Focused, hands-on problems for sharpening your DevOps and server-side skills. Some teach specific concepts while others mirror real-world scenarios. Every challenge includes hints, feedback, and automated solution checks.
Challenges contributed by the community members sharing their knowledge and expertise.
node-02 is back from a kernel upgrade but still shows Ready,SchedulingDisabled, and the Pods that can only run on it are stuck in Pending. Bring the node back into service and get the workload running, without touching the workload itself.
A storefront needs eight replicas, and the platform team wants them split down the middle between the two availability zones. An uneven split must be refused by the scheduler rather than quietly tolerated.
The security team left five NetworkPolicy files on the workstation. Only one of them lets the frontend reach the backend while granting nothing more. Identify it and deploy it, unchanged.
A worker node dropped to NotReady and part of the workload went with it. The container runtime is fine and the control plane is healthy; the trail leads from kubectl symptoms down into systemd and the kubelet configuration. Diagnose the node and bring it back.
A Snake game Deployment and ClusterIP Service are already running in the snake namespace. Create a Traefik Ingress that serves the game over HTTPS using an existing cert-manager-issued TLS Secret.
A Deployment running a distroless Chainguard nginx image (cgr.dev/chainguard/nginx) is deployed in the namespace webapps, fronted by a ClusterIP Service. Port-forward that Service to localhost port 3333 on cplane-01, use curl to save the response body to /home/laborant/index.html, and verify the file is accessible and contains the expected content.
A Job manifest at /home/laborant/batch-job.yaml is exiting with a non-zero exit status. The Job has limited retries configured. Inspect the cluster and the manifest to find the bug, fix it, and reapply.
Create a multi-container Pod with different user IDs per container while sharing a common group ID at the Pod level for collaborative file access.
Use kubectl proxy to open a local, already authenticated HTTP endpoint to the Kubernetes API server, then use curl to list every Secret in the gliese-581 namespace and save the raw JSON response to /home/laborant/secret-list.json.
Update a production NGINX ConfigMap to restrict TLS to v1.3 only, then verify the change enforces the security policy.
