getopt For people who know how to edit
jail.conf and are managing few jails no tool is needed. In particular if you are not going to take advantage of ZFS for Jail
https://clinta.github.io/freebsd-jails-the-hard-way/
masteroman Michael was contemplating to write a book about FreeBSD jails which was semi-logical thing after four books about file systems he wrote:
- FreeBSD mastery: Storage Essentials
- FreeBSD mastery: Specialty Filesystems
- FreeBSD mastery: ZFS
- FreeBSD mastery: AdvancedZFS
I used word semi-logical because
VNET -- network subsystem virtualization infrastructure (semi-functional) is equally important for large complex deployments. I am sure Mike Lukas is perfectly capable of describing ins and outs of VNET. The only problem is that thing is not finished (see
vermaden rant) He changed his mind and wrote a very nice book about native httpd and relayd daemons on OpenBSD. I am not sure how many of such books he needs to write to make leaving but my understanding is that he is now reworking Absolute FreeBSD where he can get some sales going. The blog post you refer to is obsolete. I was heavy user of iocage before IXsystem hired of the developer for their own needs (result is py-iocage) and rack the havoc among people who were
not their paid customers.
Eventually a Polish web developer
robak (he is lurking here as well) adopted orphaned iocage and now we have
sysutils/iocell. The tool is scaled down (supports only base jail which means that the "OS is mounted" as
nullfs which is very complicated) version of original iocage. In terms of file system is ZFS specific (frequently that is the main reason people use FreeBSD) and very primitive networking. I have never tried to use to deploy hundreds of jails at the same time so I am not sure how scriptable is but for my jail hosts 10-15 jails per modest spec machine (simple network topology with all jail on the single route which is the same as the host machine) works like a charm.
The Russian developer
Ole the author of CBSD (jail/Bhyve management tool) and the person behind ClonOS is probably the most qualified person on this forum to evaluate various Jail and Bhyve utilities (personally I gave up on Bhyve and I am sticking with Xen on Alpine Linux Dom0).
So going back to OP. ezjail is not obsolete unless you need ZFS (maybe that support is added as well).
The lack of good jail management tool in the base of FreeBSD IMHO is one of those things that make people think twice before using FreeBSD for any kind virtualization. Infamous now dead PC-BSD was a pioneer of GUI/CLI jail management utility Warden. Warden never worked as advertised as Ken never had stamina to get it to production quality but it was a good idea (used to be available from ports as pcbsd-utils)