Kubernetes basics review in Microservices - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Kubernetes Pod Status Check

What is the output of the command kubectl get pods immediately after creating a Pod with an invalid image name?

Microservices

kubectl run invalid-pod --image=nonexistentimage12345 --restart=Never
kubectl get pods

A

NAME          READY   STATUS             RESTARTS   AGE
invalid-pod   0/1     ImagePullBackOff   0          10s

B

NAME          READY   STATUS    RESTARTS   AGE
invalid-pod   1/1     Running   0          10s

C Error from server (NotFound): pods "invalid-pod" not found

D

NAME          READY   STATUS    RESTARTS   AGE
invalid-pod   0/1     Completed 0          10s

💡 Hint

Think about what happens when Kubernetes cannot pull the container image.

When Kubernetes tries to start a Pod with a non-existent image, it fails to pull the image and the Pod status becomes 'ImagePullBackOff'.

🧠 Conceptual

intermediate

Kubernetes Service Types

Which Kubernetes Service type exposes the service on a cluster-internal IP only, making it reachable only within the cluster?

A ExternalName

B LoadBalancer

C NodePort

D ClusterIP

💡 Hint

Think about which service type does not expose ports outside the cluster.

ClusterIP service type exposes the service on an internal IP accessible only within the cluster.

❓ Troubleshoot

advanced

Debugging Kubernetes Deployment Rollout Failure

You deployed a new version of your app using a Deployment, but the rollout is stuck and pods are not becoming ready. Which kubectl command helps you see detailed rollout status and errors?

A kubectl describe deployment <deployment-name>

B kubectl rollout status deployment/<deployment-name>

C kubectl logs deployment/<deployment-name>

D kubectl get pods --watch

💡 Hint

Look for a command that specifically tracks rollout progress.

The command 'kubectl rollout status' shows the progress and any issues during a deployment rollout.

🔀 Workflow

advanced

Kubernetes ConfigMap Usage

You want to update a ConfigMap used by a running Pod without restarting the Pod. Which approach allows the Pod to see the updated ConfigMap data automatically?

A Mount the ConfigMap as a volume inside the Pod

B Pass ConfigMap data as environment variables to the Pod

C Use kubectl exec to manually update files inside the Pod

D Delete and recreate the Pod after updating the ConfigMap

💡 Hint

Think about how Kubernetes handles ConfigMap volumes and environment variables.

ConfigMaps mounted as volumes are updated automatically inside the Pod, while environment variables require Pod restart.

✅ Best Practice

expert

Kubernetes Resource Limits and Requests

What is the main reason to set both resource requests and limits for containers in a Kubernetes Pod?

A To guarantee the container gets exactly the requested resources at all times

B To ensure the container never uses more CPU or memory than requested

C To allow Kubernetes scheduler to place Pods efficiently and prevent resource overuse

D To automatically restart the Pod if it exceeds resource usage

💡 Hint

Consider how Kubernetes uses requests and limits differently for scheduling and runtime.

Requests help the scheduler decide where to place Pods, while limits prevent containers from using excessive resources at runtime.