For those unfamiliar with FreeBSD, this is using base OS tools to manually create this type of immutable jail/container. This can be done with 'less effort' by using a jail manager.
Jail managers come and go. Base OS tools stay and are getting better and better. I would definitely stay away from ezjail as it us quite old, active development or even maintenance has stopped long time ago.
Author of the article seem to know what they are doing so I'm puzzled why they don't use `bsdinstall jail /path/to/jail` to implement basejail instead of manually unpacking archives.
No need for separate custom rc script to start `lo1`, it can be done with `cloned_interfaces` directive in rc.conf.
Updating and upgrading jails by passing `-b /path/to/jail` to `freebsd-update` works, but new recommended way has lately been `-j <jailname>`.
Cool article overall, the beauty of FreeBSD is also in possibility to do things in many different ways.
