[virt-tools-list] virt-install and cloud-init, feedback wanted

[Dusty Mabe]

On 11/21/19 6:20 AM, Daniel P. Berrangé wrote:
> On Thu, Nov 21, 2019 at 11:07:24AM +0000, Richard W.M. Jones wrote:
>> On Thu, Nov 21, 2019 at 10:34:14AM +0000, Daniel P. Berrangé wrote:
>>> On Wed, Nov 20, 2019 at 08:18:01PM -0500, Dusty Mabe wrote:
>>>> Basically in Fedora CoreOS we need a generic user data mechanism that works across
>>>> platforms (x86_64, aarch64, ppc64le, s390x) and doesn't have possible race conditions.
>>>> Right now we're using `-fw_cfg` but it's not cross platform. We don't have an answer
>>>> yet: https://github.com/coreos/ignition/issues/666#issuecomment-452835654
>>>
>>> For platform portability you need to find some device that is common
>>> across all platforms, and either disk or network are the only two
>>> good options that exist today or for the forseeable future.  If those
>>> aren't acceptable then all we have left are platform specific options.
>>
>> While it's not a "good option that exists today", AF_VSOCK would be a
>> good choice to settle on in the future.  It's completely cross
>> platform, available for Windows, and doesn't interfere with existing
>> network or disk devices.
>>
>> Would needing virtio be a barrier?  Our impl of AF_VSOCK runs over
>> virtio, but there are other transports.
> 
> From a cloud-init POV, I don't see virtio as a barrier. Defining an
> AF_VSOCK data source for it should be quite straightforward really
> and they already have so many data sources, it seems reasonable
> that they'd accept one more.
> 
> On the host side there's still the task of providing a metdata
> service to expose the data, which is outside scope of virt-install.
> 

Thanks for the fruitful conversation here regarding a cross platform data source
that we could use. Is this worth us writing up into a request for an issue tracker
somewhere where it could be discussed further?

Dusty