[avahi] Question about D-Bus activation on systemd

[Gerardo Exequiel Pozzi]

Hello

(1) I want to know if "dbus-org.freedesktop.Avahi.service" should be a 
symlink to "avahi-daemon.service" (in "/usr/lib/systemd/system"), 
otherwise if this service is not enabled (systemctl enable 
avahi-daemon.service) will not work. Of course if enabled will work 
because symlink "dbus-org.freedesktop.Avahi.service" will exist in 
"/etc/systemd/system".

For example starting cups:
--
Sep 08 13:17:05 gerardo dbus[336]: [system] Activating via systemd: 
service name='org.freedesktop.Avahi' 
unit='dbus-org.freedesktop.Avahi.service'
Sep 08 13:17:05 gerardo dbus-daemon[336]: dbus[336]: [system] Activation 
via systemd failed for unit 'dbus-org.freedesktop.Avahi.service': Unit 
dbus-org.freedesktop.Avahi.service failed to load: No such file or 
directory. See system logs and 'systemctl status 
dbus-org.freedesktop.Avahi.service' for details.
Sep 08 13:17:05 gerardo dbus[336]: [system] Activation via systemd 
failed for unit 'dbus-org.freedesktop.Avahi.service': Unit 
dbus-org.freedesktop.Avahi.service failed to load: No such file or 
directory. See system logs and 'systemctl status 
dbus-org.freedesktop.Avahi.service' for details.
--

# grep Systemd 
/usr/share/dbus-1/system-services/org.freedesktop.Avahi.service
SystemdService=dbus-org.freedesktop.Avahi.service

For example other services like "colord-sane" matches D-Bus name with 
systemd unit filename, so D-Bus activation will work without previously 
enabled it.

# grep Systemd 
/usr/share/dbus-1/system-services/org.freedesktop.colord-sane.service
SystemdService=colord-sane.service


(2) The other question is: if this service is enabled/started, the only 
way to stop it is via disable/stop, because when is stopped, is always 
reloaded. Is this behaviour expected?

# systemctl stop avahi-daemon.service
Warning: Stopping avahi-daemon.service, but it can still be activated by:
avahi-daemon.socket
Job canceled.
# systemctl disable avahi-daemon.service
# systemctl stop avahi-daemon.service
Warning: Stopping avahi-daemon.service, but it can still be activated by:
avahi-daemon.socket
# systemctl stop avahi-daemon.socket

(3) Due (2), if symlink exists in /usr/lib/systemd/system, the only way 
to stop this service is via systemctl mask/stop/unmask.


Thanks for your answers.

-- 
Gerardo Exequiel Pozzi
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