User Mode Linux

The UML driver uses a Podman rootless container to allow easy attaching / detaching from the tty, to allow fully rootless networking and for easier machine management.

This is built using koble-fs and is published at docker.io/b177y/uml-runner.

It is an ubuntu container image with the tools needed for running and managing UML instances. The entrypoint script sets up interfaces / mount points, then runs the UML kernel command.

The UML filesystem is built using koble-fs. It is based on the same filesystem as that used for the Podman driver but contains additions needed for UML, and is formatted as an ext4 image.

The kernel is built using koble-kernel. For docs on building and modifying the kernel for Koble see the docs.