Re: Bug#727708: init multiple instances of a daemon
Daniel Pocock <daniel@pocock.com.au> writes:
> This email is not so much about the change of init system but just about
> the multiple-instance problem, regardless of which init we use. It is
> not a huge hassle but it is something that could be handled more
> smoothly.
> Some packages provide a way to start multiple instances in one shot from
> their init script, e.g.
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=433660
> which does it in such a way that a single invocation of the init script
> hits all instances (e.g. starting all when you may only want to start one).
This is something that I specifically looked at when evaluating the
features of upstart and systemd (I haven't been able to find the necessary
documentation for OpenRC), and I'm happy to report that they both have
mechanisms for doing this. upstart calls this "instances" and systemd
calls this "unit templates". Both allow you to write a single service
configuration file that can then be started multiple times with differing
parameters, creating independent services from the same configuration.
I haven't yet actually done this myself, so I don't have the experience
required to compare the implementations directly yet. I'm hoping to get a
chance to look at it once I finish converting my first service to upstart
and systemd support. I have a package now (kstart) that would benefit
greatly from this for one of its common use cases (running daemons that
maintain live Kerberos ticket caches from system keytabs).
--
Russ Allbery (rra@debian.org) <http://www.eyrie.org/~eagle/>
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