Subject: Re: [bug#32128] [PATCH 0/2] Support custom actions for Shepherd services

From: Clément Lassieur <[email-masked]>
Date: Thu, 12 Jul 2018 15:03:26 +0200

Hi Ludo,

Ludovic Courtès <[email-masked]> writes:

> Hello Guix!
>
> This is a long-awaited feature—nothing fancy, but it can certainly be
> useful as illustrated by the ‘herd schedule mcron’ example below.
>
> I suppose we can add actions for hot-swapping and reconfiguration of
> services that support it, such as nginx: <https://bugs.gnu.org/26830>.

This is fantastic!  Thank you :-)  And it looks good to me.

A few notes though (more about the Shepherd):

- It would be great to be able to use actions even when services are not
  started.  In the case of the "mcron" service, for example, it makes
  sense: one may not want to risk spawning a program while wanting to
  debug the schedule.

- It seems that sometimes the SIGCHLD handler is invoked, when the
  'running' field is not yet set.  Should CALL-WITH-BLOCKED-ASYNCS be
  used?
  
Clément