[Libvir] Semantics for ListDomains/ ListDefinedDomains

Daniel P. Berrange berrange at redhat.com
Thu Aug 24 00:23:28 UTC 2006

On Wed, Aug 23, 2006 at 05:15:26PM -0400, Daniel Veillard wrote:
> On Wed, Aug 23, 2006 at 09:22:08PM +0100, Daniel P. Berrange wrote:
> > Now it would be pretty easy for libvirt to convert the XML file passed
> > into virDefineDomain into a config file for xend & stuf it in /etc/xen
> > The hard part is the reverse - enumerating the config files in the
> > dir & turning them back into XML. I fear we may have to tackle that
> > hard part sooner rather than later so I've been trying to thing of
> > ways we could attack it. Now the key problem is that the xm config
> > files can contain/are in fact python code.
>   I could see a problem with random apps writing to /etc/ , even if run
> as root that won't fly in general. But well if the goal is compatibility
> with existing xen tools, that may be a sufficient reason.

Well there's unlikely to be random apps writing into /etc/xen unless
they're related to Xen config. We can ust blacklisted the 'xend-config.sxp'
file (& perhaps the xmexample* files)

> >  * Write a tiny parser for a trivial subset - basically enough to
> >    handle the (key, string) pairs & (key, list of string) pairs.
> >    Certainly doable - depending on how general purpose we want to
> >    get - do we care about the 'if..else' conditional used in the
> >    sample /etc/xen/xmexample.vti config file ? We can certainly
> >    make a valid case saying we don't care about this because the
> >    libvirt XML -> xm config conversion would not generate config
> >    using that capability 
>    I'm not too concerned by handling only a subset, this should be data
> and processed as such IMHO.

Sounds good.

> > Not a perfect solution, but would satisfy a great deal of common
> > use cases pretty easily without being intrusive into existing code
> > base & pretty secure.
>   We are basically in agreement :-)
> So I write that parser ? 

Sounds like we should, unless anyone (CIM guys ?) listening in has better 
suggestions ?

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