Executing commands in Pods in Kubernetes - Mini Project: Build & Apply

Executing Commands in Kubernetes Pods

📖 Scenario: You are managing a Kubernetes cluster. Sometimes you need to run commands inside a running Pod to check its status or debug issues.

🎯 Goal: Learn how to execute commands inside a Kubernetes Pod using kubectl exec.

📋 What You'll Learn

Create a Pod manifest with a specific name and image

Add a label to the Pod for easy selection

Use kubectl exec to run a command inside the Pod

Display the output of the command executed inside the Pod

💡 Why This Matters

🌍 Real World

Running commands inside Pods helps troubleshoot and inspect running applications without needing to redeploy or restart them.

💼 Career

Kubernetes administrators and DevOps engineers often use <code>kubectl exec</code> to debug issues and verify application states inside containers.

1

Create a Pod manifest

Create a YAML file named mypod.yaml that defines a Pod with the name mypod using the image busybox. The Pod should run the command sleep 3600 to keep it alive.

Kubernetes

# Create a YAML manifest for the Pod named mypod
# Your code here

Need a hint?

Use apiVersion: v1, kind: Pod, and specify metadata.name as mypod. Under spec.containers, set the container name, image, and command.

2

Add a label to the Pod

Add a label app: testpod under metadata.labels in the mypod.yaml file.

Kubernetes

apiVersion: v1
kind: Pod
metadata:
  name: mypod
  # Add labels here
  labels:
    app: testpod
spec:
  containers:
  - name: busybox-container
    image: busybox
    command: ["sleep", "3600"]
# Your code here

Need a hint?

Under metadata, add a labels section with app: testpod.

3

Execute a command inside the Pod

Use the command kubectl exec mypod -- ls / to list the root directory inside the Pod.

Kubernetes

# Run the command to list root directory inside the Pod
# Your code here

Need a hint?

Use kubectl exec followed by the Pod name mypod, then -- and the command ls /.

4

Display the output of the command

Run the command kubectl exec mypod -- ls / in your terminal and write the output exactly as it appears.

Kubernetes

# Paste the output of the command here
# Your output here

Need a hint?

Run the command in your terminal and copy the exact output listing the root directories inside the Pod.