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.
Learn how to configure a Kubernetes CronJob to automatically take etcd snapshot backups every 6 hours — a critical skill for cluster disaster recovery and operational health.
Learn how to reconfigure the Kubernetes cluster DNS domain by updating CoreDNS ConfigMap and kubelet configuration on all nodes, a critical skill for custom cluster networking and CKA exam preparation.
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.
A helper script that lists every container image running in the cluster — along with its on-disk size and the workload that uses it — has been downloaded to cplane-01. Install it as a kubectl plugin named kubectl-images so that kubectl images works from any directory.
Create a Pod that uses a generic ephemeral volume backed by a dynamic StorageClass. Unlike emptyDir, ephemeral volumes are provisioned as PersistentVolumeClaims and support storage requests and access modes.
Add the official Argo CD Helm repository, then use helm template to render the Argo CD chart for a dedicated namespace while skipping the chart's bundled CRDs, since they are already installed in the cluster.
Configure a Vertical Pod Autoscaler (VPA) with a per-container resource policy that provides recommendations for the main container while excluding the sidecar container from any VPA-managed scaling.
A webapp deployment in the prod namespace is stuck in CrashLoopBackOff. The application's startup probe checks that its existing config directory is intact before the container is marked healthy. Fix the deployment so configuration is injected correctly and the pod reaches Running state with its health check endpoint responding on port 8080.
A MariaDB deployment and its PVC were accidentally deleted. The PersistentVolume survived due to its Retain policy. Restore the database by rebinding the existing PV without losing any data.