def write_xml(xml)
      fname = "#{@appliance_name}.xml"
      File.open("#{@dir.tmp}/#{fname}", 'w'){|f| f.write(xml)}
      register_deliverable(:xml => fname)
    end
def write_xml(xml)
      fname = "#{@appliance_name}.xml"
      File.open("#{@dir.tmp}/#{fname}", 'w'){|f| f.write(xml)}
      register_deliverable(:xml => fname)
    end
Write domain XML to file