Re: [Qemu-devel] [PATCH RFC v3 for-2.9 09/11] rbd: Revert -blockdev parameter password-secret

[Markus Armbruster <armbru@redhat.com>]

"Daniel P. Berrange" <berrange@redhat.com> writes:

> On Mon, Mar 27, 2017 at 03:26:33PM +0200, Markus Armbruster wrote:
>> This reverts a part of commit 8a47e8e.  We're having second thoughts
>> on the QAPI schema (and thus the external interface), and haven't
>> reached consensus, yet.  Issues include:
>> 
>> * BlockdevOptionsRbd member @password-secret isn't actually a
>>   password, it's a key generated by Ceph.
>> 
>> * We're not sure where member @password-secret belongs (see the
>>   previous commit).
>> 
>> * How @password-secret interacts with settings from a configuration
>>   file specified with @conf is undocumented.  I suspect it's untested,
>>   too.
>> 
>> Let's avoid painting ourselves into a corner now, and revert the
>> feature for 2.9.
>> 
>> Note that users can still configure an authentication key with a
>> configuration file.  They probably do that anyway if they use Ceph
>> outside QEMU as well.
>
> NB, this makes blockdev-add largely useless for RBD from libvirt's POV,
> since we rely on the password-secret facility working to support apps
> like openstack which won't configure the global config file for RBD.

Libvirt could still supply a *local* configuration file.

> Not a regression though, since blockdev-add is new - just means we won't
> be able to use the new feature yet :-(

Unfortunate if true, but QMP interfaces need to be stable, and this one
clearly needs more thought.