Pod definition in YAML in Kubernetes - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

Output of a simple Pod creation command

What is the output when you run kubectl apply -f pod.yaml with the following Pod definition?

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: test-pod
spec:
  containers:
  - name: nginx
    image: nginx:latest

A pod/test-pod created

B pod/test-pod configured

C error: unable to recognize "pod.yaml": no matches for kind "Pod" in version "v1"

D error: unable to read file: pod.yaml not found

💡 Hint

Check the output message after applying a valid Pod YAML file.

When you apply a valid Pod YAML file for the first time, kubectl outputs 'pod/ created'.

🧠 Conceptual

intermediate

Understanding Pod restart policy

Given this Pod YAML snippet, what is the effect of the restartPolicy: Never setting?

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: example-pod
spec:
  restartPolicy: Never
  containers:
  - name: busybox
    image: busybox
    command: ['sleep', '3600']

A The Pod will restart the container only on failure exit codes.

B The Pod will never restart the container if it exits or crashes.

C The Pod will restart the container only if manually triggered.

D The Pod will always restart the container regardless of exit status.

💡 Hint

Think about what 'Never' means for restart behavior.

The restartPolicy 'Never' means the container will not be restarted automatically if it stops or crashes.

❓ Configuration

advanced

Correct YAML for multiple containers in a Pod

Which YAML snippet correctly defines a Pod with two containers named app and sidecar?

A

apiVersion: v1
kind: Pod
metadata:
  name: multi-container-pod
spec:
  containers:
  - name: app
    image: app-image
  - name: sidecar
    image: sidecar-image

B

apiVersion: v1
kind: Pod
metadata:
  name: multi-container-pod
spec:
  container:
  - name: app
    image: app-image
  - name: sidecar
    image: sidecar-image

C

apiVersion: v1
kind: Pod
metadata:
  name: multi-container-pod
spec:
  containers:
    name: app
    image: app-image
    name: sidecar
    image: sidecar-image

D

apiVersion: v1
kind: Pod
metadata:
  name: multi-container-pod
spec:
  containers:
  - app
    image: app-image
  - sidecar
    image: sidecar-image

💡 Hint

Check the key name for the list of containers and the indentation.

The key must be 'containers' (plural) with a list of container objects each having 'name' and 'image'.

❓ Troubleshoot

advanced

Diagnosing Pod creation failure due to missing fields

You try to create a Pod with this YAML but get an error. What is the most likely cause?

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: incomplete-pod
spec:
  containers:
  - image: nginx

A Missing kind field causes the error.

B Missing apiVersion causes the error.

C Missing container name under containers list causes validation error.

D Missing metadata name causes the error.

💡 Hint

Check the required fields inside each container definition.

Each container must have a 'name' field; missing it causes Pod creation to fail.

✅ Best Practice

expert

Best practice for labeling Pods in YAML

Which YAML snippet follows best practices for labeling a Pod to enable easy selection and management?

A

apiVersion: v1
kind: Pod
metadata:
  name: labeled-pod
  labels:
    app: myapp
spec:
  containers:
  - name: app
    image: myapp-image

B

apiVersion: v1
kind: Pod
metadata:
  name: labeled-pod
  labels:
    myapp: app
    prod: true
spec:
  containers:
  - name: app
    image: myapp-image

C

apiVersion: v1
kind: Pod
metadata:
  name: labeled-pod
spec:
  labels:
    app: myapp
    environment: production
  containers:
  - name: app
    image: myapp-image

D

apiVersion: v1
kind: Pod
metadata:
  name: labeled-pod
  labels:
    app: myapp
    environment: production
spec:
  containers:
  - name: app
    image: myapp-image

💡 Hint

Labels should be under metadata and use clear key names.

Labels belong under metadata.labels and should be descriptive for easy selection.