Re: [libvirt] Why is avahi-daemon being started?
On Tue, Sep 07, 2010 at 09:38:15AM -0600, Eric Blake wrote:
[adding libvir-list]
On 09/07/2010 07:42 AM, Tom Horsley wrote:
> On Tue, 07 Sep 2010 13:51:09 +0100
> Adam Williamson wrote:
>
>>> I did find a "Should-start: avahi-daemon" comment in the libvirtd
>>> init script, so maybe that is the source.
>>
>> Shouldn't be. 'Should-start' means 'if this other service is
enabled, it
>> should be started before this one': it's not a strict dependency,
'this
>> other service MUST be started before this one'.
>
> Yea, changing the comment there didn't fix anything, but it was a good
> hint since I finally found the "mdns_adv" setting in the libvirtd.conf
> file and uncommenting it did finally squash avahi-daemon :-).
I'm wondering if this means that libvirt should change any of its
policies about auto-starting avahi-daemon, or at the very least, if
there is a documentation shortcoming on why libvirt defaults to enabling
this and when you might want to change that default.
libvirtd has never explicitly auto-started avahi. libvirtd uses the
avahi client library and gives it a callback to be invoked whenever
a connection to the avahi daemon is established. With the old init
system, if avahi wasn't started on boot, the callback isn't invoked
and so libvirt never registers its mdns service. The sysadmin can
start avahi at any time later, and libvirt will automatically
register with it. With system-d it sounds like creating the avahi
client will always immediately activate the avahi service. I think
there perhaps needs to be a way to prevent autostart by the avahi
client library
Regards,
Daniel
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