[Samba] nmb.service fails on pure IPv6 system

[Andrew Bartlett]

There is zero impact on disabling nmbd on an IPv6 system.

Andrew,

On Mon, 2023-07-31 at 10:17 -0500, Tim Hoke wrote:
> I'm not sure I'll have any availability soon to provide a fix.
> 
> In the end, it seems `sudo systemctl mask nmb.service` will probably
> work for me so my instance doesn't go "unhealthy". I'm not sure I
> fully understand the impact of fully disabling that service, but
> that's probably my only option right now.
> 
> Thanks,
> -Tim
> 
> On Wed, Jul 26, 2023 at 3:40 PM Andrew Bartlett <abartlet at samba.org>
> wrote:
> > On Wed, 2023-07-26 at 11:41 -0700, Jeremy Allison via samba wrote:
> > > On Wed, Jul 26, 2023 at 01:13:57PM -0500, Tim Hoke via samba wrote:
> > > > I have an IPv6 only system (no IPv4 addresses) and nmb.service goes into a
> > > > failed state saying:
> > > > 
> > > > Status: "nmbd: No local IPv4 non-loopback interfaces available, waiting for
> > > > interface ..."
> > > > 
> > > > I've seen several references to a previous bug where the service wasn't
> > > > waiting
> > > > for networking to be ready. That's _not_ my case here. Instead, I have no
> > > > IPv4
> > > > addresses, so I think it's stuck in the loop looking for non-loopback IPv4
> > > > addresses.
> > > 
> > > nmbd is not IPv6 aware and can't serve IPv6 queries. Just disable
> > > it on an IPv6-only box.
> > 
> > Tim,
> > 
> > In one sense this isn't something we can 'fix' as we don't know that an IPv4 interface won't come up shortly.
> > 
> > But we could change:
> > 		DEBUG(0,("NOTE: NetBIOS name resolution is not supported for "
> > 			 "Internet Protocol Version 6 (IPv6).\n"));
> > to DBG_NOTICE
> > This should stop systemd from saying we are 'failed'. 
> > 
> > To not be be at level 0 per 
> >  https://bugzilla.samba.org/show_bug.cgi?id=4143
> >  https://gitlab.com/samba-team/samba/-/merge_requests/3123
> > and similar to
> >  https://bugzilla.samba.org/show_bug.cgi?id=15377
> >  https://gitlab.com/samba-team/samba/-/merge_requests/3113 
> > 
> > Would you like to give that a go?  
> > 
> > If so, the (painful - sorry!) process is at https://wiki.samba.org/index.php/Contribute
> > 
> > Andrew
> > 

-- 
Andrew Bartlett (he/him) https://samba.org/~abartlet/
Samba Team Member (since 2001) https://samba.org
Samba Developer, Catalyst IT https://catalyst.net.nz/services/samba