How Container Filesystem Works: Building a Docker-Like Container from Scratch (labs.iximiuz.com)

We had chroot since 1979, nobody managed to build a docker like wrapper for chroot which do not require netns?

Layered file systems (multiple filesystems mounted on the same mount point) used to be used for making CD's and DVD's "writeable".

Whenever topic of Docker inner-workings comes up, I am always reminded by this video https://www.youtube.com/watch?v=HPuvDm8IC-4