vanshikamunjal665-containerization-theory.github.io

CONTAINERIZATION AND DEVOPS THEORY

25 MARCH 2026

CLASS TASK: RUN AND MANAGE A “HELLO WEB APP”

Reference Link:
https://upessocs.github.io/#dir=/Lectures/Containerization%20and%20DevOps/Theory/003%20Unit%203/&file=306%20Apache%20webserver%20deploy%20using%20kubernetis.md

📌 Objective

Deploy and manage a simple Apache-based web server using Kubernetes and perform the following tasks:

Screenshots of commands

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🧾 Step-wise Explanation of Commands

🔹 Step 1: Run a Pod

Command: kubectl run apache-pod --image=httpd

Explanation:
This command creates a Pod named apache-pod using the Apache (httpd) image.

🔹 Step 2: Verify Pod Status

Command: kubectl get pods

Explanation:
This command checks the status of the Pod. Initially, it shows ContainerCreating, and after some time it changes to Running.

🔹 Step 3: Access the Application

Command: kubectl port-forward pod/apache-pod 8081:80

Explanation:
This command forwards local port 8081 to container port 80, allowing access to the web application.

Open in Browser:
http://localhost:8081

Output:
The Apache default page (“It works!”) is displayed.

🔹 Step 4: Create Deployment

Command: kubectl create deployment apache --image=httpd

Explanation:
This command creates a Deployment named apache, which manages Pods and supports scaling.

🔹 Step 5: Verify Deployment

Command: kubectl get deployments
kubectl get pods

Explanation:
These commands verify that the Deployment is created and Pods are running.

🔹 Step 6: Scale the Application

Command: kubectl scale deployment apache --replicas=3

Explanation:
This command increases the number of Pods to 3, improving availability and load handling.

🔹 Step 7: Verify Scaling

Command: kubectl get pods

Explanation:
This confirms that multiple Pods (3 replicas) are running.

🔹 Step 8: Expose Deployment

Command: kubectl expose deployment apache --port=80 --type=NodePort

Explanation:
This exposes the Deployment as a Service, enabling external access.

🔹 Step 9: Break the Application (Debugging)

Command: kubectl set image deployment/apache httpd=wrongimage

Explanation:
This intentionally sets an incorrect image to simulate a failure scenario.

🔹 Step 10: Check Error

Command: kubectl get pods

Explanation:
Some Pods enter ErrImagePull or ImagePullBackOff, indicating failure to fetch the image.

🔹 Step 11: Diagnose the Issue

Command: kubectl describe pod <pod-name>

Explanation:
This shows detailed Pod information. The Events section reveals the image pull failure.

🔹 Step 12: Fix the Application

Command: kubectl set image deployment/apache httpd=httpd

Explanation:
This restores the correct image and resolves the issue.

🔹 Step 13: Final Verification

Command: kubectl get pods

Explanation:
All Pods return to the Running state, confirming successful recovery.

✅ Conclusion

The Apache web application was successfully deployed, accessed, scaled, debugged, and restored using Kubernetes.

🔥 Key Learnings