[infra] About create a Jenkins job for vdsm functional tests

[Ewoud Kohl van Wijngaarden]

On Fri, Nov 30, 2012 at 09:55:39AM +0800, Zhou Zheng Sheng wrote:
> on 11/30/2012 02:40, Ewoud Kohl van Wijngaarden wrote:
> >On Thu, Nov 29, 2012 at 01:53:00PM +0200, Dan Kenigsberg wrote:
> >>On Thu, Nov 29, 2012 at 05:46:32PM +0800, Zhou Zheng Sheng wrote:
> >>>I think the oVirt Jenkins setup maybe different from a laptop, and you
> >>>may have many other concerns. Is there anything I can help?
> >>We are in a constant want of slaves, but I hope that even without you
> >>donating one, Eyal can borrow your job and run it on "master" branch
> >>(and in the future, on every whitelisted post).
> >I feel like a job that modifies the system state is likely to fail (care
> >must be taken to to run it twice for example). We're working hard on
> >adding more slaves and are close to getting some more power. Maybe we
> >can set up VMs dedicated to that kind of job? Max 1 job, relative little
> >resources so we can have a couple of those.
> >
> I agree on running functional tests in VM. We can create disk
> snapshot for the VM, if the guest system fails in functional tests,
> just restore the snapshot.
> We can utilize snapshot moded of QEMU as well. In a snapshot mode
> VM, changes to the disk are not written to the image, but to a temp
> file. If the guest OS fails, we can just shutdown the VM, so the
> changes in the temp file are discarded. When the VM is started
> again, it goes to the previous good state. When we need to update
> the packages or edit network settings in the VM, just switch off
> snapshot mode. I wrote a simple script to do snapshot mode switching
> for a libvirtd managed VM. It requires shutting down the guest to
> take effect.
>
> To run VM creating tests on a VM slave, we can use the nested KVM or
> faqemu hook in VDSM.

That certainly sounds like a very good solution. We haven't reached a
conclusion about running just libvirt or ovirt but it sounds like both
will work.