Re: [announce] s6-2.2.0.0

From: Patrick Mahoney <pat_at_polycrystal.org>
Date: Tue, 28 Jul 2015 09:59:10 -0500

On Mon, Jul 27, 2015 at 04:28:59PM +0200, Laurent Bercot wrote:
> s6-2.2.0.0 is out.
>
> * s6-notifywhenup has been removed. Please use the ./notification-fd
> file for readiness notification.

Hi Laurent,

If I understand correctly, any 'readiness' reporting mechanism must originate
from the run script (to inherit notification-fd).

Do you have any suggestions for adding readiness support to a daemon *without
modifying that daemon*?

Previously, I had been using s6-log to match a particular line from the
daemon's log output (e.g. "$service is ready"), sending the matched line to
something like 'cd .. s6-notifywhenup echo' (note: a child process of run/log,
not run).

To support the same through the notification-fd, I can imagine a rough scheme
such as:

in run:

  background { if { s6-ftrig-wait fifodir U } fdmove 1 3 echo }

  ... run the daemon

in log/run

  pipeline -w
  {
    forstdin -d"\n" i s6-ftrig-noitfy ../fifodir U
  }

  s6-log
    - +"daemon is ready" 1
    + t n20 !"gzip -nq9" logdir


Thanks,
Patrick
Received on Tue Jul 28 2015 - 14:59:10 UTC