[rhos-list] Optimizing IT: Red Hat Virtual Event

[Perry Myers]

On 12/05/2012 06:34 PM, Ian McLeod wrote:
> (Note.  I am not on rhos-list and cannot find it on the mailman web
> interface internally.  My replies to the list are bouncing.)
> 
> On Wed, 2012-12-05 at 17:59 -0500, Perry Myers wrote:
>> On 12/05/2012 05:34 PM, Steve Loranz wrote:
>>>> If anyone got a work script that uses OZ to build, then push images
>>>> into Glance, please share.
>>>
>>> This is exactly what imagefactory will do for you.
>>>
>>> Please realize that imagefactory is plugin based. Our current OS
>>> plugins pretty much just wrap Oz. The Cloud plugins take the
>>> resulting OS images and manage whatever needs to be done to prepare
>>> them for and push them to the cloud. If all you want is Openstack,
>>> then only install the Openstack cloud plugin. This was done precisely
>>> to decouple different areas of the code and make it easier for
>>> developers focused on a specific OS or a specific cloud to work on
>>> supporting that OS or cloud. For the user it allows imagefactory to
>>> be as focused or as flexible as needed.
>>
>> One thing that might be useful would be to have IF/Oz utilize an
>> OpenStack VM to do the image building vs. using a standalone kvm host.
>> Is this something that could be done?
> 
> The short answer is "Probably, with modifications." 
> 
> Oz uses libvirt and has some baked in assumptions about talking to a
> local KVM or emulated QEMU machine.  We could likely tease these out and
> use a VM provided by Nova.  JRD asked me a couple of days ago to look
> into this in more detail.  I've yet to do so.  Apologies.  A further
> complication is that both Oz and Factory make fairly heavy use of
> libguestfs, which also benefits from fast local virt and cannot easily
> be offloaded to an external VM.
> 
> Another potential short answer is "Yes, effortlessly, if you can provide
> a VM container that enables nested virt."  

Interesting.  I wonder if that's a good reason to provide a nested virt
capable host type in Nova so that you can restrict where your VM is
scheduled by that constraint?  Russell, is that crazy?

> This would require a manual bootstrap of the utility image containing
> Factory/Oz.  However, once in place this presents some intriguing
> options for horizontal scaling.  An "image building 'deployable'"
> perhaps?

Sounds like you're all over it.  I wasn't sure if jrd had talked to you
about this or not.  Cheers :)