[libvirt] [PATCH] qemu: Allow empty script path to <interface/>

[Kashyap Chamarthy]

On Thu, Feb 02, 2017 at 03:29:15PM +0000, Daniel P. Berrange wrote:
> On Thu, Feb 02, 2017 at 04:21:39PM +0100, Michal Privoznik wrote:
> > On 02/02/2017 02:56 PM, Daniel P. Berrange wrote:
> > > On Thu, Feb 02, 2017 at 02:49:48PM +0100, Michal Privoznik wrote:
> > >> Before 9c17d665fdc5f (v1.3.2 - I know, right?) it was possible to
> > >> have the following interface configuration:
> > >>
> > >>   <interface type='ethernet'/>
> > >>     <script path=''/>
> > >>   </interface>
> > >>
> > >> This resulted in -netdev tap,script=,.. Fortunately, qemu helped
> > >> us to get away with this as it just ignored the empty script
> > >> path. However, after the commit mentioned above it's libvirtd
> > >> who is executing the script. Unfortunately without special
> > >> case-ing empty script path.
> > >>
> > >> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> > > 
> > > This was always invalid input and the fact that it happened
> > > to work in the past is just luck. Since this has been broken since
> > > 1.3.2 there's plenty of libvirt releases that reject this, and so
> > > any app realistically has to be fixed to omit the <script> entirely
> > > if they want any portability. As such I don't think we need to "fix"
> > > this.
> > 
> > Fair enough. Although, 1.3.2 was not that long time ago (~a year). BTW:
> > it's openstack who is still using this.
> > 
> > https://bugzilla.redhat.com/show_bug.cgi?id=1412834

IIUC, this bug was filed to handle the case of _existing_ VMs that were
not launched with the patch that you point to below.

> Seems nova has already been fixed in both master & stable branches
> 
>   https://bugs.launchpad.net/nova/+bug/1649527


-- 
/kashyap