[Users] ovirt VM custom properties

[Itamar Heim]

On 02/02/2012 10:51 PM, Brown, Chris (GE Healthcare) wrote:
> Andy,
> Many thanks!
> That got me going the right direction.
> I did some extensive testing of with this. Here are the changes I made but basically what I do is:
> - If the user specifies a custom property of usbtablet, just rewrite the input tag with:
> <input type='tablet' bus='usb'/ id='input0'>
> This will of course rewrite the existing<input type='mouse' bus='ps2'/>
> But in this case we know we desire usbtablet so just re-write with what we want.
> For non problematic guests or guests to which the agent can be installed we simply remove the custom property after the agent is added.
> For legacy guests all the way back to redhat 7.3 and win98/win2k etc we can simply use usbtablet for now.
> Once the issues with the mouse input issues with the aforementioned guest types are resolved we again won't need this (hopefully).

how about formalizing this into a patch for the vdsm custom hooks library?

>
> - Chris
>
> #!/usr/bin/python
> # VDSM Hook Script for RHEV/oVirt
> # Enables USB tablet support for a guest
> # use rhevm-config for RHEV or engine-config for oVirt to add UserDefinedVMProperties
> # EX: rhevm-config -s UserDefinedVMProperties='usbtablet=^(true|false)$' --cver=3.0
> # Remember to restart jboss
> # Use VM custom property usbtablet=true in vm configuration (Custom Properties)
>
> import os
> import sys
> import hooking
> import traceback
>
>
> if os.environ.has_key('usbtablet'):
>      try:
>          sys.stderr.write('usbtablet requested\n')
>          domxml = hooking.read_domxml()
>
>          devices = domxml.getElementsByTagName('devices')[0]
> 	inputdev = domxml.getElementsByTagName('input')[0]
>
> 	inputdev.setAttribute('bus', 'usb')
> 	inputdev.setAttribute('type', 'tablet')
> 	inputdev.setAttribute('id', 'input0')
>          hooking.write_domxml(domxml)
> 	sys.stderr.write('usbtablet support enabled\n')
>
>      except:
>          sys.stderr.write('usbtablet: [unexpected error]: %s\n' % traceback.format_exc())
>          sys.exit(2)
>
>
> -----Original Message-----
> From: Andrew Cathrow [mailto:acathrow at redhat.com]
> Sent: Wednesday, February 01, 2012 5:01 PM
> To: Brown, Chris (GE Healthcare)
> Cc: users at ovirt.org
> Subject: Re: [Users] ovirt VM custom properties
>
>
> Not tested, no error handling (eg. does the element exist already) but ...
>
>
>
> #!/usr/bin/python
>
> import os
> import sys
> import hooking
> import traceback
>
>
> if os.environ.has_key('usbtablet'):
>      try:
>          sys.stderr.write('tablet: adding usbtablet support\n')
>          domxml = hooking.read_domxml()
>
>          devices = domxml.getElementsByTagName('devices')[0]
>          tablet = domxml.createElement('input')
>          tablet.setAttribute('bus', 'usb')
>
>          devices.appendChild(tablet)
>
>          hooking.write_domxml(domxml)
>      except:
>          sys.stderr.write('tablet: [unexpected error]: %s\n' % traceback.format_exc())
>          sys.exit(2)
>
>
> ----- Original Message -----
>> From: "Chris Brown (GE Healthcare)"<Christopher.Brown at med.ge.com>
>> To: "Andrew Cathrow"<acathrow at redhat.com>
>> Cc: users at ovirt.org
>> Sent: Wednesday, February 1, 2012 5:20:09 PM
>> Subject: RE: [Users] ovirt VM custom properties
>>
>> Thanks Andy,
>> I was afraid that might be case ;)
>> I'll check out the examples and see what I can come up with.
>> - Chris
>>
>> -----Original Message-----
>> From: Andrew Cathrow [mailto:acathrow at redhat.com]
>> Sent: Wednesday, February 01, 2012 3:29 PM
>> To: Brown, Chris (GE Healthcare)
>> Cc: users at ovirt.org
>> Subject: Re: [Users] ovirt VM custom properties
>>
>>
>>
>> ----- Original Message -----
>>> From: "Chris Brown (GE Healthcare)"<Christopher.Brown at med.ge.com>
>>> To: users at ovirt.org
>>> Sent: Wednesday, February 1, 2012 4:16:35 PM
>>> Subject: [Users] ovirt VM custom properties
>>>
>>>
>>>
>>>
>>>
>>> In an effort to work around the mouse issues with spice consoles and
>>> certain guests I had an idea for the time being.
>>>
>>> My thought process is to leverage custom properties to enable
>>> usb-tablet support on said guests.
>>>
>>> -->  (
>>> http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Virtualization/3.
>>> 0/html/Administration_Guide/VDSM_Hooks.html
>>> )
>>>
>>>
>>>
>>> I perused the available documentation and it appears that these
>>> custom properties are ultimately fed into the generated libvirt
>>> domain xml.
>>>
>>> Thus sifting through -->
>>> http://libvirt.org/formatdomain.html#elementsInput we can pass in:
>>>
>>> <devices>
>>>
>>> <input type='tablet' bus='usb'/ id='input0'>
>>>
>>> </devices>
>>>
>>>
>>>
>>> The issue I am hung up on is that since this contains multi-level
>>> elements can this even be specified as a custom property?
>>
>> The custom property wouldn't contain the XML it would contain data you
>> want to pass to a hook script eg. addTablet=true, then it's down to
>> your hook script to add the appropriate element to the device node in
>> the libvirt xml.
>> There's a number of good examples in the vdsm git repo.
>>
>>
>>>
>>> If so can one of the ovirt developers provide an example on how to
>>> go about it?
>>
>>
>>>
>>>
>>>
>>> - Chris
>>> _______________________________________________
>>> Users mailing list
>>> Users at ovirt.org
>>> http://lists.ovirt.org/mailman/listinfo/users
>>>
>>
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