Regarding turning Dockerfiles into a MicroVM: https://gruchalski.com/posts/2021-03-23-introducing-firebuil..., on GitHub: https://github.com/combust-labs/firebuild. This could get you started. Plenty of moving parts in that problem. Many root OS’s, many inits, … Difficult to pull this off by one person without any particular reason so I kinda suspended the project but who knows, seems like people want it so might be a good idea to reboot it.

Disclaimer: I’m the author.