How to have locatedb created / updated automatically?
When you run that command, launchd will update the database every week automatically. On my system, the plist is set to run every Saturday at 3:15am.

Edit from OP: Yes, works, note: Also it ran once when submitted, so for me, within a few minutes I was able to use locate.  the update process runs in the background so you may have to wait a few minutes before locate then works (You'll get the "The locate database ... does not exist" message until then).