[lxc-devel] [PATCH] hooks/ubuntu-cloud-prep: add hostname to meta-data

[Scott Moser]

On Thu, 22 Aug 2013, Serge Hallyn wrote:

> Quoting Scott Moser (smoser at ubuntu.com):
> > prior to my enabling of the clone hook, the setting of the hostname
> > was being done by writing to /etc/hostname.  Instead of relying on that
> > we're now writing 'local-hostname' into the metadata for the instance.
> >
> > cloud-init then reads this and sets the hostname properly.
> >
> > The one caveat is that setting of the hostname then occurs after
> > the initial dhcp, so the hostname sent in the dhcp request would be
> > the original one.
> >
> > Should this prove problematic (possibly for avahi dns) we can revert
> > to explicitly writing the hostname into /etc/hostname as well.
>
> Hi Scott,
>
> this did manage to set the container name as hostname on first boot,
> however apparently not in time for dhcp's send gethostname().  On
> first boot, the parent dnsmasq couldn't resolve the hostname, but
> after a reboot it could.
>
> I don't mind applying the patch as is, but is that going to be a problem
> for ubuntu-cloud users?

I kind of see this as a broken design in that you're having lxc tell the
instance what its hostname is, then having the instance tell dnsmasq, and
relying on that for hostname resolution.

A better solution would be for lxc to set dnsmasq correctly so dns
resolution works independent of the instance's configuration.  lxc knows
the MAC address.

That said, I'll re-send with setting /etc/hostname also.