Focused, hands-on DevOps and server-side problems with hints, feedback, and automated solution checks.
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.
Get container images onto a server that has no route to the Internet or access to a container registry.
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.
Learn how to build container images for non-native CPU architectures by offloading the build to a remote machine using Docker Buildx.
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.
Practice using Docker build arguments to inject version and commit metadata into a Go application during the image build.
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.
Write a Dockerfile for a simple web service and learn how Docker images can improve the application startup UX by defining sensible runtime defaults using ENV, USER, and STOPSIGNAL instructions.
Learn how to build container images for non-native CPU architectures using Go's support of cross-compilation.
Learn how to build container images for non-native CPU architectures (e.g., arm64 on an amd64 host) using QEMU user-space emulation and Docker.
