[vdsm] Per device custom properties

[Yair Zaslavsky]

----- Original Message -----
> From: "Itamar Heim" <iheim at redhat.com>
> To: "Yair Zaslavsky" <yzaslavs at redhat.com>
> Cc: "Itzik Brown" <ItzikB at mellanox.com>, "Michael Pasternak" <mpastern at redhat.com>, "Eldan Hildesheim"
> <ehildesh at redhat.com>, vdsm-devel at lists.fedorahosted.org, "Eli Mesika" <emesika at redhat.com>, arch at ovirt.org,
> izikb at mellanox.com
> Sent: Sunday, April 21, 2013 12:17:51 AM
> Subject: Re: [vdsm] Per device custom properties
> 
> On 03/20/2013 09:43 AM, Yair Zaslavsky wrote:
> >
> >
> > ----- Original Message -----
> >> From: "Itzik Brown" <ItzikB at mellanox.com>
> >> To: "Dan Kenigsberg" <danken at redhat.com>, "Assaf Muller"
> >> <amuller at redhat.com>, "Yair Zaslavsky"
> >> <yzaslavs at redhat.com>, "Eldan Hildesheim" <ehildesh at redhat.com>,
> >> izikb at mellanox.com
> >> Cc: vdsm-devel at lists.fedorahosted.org, arch at ovirt.org, "Irena Berezovsky"
> >> <irenab at mellanox.com>
> >> Sent: Wednesday, March 20, 2013 9:17:08 AM
> >> Subject: RE: [vdsm] Per device custom properties
> >>
> >> Hi,
> >>
> >> I think that this feature is a good start for enabling vendor
> >> specific hints which apply to VM Network/Disk devices.
> >> There is a need to add migration  hooks to the list.
> >>
> >> Itzik
> >>
> >> -----Original Message-----
> >> From: Dan Kenigsberg [mailto:danken at redhat.com]
> >> Sent: יום ג 19 מרץ 2013 17:12
> >> To: Assaf Muller; Yair Zaslavsky; Eldan Hildesheim;
> >> izikb at mellanox.com
> >> Cc: vdsm-devel at lists.fedorahosted.org; arch at ovirt.org
> >> Subject: Re: [vdsm] Per device custom properties
> >>
> >> adding arch at ovirt, as this feature is cross sub-project
> >>
> >> On Sun, Mar 17, 2013 at 09:50:20AM -0400, Assaf Muller wrote:
> >>> Hi all,
> >>>
> >>> Right now we have the ability to define VM-wide properties that may
> >>> be
> >>> used by hooks.
> >>> It is time we have the same functionality on a device basis:
> >>> http://www.ovirt.org/Features/Device_Custom_Properties
> >>
> >> This feature page needs some love and attention.
> >>
> >> * I received a private communication about the suggested GUI: there
> >>    should not be an independent vNIC action called "custom Properties"
> >>    -
> >>    the dialog for editing per-vNIC custom properties should be part of
> >>    defining a new vNIC or editting an existing one. I believe Eldan
> >>    (our
> >>    GUI designer) concurs.
> >>
> >> * http://www.ovirt.org/Features/Device_Custom_Properties#Engine is
> >>    rather lacking concrete details. Yair, could you improve it, as
> >>    well
> >>    as the completely empty REST section?
> >
> > I would prefer Michael Pasternak handles REST-API.
> > Regarding the rest of the engine side- I'll assist.
> > I would consult with Eli on this, as he was/is the feature owner of VM
> > devices.
> >
> >>
> >>>
> >>> For example: If the VM has 2 disks called disk1 and disk2, and two
> >>> NICs called nic1 and nic2, and the admin (From the engine) added a
> >>> custom property qos: 0.5 for nic1 and a custom property defrag:
> >>> None
> >>> for disk2. When the VM is started we'll run a hook for nic1 with
> >>> its
> >>> XML and qos: 0.5 added as an environment variable, and a hook for
> >>> disk2 with its XML and defrag: None.
> >>>
> >>> When a device is hot plugged and it has custom properties we'll run
> >>> that hook as well.
> >>>
> >>> Implementation-wise, hot plug/unplug for disks and NICs is dead
> >>> simple
> >>> - vmCreate is more problematic:
> >>> If the user set a custom property called 'qos: 0.8' for nic3, I'd
> >>> want
> >>> it exposed as an environment variable called 'qos' for hot plug nic
> >>> hooks, but for vmCreate I'd like to prefix the nic's alias.
> >>>   However,
> >>> when vmCreate is called we don't have the aliases for NICs and
> >>> disks.
> >>>
> >>> The proposed solution is to create a new hook point called
> >>> something
> >>> like: 'before_device_creation' that will be called before vmCreate.
> >>> We'll then call that hook specifically for devices that contains
> >>> custom properties, as described in the second paragraph of this
> >>> mail.
> >>>
> >>>
> >>> I would love to hear smarter ideas before I move forward. Thanks!
> >>
> >> I find it quite intuitive, but I'd rather hear if it feats Izik's use
> >> case.
> >>
> >> Dan.
> >>
> > _______________________________________________
> > vdsm-devel mailing list
> > vdsm-devel at lists.fedorahosted.org
> > https://lists.fedorahosted.org/mailman/listinfo/vdsm-devel
> >
> 
> one point for consideration is we may want to make custom properties
> "managed entities" in the future, rather than 'blobs'. this will
> especially be important to allow managing permissions on them.

+1 - I think we already discussed that in the past. I had a "deja vu" about it, when I went over
the current Wiki.


>