[Libvir] Relative paths in domain XML

[Richard W.M. Jones]

What would be really useful is to allow paths (eg. to file-backed
block devices) to be relative in a useful way.  This would let you
have the domain XML configuration file & the block device files sit
next to each other to give a machine description:

  mydomain.hda.img
  mydomain.xml		# refers to <source file="mydomain.hda.img">

This isn't possible at the moment as far as I can tell, which means
you need to know which directory the files are located in, and you
can't move them around.

[As an aside, at present the QEMU driver makes no attempt to check
that the source file is an absolute path, it just passes whatever it
finds to the '-hdc' argument to qemu.]

For the command:

  virsh define mydomain.xml

One implementation would be to have virsh rewriting paths, but that
requires special knowledge of the XML format in virsh so I don't think
it's a workable idea.  Another would be to allow virsh to supply a
'base URI' (basically, the current directory) to the
virDomainDefineXML call.

Any thoughts?

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
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