2.1 Error Handling

Objective

In this lab, you will deploy a deliberately broken NGINX deployment and use common Kubernetes CLI tools (kubectl) to investigate and identify the failure. This exercise is designed to improve your troubleshooting and diagnostic skills in real-world cluster environments. Don’t worry if you’re new to Kubernetes – we’ll walk you through everything step by step!

---

Part 1: Deploy a broken NGINX Application

Deploy nginx from file ~/exercise/kubernetes/Errors-and-DR/broken-nginx-1.yaml

Hint

Locally in the Code Server:

$ scp ~/exercise/kubernetes/Errors-and-DR/broken-nginx-1.yaml azuser@clusterX-<WorkshopID>-admin-0:/home/azuser/broken-nginx-1.yaml

On the remote machine:

$ kubectl apply -f broken-nginx-1.yaml

Part 2: Observe the Pod Status

Check the status of the pod.

Hint

$ kubectl get pods

Solution

You will likely see something like:

broken-nginx-1-XXXXX-XXXXX   0/1     ImagePullBackOff  .. ..

Part 3: Investigate the Failure

Describe the Pod to get detailed information.

Hint

$ kubectl describe pod broken-nginx-1-XXXXX-XXXXX

Look under the Events: section for failure reasons. What's the problem with this image?

Hint

Warning  Failed     12s (x2 over 24s)  kubelet            Failed to pull image "nginx:1.2S": rpc error: code = NotFound desc = failed to pull and unpack image "docker.io/library/nginx:1.2S": failed to resolve reference "docker.io/library/nginx:1.2S": docker.io/library/nginx:1.2S: not found

Part 4: Deploy one more broken NGINX Application

Deploy nginx from file ~/exercise/kubernetes/Errors-and-DR/broken-nginx-2.yaml.

Hint

Locally in the Code Server:

$ scp ~/exercise/kubernetes/Errors-and-DR/broken-nginx-2.yaml azuser@clusterX-<WorkshopID>-admin-0:/home/azuser/broken-nginx-2.yaml

On the remote machine:

$ kubectl apply -f broken-nginx-2.yaml

Part 5: Observe the Pod Status

Check the status of the pod.

Hint

$ kubectl get pods

You will likely see something like:

broken-nginx-1-XXXXX-XXXXX   0/1     CrashLoopBackOff  .. ..

Part 6: Investigate the Failure

1. Describe the Pod

Get detailed info about the pod.

Hint

$ kubectl describe pod broken-nginx-2-XXXXX-XXXXX

Look under the Events: section for failure reasons. What's the problem with this image?

HINT

Back-off restarting failed container or Error: exit code 1

2. Check the Container Logs

Inspect logs to find out why the container failed:

Hint

kubectl logs broken-nginx-2-XXXXX-XXXXX

Expected output:

nginx: [emerg] open() "/etc/nginx/nonexistent.conf" failed (2: No such file or directory)

Part 7: Fix the issue

Now create a corrected version of the deployment:

kubectl delete deployment broken-nginx

Update the deployment YAML with the correct command

Hint

Correct the args line (line number: 19)

args: ["nginx -g 'daemon off;'"]

Deploy the fixed version of the yaml file.

Hint

kubectl apply -f broken-nginx-2.yaml

Finally, test the deployment:

kubectl get pods
kubectl logs broken-nginx-2-XXXXX-XXXXX

End of Lab