Challenge on ,
Edit a File in a Running Kubernetes Pod: a Distroless Container Case
Learn how to edit a file in a distroless container that runs as a non-root user in a Kubernetes namespace that enforces the baseline Pod Security Standard.
Challenges
Focused, hands-on DevOps and server-side problems with hints, feedback, and automated solution checks.
Challenge on , ,
Intercept and Analyze Encrypted Traffic of a Suspicious Container
Play a security researcher: identify the hosts a black-box container keeps making encrypted HTTPS calls to, route them through a MITM proxy, fake the certificate, and see what the container sends over the network.
Challenge on ,
Debug a Go Container Image That Fails to Start After a Recent Change
A Go service that has always been shipped as a static binary in a scratch-y image suddenly fails to start in a container, while the local build works as before. Find what recent changes caused it and fix the image without reverting them.
Challenge on
Purge an Accidentally Pushed Image From a Container Registry
Sometimes an image needs to be removed from a registry - because it was pushed by mistake, contains sensitive data, or simply should no longer be available. Practice purging a container image properly: remove the tag, trace it to the manifest and blobs behind it, and make sure the image can no longer be pulled - even by digest.
Challenge on
Assemble and Publish a Multi-Platform Image from Single-Platform Variants
An internal service is halfway through a Python-to-Go rewrite: the amd64 build already runs the new Go code while arm64 still ships the legacy Python one - same API, two completely different codebases and Dockerfiles. Can you build and push a single multi-platform image from the two independent single-platform variants?
Challenge on ,
Kubernetes - Build and Deploy a Production-Ready Container Image
Combine multi-stage builds, build-time arguments, non-root users, and Pod security context into a single production-grade image pipeline.
Challenge on
Build and Push a Multi-Platform Container Image
Combine your knowledge of QEMU emulation, cross-compilation, and remote builders to build and push a multi-platform container image (linux/amd64 + linux/arm64) to a registry.
Challenge on
Union Mount Container Image Layers into a Flat Filesystem Using OverlayFS
Save a container image as an OCI layout, extract its filesystem layers, and mount them together using OverlayFS to get a flat container-like rootfs.
Challenge on ,
Build a Production-Ready Python Container Image: FastAPI Application
Learn how to build a secure, lightweight, and production-ready Python container image for a FastAPI application by following this hands-on challenge full of practical tips and tricks. Solutions for pip + venv, poetry, and uv are included.
Challenge on ,
Build a Production-Ready Go Container Image: A Dynamically Linked Application
Learn how to build a secure, lightweight, and production-ready container image for a dynamically linked Go application by following this hands-on challenge full of practical tips and tricks.