libvirt users - May 2012 - creating a domain

hi,

i am a bit confused on how to start an inactive domain using the python
bindings, any help would be appreciated.
(inactive as in the domain was created with?virConnect.defineXML sometime in the
past)


looks like i have to use virDomain.create, however virDomain.create needs a
defined domain xmldesc as a parameter and i am not sure on how to get that

i guess if?virConnect.create was happening right after?virConnect.defineXML i
could get the return value of?virConnect.defineXML and pass that onto
virDomain.create.
however, since the domain was created sometime in the past, i am not sure on how
to get the domain ptr which virDomain.create needs

thanks

On May 9, 2012, at 4:26 PM, John Wayne <m01z04-libvirt at yahoo.com>
wrote:
> hi,
> 
> i am a bit confused on how to start an inactive domain using the python
bindings, any help would be appreciated.
> (inactive as in the domain was created with virConnect.defineXML sometime
in the past)
> 
> 
> looks like i have to use virDomain.create, however virDomain.create needs a
defined domain xmldesc as a parameter and i am not sure on how to get that
> 
> i guess if virConnect.create was happening right after virConnect.defineXML
i could get the return value of virConnect.defineXML and pass that onto
virDomain.create.
> however, since the domain was created sometime in the past, i am not sure
on how to get the domain ptr which virDomain.create needs
> 
> thanks
> 
> 
John,

I think you are confusing methods. libvirt.virDomain.create() just takes a
virDomain object while libvirt.virConnect.createXML() takes an xmldesc.

$ python
>>> import libvirt
>>> conn = libvirt.open("qemu:///system")
>>> dom = conn.lookupByName("my-machine")
>>> dom.create()
Should do the trick.

--
Doug Goldstein

On 05/09/2012 11:26 PM, John Wayne wrote:
> hi,
>
> i am a bit confused on how to start an inactive domain using the python
bindings, any help would be appreciated.
> (inactive as in the domain was created with virConnect.defineXML sometime
in the past)
>
>
> looks like i have to use virDomain.create, however virDomain.create needs a
defined domain xmldesc as a parameter and i am not sure on how to get that
Yes you need to use the create method of virDomain object.
>
> i guess if virConnect.create was happening right after virConnect.defineXML
i could get the return value of virConnect.defineXML and pass that onto
virDomain.create.
> however, since the domain was created sometime in the past, i am not sure
on how to get the domain ptr which virDomain.create needs
To lookup a previously defined domain, you have to use one of lookup 
methods provided by the virConnect object. An example with interactive 
python session:

$ python
Python 2.7.2 (default, Nov  3 2011, 10:48:09)
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or
"license" for more information.
 >>> import libvirt
 >>> conn = libvirt.open("")
 >>> dom = conn.lookupByName("Bare")
 >>> dom.create()
0
 >>> conn.listDomainsID()
[3]

You also may use lookupByUUID if you prefer UUIDs.

Peter

On Wed, May 09, 2012 at 02:26:47PM -0700, John Wayne
wrote:
> looks like i have to use virDomain.create, however virDomain.create
> needs a defined domain xmldesc as a parameter and i am not sure on how to
get that
Have you tried one of these?

  lookupByID(self, id)
      Try to find a domain based on the hypervisor ID number
      Note that this won't work for inactive domains which have
      an ID of -1,
      in that case a lookup based on the Name or UUId need to be
      done instead.
  
  lookupByName(self, name)
      Try to lookup a domain on the given hypervisor based on
      its name.
  
  lookupByUUID(self, uuid)
      Try to lookup a domain on the given hypervisor based on
      its UUID.
  
  lookupByUUIDString(self, uuidstr)
      Try to lookup a domain on the given hypervisor based on
      its UUID.