Ask HN: What's wrong with FreeBSD Jails?
I see a lot of people going with Docker for shipping products. Why don't more people choose Jails? Is there anything wrong with it? From what I can gather it's a far more mature implementation of containers.
Finally, jails do lack a bit of the functionality that lets docker do some things - but that isn't something that can't exist, an in fact there are certain signs that such instrumentation might be in the process of being written: https://twitter.com/FiLiS/status/894651614002393088.
FreeBSD jails can't just be easily ported to any platform, as they're not designed for portability - kernel-features being portable wasn't really a thing back in the late 1990s when jails were developed. They're designed to contain software (in fact, the title of the original paper is quite demonstrably "confining the omnipotent root"), which is why they're the first actual type of container (chroots original purpose isn't known by anyone but Bill Joy and while he isn't saying anything much on the subject, its first documented use that I know of was building BSD in a clean enviroment).