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

[Ryan Harper]

* Daniel P. Berrang? <berrange at redhat.com> [2019-11-21 06:21]:
> 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.

NoCloud already supports a 'seedfrom' parameter which points to a
file or url; a vsock-based NoCloud would need some convention for
which channel/port it would use by default.  cloud-init could
look for the vsock device, though it's possible for vsock to be present
but not have any userdata/metadata for cloud-init.

For the metadata, http over the vsocket to fetch the same files that'd
normally be in the NoCloud datasource should be straightforward.

> 
> Regards,
> Daniel
> -- 
> |: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org         -o-            https://fstop138.berrange.com :|
> |: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|

-- 
Ryan Harper
Canonical, Ltd.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 473 bytes
Desc: Digital signature
URL: <http://listman.redhat.com/archives/virt-tools-list/attachments/20191121/f65998e4/attachment.sig>