Troubleshoot CrashLoopBackOff Caused by a Missing TLS Secret
A deployment is failing because the application cannot load its TLS certificate. Create the missing secret and mount it into the deployment so the Flask app can serve TLS traffic.
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.
A deployment is failing because the application cannot load its TLS certificate. Create the missing secret and mount it into the deployment so the Flask app can serve TLS traffic.
A Pod must be fully isolated from the cluster network. Deny all incoming traffic and block all outgoing traffic except DNS queries on port 53.
A developer named siddhi requires read-only access to specific resources in the production namespace. Create a Role and RoleBinding to grant the minimum required permissions without any write access.
Enforce Kubernetes security best practices by disabling automatic ServiceAccount token mounting and providing a short-lived projected token to the application Pod.
Learn how to control traffic between Pods using Kubernetes NetworkPolicy. Apply a default deny-all policy and then selectively allow only the traffic that is required between frontend and backend Pods.
Learn how to taint a node, schedule a Pod using nodeSelector and tolerations, and share the host network, PID, and IPC namespaces with the Pod.
A multi-tier application runs across two namespaces. Learn how to isolate the application tier and restrict database access to only the application namespace.
Harden a container by implementing a read-only root filesystem with specific writable volumes for nginx. This is a critical security practice to prevent runtime modifications.