[ovirt-devel] [vdsm] Engine XML: metadata and devices from XML

[Francesco Romani]

On 03/16/2017 08:03 PM, Francesco Romani wrote:
> On 03/16/2017 01:26 PM, Francesco Romani wrote:
>> On 03/16/2017 11:47 AM, Michal Skrivanek wrote:
>>>> On 16 Mar 2017, at 09:45, Francesco Romani <fromani at redhat.com> wrote:
>>>>
>>>> We talked about sending storage device purely on metadata, letting Vdsm
>>>> rebuild them and getting the XML like today.
>>>>
>>>> In the other direction, Vdsm will pass through the XML (perhaps only
>>>> parts of it, e.g. the devices subtree) like before.
>>>>
>>>> This way we can minimize the changes we are uncertain of, and more
>>>> importantly, we can minimize the risky changes.
>>>>
>>>>
>>>> The following is  a realistic example of how the XML could look like if
>>>> we send all but the storage devices. It is built using my pyxmlpickle
>>>> module (see [3] below).
>>> That’s quite verbose. How much work would it need to actually minimize it and turn it into something more simple.
>>> Most such stuff should go away and I believe it would be beneficial to make it difficult to use to discourage using metadata as a generic junkyard
>> It is verbose because it is generic - indeed perhaps too generic.
>> I can try something else based on a concept from Martin Polednik. Will
>> follow up soon.
> Early preview:
> https://gerrit.ovirt.org/#/q/status:open+project:vdsm+branch:master+topic:virt-metadata-compact
>
> still plenty of TODOs, I expect to be reviewable material worst case
> monday morning.

This is how typical XML could look like:

    <metadata>
        <ovirt-tune:qos />
        <ovirt-vm:vm />
        <devices>
            <ovirt-instance:graphics>
                <specParams>
                    <fileTransferEnable>true</fileTransferEnable>
                    <copyPasteEnable>true</copyPasteEnable>
                    <displayIp>192.168.1.51</displayIp>
                    <keyMap>en-us</keyMap>
                    <spiceSslCipherSuite>DEFAULT</spiceSslCipherSuite>
                   
<spiceSecureChannels>smain,sinputs,scursor,splayback,srecord,sdisplay,ssmartcard,susbredir</spiceSecureChannels>
                    <displayNetwork>ovirtmgmt</displayNetwork>
                </specParams>
            </ovirt-instance:graphics>
            <ovirt-instance:disk>
                <specParams>
                    <path />
                </specParams>
            </ovirt-instance:disk>
            <ovirt-instance:disk>
                <specParams />
                <domainID>c578566d-bc61-420c-8f1e-8dfa0a18efd5</domainID>
                <volumeID>5c4eeed4-f2a7-490a-ab57-a0d6f3a711cc</volumeID>
                <poolID>5890a292-0390-01d2-01ed-00000000029a</poolID>
                <imageID>66441539-f7ac-4946-8a25-75e422f939d4</imageID>
            </ovirt-instance:disk>
        </devices>
    </metadata>

still working on this

-- 
Francesco Romani
Red Hat Engineering Virtualization R & D
IRC: fromani