timedatex replacing systemd-timedated for NTP packages

[Tomasz Torcz]

On Thu, Nov 27, 2014 at 10:53:45PM +0100, Tom Gundersen wrote:
> On Thu, Nov 27, 2014 at 10:00 PM, Andrew Lutomirski <luto at mit.edu> wrote:
> > On Thu, Nov 27, 2014 at 12:51 PM, Tom Gundersen <teg at jklm.no> wrote:
> >> On Wed, Nov 26, 2014 at 3:10 PM, Chris Adams <linux at cmadams.net> wrote:
> >>> Once upon a time, Tomasz Torcz <tomek at pipebreaker.pl> said:
> >>>> On Wed, Nov 26, 2014 at 08:01:37AM -0600, Chris Adams wrote:
> >>>> > Once upon a time, Florian Weimer <fweimer at redhat.com> said:
> >>>> > > Do we even use the DHCP NTP server assignment?
> >>>> >
> >>>> > I believe it is used for chrony and ntpd, don't know about sysmted's new
> >>>> > implementation.
> >>>>
> >>>>   systemd-timesyncd uses DHCP-provided NTP servers only if systemd-networkd
> >>>> is used as DHCP client.
> >>>
> >> There are technical reasons for this choice, not merely NIH.
> >
> > And those technical reasons are?
> >
> > I realize that the shell-script-fu that most DHCP clients seem to
> > require is a bit messy, but it does work, and it should be more than
> > flexible enough to plug in some systemd-timesyncd controls.
> 
> 
> networkd allows consumers of network information (such as NTP servers,
> DNS resolvers, HTTP proxy brokers,...) to subscribe to this
> information (currently only via a C API [0], but could just as well
> have been dbus) and be notified of changes to it. Other DHCP clients
> will typically instead call a bunch of hooks (with env vars set) on
> every configuration change (and it is then presumably the job of the
> hook to instruct the NTP client, or whatever else, to change its
> config).

  Nb. chronyd's unit in Fedora has:
ExecStartPost=/usr/libexec/chrony-helper add-dhclient-servers

  This is a script which gets NTP servers names from dhclient and
feeds them to chronyd.  Nothing prevents extending this script
to get data from networkd, too.

  (sorry about slight offtopic).

-- 
Tomasz Torcz               "Never underestimate the bandwidth of a station
xmpp: zdzichubg at chrome.pl    wagon filled with backup tapes." -- Jim Gray