Docker-in-Docker

Docker-in-Docker, or dind, is a historical project demonstrating how to run a complete Docker daemon inside another Docker container. It relies on privileged container execution so nested Docker can configure cgroups, mounts, devices, and other kernel resources. A wrapper script prepares the container environment before starting the inner daemon. The image can expose that daemon over a network port or provide an interactive shell for experimentation. The project documents storage, cgroup, AppArmor, and nested-container limitations in detail. It is now obsolete because the official docker:dind image provides the same general capability in a maintained form.