CKAD Practice Test 38 — 15 Questions

Question 1

During a canary deployment, you want to send 10% of traffic to the new version. You have two Deployments: 'app-stable' (version: stable) and 'app-canary' (version: canary). You use a Service with label selector 'app: myapp' and a second selector for version. How can you achieve the 10% traffic split?

Accepted Answer

Use an Ingress controller that supports canary deployments or a service mesh. Kubernetes Services do not support weighted load balancing natively. The common approach is to use an Ingress controller or service mesh. Option D is correct.

Answer

Use a Service with multiple ports

Answer

Set the Service's sessionAffinity to distribute load

Answer

Scale app-canary to 1 replica and app-stable to 9 replicas, and use a single Service that selects both

Question 2

You have a HorizontalPodAutoscaler (HPA) targeting a Deployment. The HPA is configured with 'targetCPUUtilizationPercentage: 50'. The current CPU utilization is 60% across the pods. What action does the HPA take?

Accepted Answer

Scale up the Deployment to reduce per-pod CPU utilization.. Option B is correct: HPA scales up to bring actual utilization closer to the target. Option A is incorrect because scaling down when above target would increase utilization further. Option C is incorrect because HPA does not wait for sustained load; it reacts based on the metric. Option D is incorrect because HPA does not stop itself; it continues to adjust.

Answer

Scale down the Deployment because the target is 50%.

Answer

Mark the HPA as unable to calculate metrics and stop scaling.

Answer

Take no action because the deviation is within tolerance.

Question 3

During a rolling update, you want to ensure that at most 2 pods are unavailable at any time. Which field should you set in the Deployment spec?

Accepted Answer

spec.strategy.rollingUpdate.maxUnavailable: 2. maxUnavailable defines the maximum number of pods that can be unavailable during a rolling update. Setting it to 2 ensures at most 2 pods are unavailable at any time.

Answer

spec.strategy.type: Recreate

Answer

spec.replicas: 2

Answer

spec.strategy.rollingUpdate.maxSurge: 2

Question 4

Which command scales a Deployment named 'web' to 5 replicas?

Accepted Answer

kubectl scale deployment web --replicas=5. The correct command is 'kubectl scale deployment web --replicas=5'.

Answer

kubectl set replicas deployment web 5

Answer

kubectl resize deployment web --replicas=5

Answer

kubectl autoscale deployment web --replicas=5

Question 5

You have an existing Deployment 'web' created with 'kubectl create deployment web --image=nginx --replicas=3'. You need to change the image to 'nginx:1.19' and record the change. Which command should you use?

Accepted Answer

kubectl set image deployment/web web=nginx:1.19 --record. Option B is correct: 'kubectl set image deployment/web web=nginx:1.19 --record' updates the image and records the command in the rollout history. Option A uses 'kubectl edit' which does not record changes by default unless '--record' is added. Option C uses 'kubectl replace' which requires a file. Option D applies a patch but '--record' is not a valid flag for patch.

Answer

kubectl replace -f deployment.yaml --record

Answer

kubectl edit deployment web --record

Answer

kubectl patch deployment web -p '{"spec":{"template":{"spec":{"containers":[{"name":"web","image":"nginx:1.19"}]}}}}' --record

Question 6

You have a Helm chart for an application. You want to upgrade the release but only if the upgrade does not introduce breaking changes. Which command should you use?

Accepted Answer

helm upgrade --dry-run my-release ./mychart. Helm does not have a dry-run for upgrades that guarantees no breaking changes, but 'helm upgrade --dry-run' simulates the upgrade and shows changes without applying them.

Answer

helm install --dry-run my-release ./mychart

Answer

helm rollback my-release 0

Answer

helm diff upgrade my-release ./mychart

Question 7

Which of the following is a valid method to perform a blue-green deployment in Kubernetes?

Accepted Answer

Create two Deployments and a Service, then change the Service's selector to point to the new version.. Blue-green deployment involves running two versions (blue and green) and switching traffic by updating the Service's selector.

Answer

Use kubectl rollout undo to switch between revisions.

Answer

Set spec.strategy.type: BlueGreen in the Deployment.

Answer

Use a DaemonSet to run both versions.

Question 8

Which TWO commands can be used to update the image of a Deployment? (Select two)

Accepted Answer

kubectl set image deployment/myapp app=nginx:1.21. kubectl set image and kubectl edit are valid ways to update a Deployment's image. Option A and D are correct.

Answer

kubectl update deployment myapp --image=nginx:1.21

Answer

kubectl replace deployment myapp --image=nginx:1.21

Question 9

You have created a HorizontalPodAutoscaler (HPA) named 'web-hpa' targeting a Deployment 'web'. The HPA uses targetCPUUtilizationPercentage: 80. The current CPU usage is 60%. How many replicas will the HPA set?

Accepted Answer

1. The HPA scales based on the ratio: desiredReplicas = ceil[currentReplicas * (currentMetricValue / targetMetricValue)]. With current replicas at 1, desired = ceil[1 * (60/80)] = ceil[0.75] = 1. So it remains at 1. Option A is correct.

Answer

The HPA would not be created if current usage is below target

Answer

2

Answer

0

Question 10

You need to perform a blue-green deployment using Deployments and Services. What is the most common approach to switch traffic from the old version (blue) to the new version (green)?

Accepted Answer

Change the Service's label selector to point to the green Deployment's pod labels. In a blue-green deployment, you have two Deployments (blue and green) and a Service that selects pods by a label. The Service's label selector initially matches the blue pods. To switch traffic to green, you update the Service's selector to match the green pods' labels. This instantly routes traffic to the green version.

Answer

Update the Deployment's image field in the blue Deployment to the new version

Answer

Delete the blue Deployment and create the green Deployment

Answer

Scale the blue Deployment to 0 and the green Deployment to desired replicas

Question 11

You want to update a Deployment's image from nginx:1.20 to nginx:1.21. Which command will perform a rolling update?

Accepted Answer

kubectl set image deployment/my-deployment nginx=nginx:1.21. The correct command to update a Deployment's image and trigger a rolling update is 'kubectl set image deployment/my-deployment nginx=nginx:1.21'.

Answer

kubectl create deployment my-deployment --image=nginx:1.21

Answer

kubectl apply -f deployment.yaml

Answer

kubectl edit deployment my-deployment

Question 12

Which kubectl command can be used to see the rollout status of a Deployment named 'web-app'?

Accepted Answer

kubectl rollout status deployment web-app. The correct command is 'kubectl rollout status deployment web-app'. This shows the status of the rollout.

Answer

kubectl rollout history deployment web-app

Answer

kubectl describe deployment web-app

Answer

kubectl status deployment web-app

Question 13

In a Deployment YAML, which field defines the number of pods to run?

Accepted Answer

spec.replicas. The 'replicas' field sets the desired number of pods. Option A is correct.

Answer

spec.strategy.replicas

Answer

spec.template.replicas

Answer

metadata.replicas

Question 14

You want to perform a rolling update of a Deployment. The Deployment has a maxSurge=1 and maxUnavailable=0. How many extra pods can be created above the desired count during the update?

Accepted Answer

1. maxSurge=1 means at most one additional pod can be created above the desired replicas.

Answer

Unlimited

Answer

0

Answer

Desired replicas

Question 15

You want to update a Deployment's image to a new version, ensuring that at most 2 pods are unavailable during the rollout. Which field in the Deployment spec should you set?

Accepted Answer

spec.strategy.rollingUpdate.maxUnavailable. The maxUnavailable field in the rolling update strategy specifies the maximum number of pods that can be unavailable during the update. Setting it to 2 ensures at most 2 pods are unavailable.

Answer

spec.replicas

Answer

spec.strategy.rollingUpdate.maxSurge

Answer

spec.minReadySeconds