I really like the idea of gaining some (even though currently still) basic compatibility with how others (SmartOS in this case) do it.
For people who didn’t look at FreeBSD in a while however and maybe currently do, I want to recommend a close look at jail.conf and the jail utility in the base system. Read their man pages and use them and there is a great likelihood that you won’t need a jail management tool. At least not in the sense of ezjail and qjail. While I wouldn’t recommend switching if it currently works a lot of guides sadly still refer to it, when a lot of the convenience related features (config file, rc.conf, simple utility) are offered by a utility or a set of utilities in base now.
This of course isn’t the same as vmadm and some other tools, often strongly integrating with ZFS. Of course it really depends on the use case. But in case you are looking for a tool to manage jails in a generic way. Base might already offer that. :)
I used to run lots of jails on my home server. I used ezjail, then iocage, then later “the hard way” doing it myself with a couple of shell scripts.
However, I have since fully switched to using separate instances running under bhyve (managed via the excellent vm-bhyve), due to ease of upgrades and manageability. This is of course less efficient (memory/cpu/etc) and a bit slower, but it has been a big win in time-saved and reduction of headaches, for my personal needs.
I would love a new jail solution but I’m very apprehensive about adopting one. ezjails is ok but when managing lots of jails I didn’t really like its interface. iocage suit me fine, but the documentation was never very good and the completely rewrite has changed everything and added a bunch of dependencies and is not even done. I think the complete big-bang rewrite was a mistake and it has made my life more difficult. iocell exists but I’m not entirely sure if it’s backwards compatible with iocage jails or you have to remake them. And now this (which seems to have commits from the iocell maintainer). For the little video, the interface didn’t look bad but is it going to exist in 2 years? And now I need rust so it’s definitely not going into the base system anytime soon. Hopefully it’ll get in ports/pkg pretty quickly so I can use it without caring about the rust part.