pod. Which volume type should you use in the pod spec?

Accepted Answer

secret. Kubernetes provides a dedicated 'secret' volume type specifically designed to mount Secret objects (like 'db-secret') as files into a pod. This volume type automatically handles decryption and projection of the secret data into the container's filesystem, ensuring sensitive information is securely exposed without being stored in the pod definition or environment variables.

Answer

hostPath

Answer

configMap

Answer

emptyDir

Question 8

Which TWO of the following are valid strategies for a Deployment's rolling update? (Select TWO.)

Accepted Answer

maxUnavailable: 0. Setting `maxUnavailable: 0` ensures that during a rolling update, no Pods are taken down below the desired replica count, guaranteeing zero downtime. This is a valid strategy when you want to maintain full availability at the cost of potentially slower updates, as new Pods must be created before any old ones are terminated.

Answer

podManagementPolicy: OrderedReady

Answer

scaleUp: 2

Answer

type: Recreate

Question 9

A Deployment named 'web-app' is configured with rolling update strategy. You run 'kubectl describe deployment web-app' and see 'RollingUpdateStrategy: 25% max unavailable, 25% max surge'. You have 4 replicas. You update the image. How many pods will be unavailable during the rollout at most?

Accepted Answer

1. With a rolling update strategy of 25% max unavailable and 25% max surge on a Deployment with 4 replicas, the maximum number of pods that can be unavailable during the rollout is 1. This is because 25% of 4 replicas equals 1, and Kubernetes rounds down for max unavailable, ensuring at least 3 pods remain available throughout the update.

Answer

0

Answer

4

Answer

2

Question 10

Which kubectl command creates a ConfigMap named 'app-config' from a file 'config.properties'?

Accepted Answer

kubectl create configmap app-config --from-file=config.properties. `kubectl create configmap app-config --from-file=config.properties` creates a ConfigMap named 'app-config' using the contents of the file 'config.properties'. The `--from-file` flag reads the file as-is and stores its content under a key that defaults to the filename (config.properties). This is the standard method for creating a ConfigMap from a single file.

Answer

kubectl apply configmap app-config config.properties

Answer

kubectl create configmap app-config --from-literal=config.properties

Answer

kubectl create configmap app-config --from-env-file=config.properties