Open Stack

On Friday 19 December 2014 14:38:29 Daniel P. Berrange wrote:
> On Fri, Dec 19, 2014 at 05:34:19PM +0300, Dmitry Guryanov wrote:
> > On Friday 19 December 2014 14:17:34 Daniel P. Berrange wrote:
> > > On Fri, Dec 19, 2014 at 05:11:57PM +0300, Dmitry Guryanov wrote:
> > > > Hello,
> > > > 
> > > > If I understood correctly, there are 3 ways to provide guest OS with
> > > > some
> > > > data (SSH keys, for example):
> > > > 
> > > > 1. mount guest root fs on host (with libguestfs) and copy data there.
> > > > 2. config drive and cloud-init
> > > > 3. nova metadata service and cloud-init
> > > > 
> > > > 
> > > > All 3 methods do almost the same thing and can be enabled or disabled
> > > > in
> > > > nova config file. So which one is preferred? How do people usually
> > > > configure their openstack clusters?
> > > > 
> > > > I'm asking, because we are going to extend nova/libvirt driver to
> > > > support
> > > > our virtualization solution (parallels driver in libvirt) and it seems
> > > > it
> > > > will not work as is and requires some development. Which method is
> > > > first-priority and used by most people?
> > > 
> > > I'd probably prioritize in this order:
> > >   1. config drive and cloud-init
> > >   2. nova metadata service and cloud-init
> > >   3. mount guest root fs on host (with libguestfs) and copy data there.
> > > 
> > > but there's not much to choose between 1 & 2.
> > 
> > Thanks! Config drive already works for VMs, need to check how it will work
> > with containers, since we can't add cdrom there.
> 
> There are currently two variables wrt config drive
> 
>  - device type - cdrom vs disk
>  - filesystem  - vfat vs iso9660
> 
> For your fully virt machines I'd probably just stick with the default
> that ibvirt already supports.
> 
> When we discussed this for LXC, we came to the conclusion that for
> containers we shouldn't try to expose a block device at all. Instead
> just mount the contents of the config drive at the directory location
> that cloud-init wants the data (it was somewhere under /var/ but I
> can't remember where right now).  I think the same makes sense for
> parallels' container based guests.

That's good news, we have functions to mount host dir to container
in PCS, so we just need to add it to libvirt driver.

> 
> Regards,
> Daniel

-- 
Dmitry Guryanov