Secure a Container Registry with Authentication and TLS
Set up your own OCI-compatible container registry with username/password authentication and HTTPS - the kind of protection you'd expect before using a registry in production.
Submissions: 7/12
Challenges
Focused hands-on problems designed to help you hone your DevOps or Server Side skills. Some challenges are more educational, while others are based on real-world scenarios. The platform provides hints and feedback for each challenge, including automated solution checks.
Challenge, Medium, on
Run Your Own Container Registry
Stand up a self-hosted container registry so you can push and pull images without relying on a third-party registry. Useful for tests, internal services, air-gapped environments, or just for poking at the OCI Distribution API.
Submissions: 9/16
Challenge, Medium, on
Transfer Container Images to an Air-Gapped Environment
Get container images onto a server that has no route to the Internet or access to a container registry.
Submissions: 61/79
Challenge, Medium, on
Inspect a Container Image Without Pulling It
Explore the OCI image index, manifests, and configuration of a remote multi-platform image - without pulling a single byte of filesystem layers into the local Docker daemon.
Submissions: 27/33
A Simple Sandbox Breakout: Spot It and Stop It
Investigate a potentially compromised CI host. A sandboxed "agent" running in the background is suspected of breaking out - confirm the breach and neutralize it without taking the sandbox down.
Submissions: 29/69
Challenge, Medium, on
Build a Container Image for Another Platform Using a Remote Builder
Learn how to build container images for non-native CPU architectures by offloading the build to a remote machine using Docker Buildx.
Submissions: 37/56
Challenge, Medium, on
Squash a Bloated Container Image to Remove Waste and Leaked Credentials
A poorly structured Docker image contains leftover build dependencies and leaked private registry credentials hiding in its intermediate layers. Squash the image to produce a clean, compact version with the same runtime filesystem.
Submissions: 21/34
Challenge, Medium, on
Use Docker Build Arguments to Inject Version and Commit Metadata into a Go Binary
Practice using Docker build arguments to inject version and commit metadata into a Go application during the image build.
Submissions: 33/37
Install a Private npm Package in a Dockerfile Without Leaking Credentials
Build a container image for a Node.js app that uses a private npm package without leaking the registry credentials into the image layers.
Submissions: 18/37
Challenge, Medium, on
Write a Dockerfile for a Containerized CLI Tool
Write a Dockerfile for a simple CLI tool and learn how to use the ENTRYPOINT instruction to improve the user experience of containerized command-line applications.
Submissions: 37/53