[pkg-ntp-maintainers] Bug#370332: ntp: keep server list separate from other ntp.conf settings

[Drew Parsons]

I've noticed over the last year or so occasional updates have been made
to /etc/ntp.conf.  Because I've tried to optimise my server list to use
local servers, I've missed these changes.  During the upgrade I get the
option to accept the new version of /etc/ntp.conf or to keep my current
version, so I kept the old, not wanting to have to go through my server
list again.  

But I think some of the non-server changes to /etc/ntp.conf must have
been important, and in fact I eventually reached the point where ntp
plain failed to work, e.g.
Feb 6 13:48:53 pug ntpd_initres[5745]: ntpd returns a permission denied
error!

So I purged and reinstalled ntp to get the new ntp.conf, reset my
servers, it's all fine again at the moment (I think).

I think it must be a relatively common configuration, to want to define
your own servers but otherwise leave other ntp.conf settings at their
default values.

It would therefore make sense if the server list could be read in from a
separate file, /etc/ntp.servers say.  This could be done either as an
#include mechanism reading /etc/ntp.conf (bug #370332 says this does not
yet exist), or by the Debian postinst merging a /etc/ntp.settings
and /etc/ntp.servers to create a unified /etc/ntp.conf (not so hard to
do, right?), or by having the ntp code read servers from a server file
instead of /etc/ntp.conf (probably too fiddly compared with introducing
an #include mechanism).

The advantage would be a greatly improved ease of upgrading the general
config settings, while maintaining the same list of servers.

I was going to raise a new bug about this, but saw that Bug#370332
addresses similar concerns, so I'm adding my comments here instead.

Thanks,
Drew