How to put FreeBSD configuration under Revision Control?
Solution 1:
If you just want to track the changes of your own configurations on the same local host, you can happily use RCS.
A wonderful and easy howto is available on the internet.
Solution 2:
It isn't the same, and I wish someone would submit patches to etckeeper to support pkg, but an alternative might be to just snapshot the entire filesystem, if your /etc is on zfs.