Re: [libvirt] Allow custom metadata in domain configuration XML

On 01/20/2012 01:15 PM, Zeeshan Ali (Khattak) wrote: Looks like an interesting idea, as it gives applications more structure than what they would get by overloading the free-form <description>. Hmm, you didn't update docs/schemas/domaincommon.rng. But how do you write a schema that accepts a <metadata> element with arbitrary contents? </me searches the web...> http://www.oasis-open.org/committees/relax-ng/tutorial.html#IDAFLZR <define name="anyElement"> <element> <anyName/> <zeroOrMore> <choice> <attribute> <anyName/> </attribute> <text/> <ref name="anyElement"/> </choice> </zeroOrMore> </element> </define> <define name='metadata'> <element name='metadata'> <choice> <text/> <zeroOrMore> <ref name='anyElement'/> </zeroOrMore> </choice> </element> </define> 0.9.10. Is this the right level of indentation if buf itself already has indentation (such as when <domain> is nested inside <domainsnapshot>? You may need to use virBufferGetIndent() and use that to alter the fourth argument to xmlNodeDump accordingly. Unless anyone else objects to this XML addition, I think it is probably okay; but I have a couple caveats: 1. you need to add tests that prove we can parse/regenerate user XML (that is, qemuxml2xmltest.c needs a new test case, and I'd also like to see one of the snapshot xml tests covering this to ensure indentation was taken care of) 2. we probably need an API to allow the user to change this XML on the fly for a running domain. Which means you ought to investigate whether you can merge your arbitrary XML alongside Peter's patch series [1] to add <title> and alter <description>. I think that adding a new flag VIR_DOMAIN_DESCRIPTION_METADATA for use in virDomainSetDescription would do the trick, rather than adding yet another API. [1]https://www.redhat.com/archives/libvir-list/2012-January/msg00709.html Looking forward to v2. -- Eric Blake eblake(a)redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org