Hands-On Practice Set 1

Let's think about it this way for a moment

This round is about putting the Basic/Intermediate concepts you've already learned into practice — there's nothing new to teach here. It's all hands-on: telling Pod, Deployment, and Service apart, spotting errors in YAML, and writing correct kubectl commands. Each task shouldn't take more than 5 minutes.

Let's connect this to a real scenario

Task 1: Explain, in one sentence each, what Pod, Deployment, and Service are each responsible for. Task 2: If a Deployment YAML has `selector.matchLabels: app: web` but `template.metadata.labels` is mistakenly set to `app: website`, predict and write down what error you'd get. Task 3: Write down when you'd use each of the three Service types (ClusterIP, NodePort, LoadBalancer), with examples. Task 4: If running `kubectl get pods` shows a pod stuck in 'Pending' status, write down two commands you'd use to debug it.

• Can explain the differences between Pod/Deployment/Service
• Can track down a label-mismatch error in a Deployment YAML
• Have written down two commands for debugging a Pod stuck in Pending

Let's look at it together

# Task 2 - label mismatch
selector.matchLabels: { app: web }
template.metadata.labels: { app: website }   # MISMATCH!

Result: Deployment creates pods with label "app: website",
but its own selector looks for "app: web" — it will never
see its own pods as "managed", and may create pods endlessly
or error depending on the Kubernetes version.

# Task 4 - debug a Pending pod
kubectl describe pod <pod-name>   # check Events for the reason
kubectl get nodes                  # check if any node has capacity

You'll come away knowing the differences between Pod/Deployment/Service, how to track down a label-mismatch bug, and the commands for debugging a Pending pod.