Re: [Qemu-devel] converging around a single guest agent

[Barak Azulay <bazulay@redhat.com>]

On Tuesday 15 November 2011 21:45:42 Perry Myers wrote:
> On 11/15/2011 01:08 PM, Subhendu Ghosh wrote:
> > On 11/15/2011 01:01 PM, Perry Myers wrote:
> >> On 11/15/2011 12:24 PM, Barak Azulay wrote:
> >>> Hi,
> >>> 
> >>> One of the breakout sessions during the ovirt workshop [1] was about
> >>> the guest
> >>> tools, and focused mainly on the ovirt-guest-agent [2].
> >>> 
> >>> One of the issues discussed there, was the various existing guest
> >>> agents out
> >>> there, and the need to converge the efforts to a single agent that
> >>> will serve
> >>> all.
> >>> 
> >>> while 4 agents were mentioned (Matahari, vdagent, qemu-ga&
> >>> ovirt-guest-agent)
> >>> during that discussion, we narrowed it down to 2 candidates:
> >>> 
> >>> qemu-ga (aka virt-agent):
> >>> -------------------------
> >>> - Qemu specific - it was aimed for specific qemu needs (mainly
> >>> quiesce guest
> >>> I/O)
> >>> - Communicates directly with qemu  (not implemented yet)
> >>> - Supports ?
> >>> - So far linux only
> >>> - written in C
> >>> 
> >>> Ovirt-guest-agent:
> >>> ------------------
> >>> - Has been around for a long time (~5 years) - considered stable
> >>> - Started as rhevm specific but evolved a lot since then
> >>> - Currently the only fully functional guest agent available for ovirt
> >>> - Written in python
> >>> - Some VDI related sub components are written in C&  C++
> >>> - Supports a well defined list of message types / protocol [3]
> >>> - Supports the folowing guest OSs
> >>> 
> >>>    Linux: RHEL5, RHEL6 F15, F16(soon)
> >>>    Windows: xp, 2k3 (32/64), w7 (32/64), 2k8 (32/64/R2)
> >>> 
> >>> The need to converge is obvious, and now that ovirt-guest-agent is
> >>> opensourced
> >>> under the ovirt stack, and since it already produces value for
> >>> enterprise
> >>> installations, and is cross platform, I offer to join hands around
> >>> ovirt-
> >>> guest-agent and formalize a single code base that will serve us all.
> >>> 
> >>> git @ git://gerrit.ovirt.org/ovirt-guest-agent
> >>> 
> >>> Thoughts ?
> >> 
> >> +1
> >> 
> >> The only downside that I concretely heard from folks re:
> >> ovirt-guest-agent was that it is written in Python.  Two thoughts there:
> >> 
> >> 1. On Windows it is compiled to an executable, so no separate python
> >> 
> >>     stack needed
> >> 
> >> 2. ovirt-guest-agent is not very large and does not bring in a lot
> >> 
> >>     (any?) additional python class dependencies above/beyond the core
> >>     language and interpreter.  Given this, the chances of dealing with
> >>     python stack issues are probably minimal and also the overhead of
> >>     including _just_ the base python interpreter in a given guest OS is
> >>     very lightweight.  Core python RPM in F16 is about 80k.


The ovirt-guest-agent also depends on pywin32 package 
(http://sourceforge.net/projects/pywin32/files/) for windows platforms 


> >> 
> >> Perry
> > 
> > If you needed WMI enablement on Windows - could you support that with
> > this arch?
> 
> I'm not a WMI expert, but google search first result on 'python WMI'
> turned up:
> 
> http://timgolden.me.uk/python/wmi/index.html

As the ovirt-guest-agent the above package uses also pywin32.