Add timecounter option to rc.conf

[Dag-Erling Smorgrav]

"Poul-Henning Kamp" <phk at phk.freebsd.dk> writes:
> I on the other hand think that by now /etc/rc.conf has so many knobs
> and handles that it is practically impossible to figure out how to
> do anything without resorting to "less /etc/rc.*" to figure it out :-(

'man rc.conf' should hopefully be reasonably up to date, and
/etc/defaults/rc.conf briefly documents most of the knobs.  The main
problem is that there are knobs which aren't listed in either of these
and which I suspect even most committers never knew existed, because
our rc.d scripts were imported wholesale from NetBSD with some but
IMHO not enough adaptation.  Differences between NetBSD and FreeBSD
should have been viewed as an opportunity to improve both, but instead
the scripts were "dumbed down" to provide very little beyond what
already existed in FreeBSD.

> > (another such example is ntp.conf - the needs of most ntpd users can
> > be met with an ntp.conf generated automatically from information which
> > is already present in rc.conf)
> The new NTP4 automatic configuration stuff is promising in this respect,
> with a little luck people will need to configure nothing at all.

That would be nice, but we can still do far better than the status quo
for the current version.  We actually have some of the required knobs
(inherited from NetBSD along with the rest of rcNG) but they are not
documented and still fall a little short of what I would like to see.

I would like to have a single ntp_servers variable listing NTP servers
in the host's vicinity; if set, that list would be appended to the
ntpdate command line, and used to autogenerate ntp.conf.  Of course,
if it were empty (the default), any preexisting ntp.conf would be left
intact.  I also think ntpdate_enable and ntpd_enable should default to
YES if ntp_servers is non-empty, but that might be slightly more
controversial.

Currently, ntpdate gets its server list from the ntpdate_hosts
variable, or from ntp.conf if ntpdate_hosts is empty.  None of this is
documented, because it came from NetBSD with rcNG.  Previously, we had
to list servers in ntpdate_flags; I bet a lot of people still do,
unaware that the servers listed in ntp.conf will be appended to this
list.

DES
-- 
Dag-Erling Smorgrav - des at ofug.org