[libvirt] Expose virDomainGetAutostart through virsh?

[Daniel P. Berrange]

On Fri, Nov 09, 2012 at 01:19:01AM +0100, Guido Günther wrote:
> On Thu, Nov 08, 2012 at 03:42:49PM +0100, Daniel P. Berrange wrote:
> > On Thu, Nov 08, 2012 at 03:41:12PM +0100, Peter Krempa wrote:
> > > On 11/08/12 15:13, Daniel P. Berrange wrote:
> > > >On Wed, Nov 07, 2012 at 11:32:22AM +0100, Peter Krempa wrote:
> > > >>On 11/07/12 11:04, Ruben Kerkhof wrote:
> > > >>>Hi list,
> > > >>>
> > > >>>I'd like to check if a domain has autostart enabled. I do this now by
> > > >>>looking if there's a symlink in /etc/libvirt/qemu/autostart, but it
> > > >>>feels a bit hackish.
> > > >>>
> > > >>>Is this something that could be added to virsh?
> > > >>>Something like virsh get-autostart domain would be great.
> > > >>
> > > >>For now there are two options how to check the autostart flag:
> > > >>
> > > >>1) virsh dominfo - This is suitable to check for the state of a
> > > >>single guest. Unfortunately we have just this one output option
> > > >>where it is embedded with other information about the guest:
> > > >>
> > > >>$ virsh dominfo tr
> > > >>Id:             1
> > > >>Name:           tr
> > > >>UUID:           17f42b42-9fdd-81e3-4a93-a75021a707d3
> > > >>OS Type:        hvm
> > > >>State:          running
> > > >>CPU(s):         1
> > > >>CPU time:       200.5s
> > > >>Max memory:     53248 KiB
> > > >>Used memory:    53248 KiB
> > > >>Persistent:     yes
> > > >>Autostart:      enable				<- here!
> > > >>Managed save:   no
> > > >>Security model: none
> > > >>Security DOI:   0
> > > >>
> > > >>
> > > >>2) use virsh list --all --autostart to list guests that have the
> > > >>autostart flag enabled (also note that there are script-friendly
> > > >>outputs for virsh list --name and --uuid):
> > > >>
> > > >>$ virsh list --all --autostart
> > > >>  Id    Name                           State
> > > >>----------------------------------------------------
> > > >>  1     tr                             running
> > > >>  -     Bare                           shut off
> > > >>
> > > >>
> > > >>We're planing on adding the autostart flag as an XML element and a
> > > >>few other improvements of autostaring guests.
> > > >
> > > >I don't think the XML should be in the business of having the
> > > >autostart flag, as this is not guest configuration information.
> > > >Having it in the XML introduces the problem of maintaining the
> > > >correct synchronization between the autostart symlink and the
> > > >XML description.
> > > 
> > > Yes, that will be troublesome. It's unfortunate we still have to use
> > > the symlink approach.
> > > 
> > > >
> > > >Further, in the future I'd like to actually replace our current
> > > >autostart code, with code that just sets up systemd units to
> > > >deal with autostart.
> > > >
> > > >In such a scenario, the user will be able to toggle autostart
> > > >directly using systemd, so we don't want libvirt duplicating
> > > >that info in the XML since it won't be aware of when systemd
> > > >changes the autostart flag.
> > > 
> > > Note that there are still distros that are doing everything possible
> > > to avoid having systemd. It wouldn't be nice if we broke
> > > autostarting there.
> > 
> > Of course, not least RHEL-5 and RHEL-6. If we did support systemd,
> > we would have a compile time option to use systemd vs our current
> > autostart code.
> Can we make this runtime then? Some distroy like Debian have systemd
> optional so toggling this based on systemd actually being used would be
> most helpful.

Sure, that's possible too.

FYI, i have no plans to work on actually implmenting this feature in the
near future - just wanted to let people know about the idea.

Daniel
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