Re: sd-varlink and socket activation?

[Thorsten Kukuk <kukuk@xxxxxxxx>]

Hi Nils,

On Wed, Jan 8, 2025 at 7:59 PM Nils Kattenbeck <nilskemail@xxxxxxxxx> wrote:
>
> Hi,
>
> do you set Accept=yes in your socket unit?

No, but same problem.

> I think ask-password.c and hostnamed.c might be some pretty barebones
> services to which you may compare your code - the former uses
> Accept=yes and the latter does not.

Thanks for the hint with ask-password.c. I looked at hostnamed.c and
others already, but they are using a mix of varlink/dbus and a special
loop with idle check.
Comparing with ask-password.c:  I shouldn't call
sd_varlink_server_listen_address() if I do socket activation...

It's working now,
Thorsten

> If you do not use Accept=yes but terminate as soon as the only
> connection leaves it might result in quickly starting the service many
> times which could be penalized.
>
> Cheers, Nils
>
> On Wed, Jan 8, 2025 at 5:15 PM Thorsten Kukuk <kukuk@xxxxxxxx> wrote:
> >
> > )
> > Hi,
> >
> > While sd-varlink works fine for me with always running daemons, I have
> > a bigger problem with socket activation.
> > So having "wtmpdbd.socket" and "wtmpdbd.service".
> >
> > If a tool connects to the socket, the daemon gets started, answers the
> > query and after the last connection is closed, quits.
> > But this only works for the first connection, every try afterwards
> > leads to ECONNREFUSED.
> > Any ideas what I'm missing?
> >
> > The code is more or less:
> >  _cleanup_(sd_varlink_server_unrefp) sd_varlink_server *varlink_server = NULL;
> > sd_varlink_server_new
> > sd_varlink_server_add_interface
> > sd_varlink_server_bind_method_many
> > sd_varlink_server_listen_address
> > sd_notify (0, "READY=1")
> > sd_varlink_server_loop_auto
> > sd_notify (0, "STOPPING=1")
> > return 0
> >
> > The output is:
> > Jan 08 16:01:05 node179 systemd[1]: Listening on wtmpdb daemon (reader socket).
> > Jan 08 16:01:14 node179 systemd[1]: Starting wtmpdb daemon...
> > Jan 08 16:01:14 node179 wtmpdbd[42187]: Starting wtmpdbd (wtmpdb) 0.50.0...
> > Jan 08 16:01:14 node179 wtmpdbd[42187]: Varlink method "ReadAll" called...
> > Jan 08 16:01:14 node179 systemd[1]: Started wtmpdb daemon.
> > Jan 08 16:01:14 node179 systemd[1]: wtmpdbd.service: Deactivated successfully.
> >
> > Thanks,
> > Thorsten
> >
> > --
> > Thorsten Kukuk, Distinguished Engineer, Senior Architect, Future Technologies
> > SUSE Software Solutions Germany GmbH, Frankenstraße 146, 90461
> > Nuernberg, Germany
> > Managing Director: Ivo Totev, Andrew McDonald, Werner Knoblich (HRB
> > 36809, AG Nürnberg)



-- 
Thorsten Kukuk, Distinguished Engineer, Senior Architect, Future Technologies
SUSE Software Solutions Germany GmbH, Frankenstraße 146, 90461
Nuernberg, Germany
Managing Director: Ivo Totev, Andrew McDonald, Werner Knoblich (HRB
36809, AG Nürnberg)