[Users] Obtain VM name from within VM?

[Yuriy Demchenko]

Hi,

Is VMpayload supported by oVirt 3.2.2 el6?
As I'm trying to set up startup hook to pass vmname via payload and 
getting nothing...

my hook code quite simple (and maybe crude):
> domxml = hooking.read_domxml()
> domain = domxml.getElementsByTagName('domain')[0]
> payloads = domxml.createElement('payloads')
> npayload = domxml.createElement('payload')
> npayload.setAttribute('type','cdrom')
> filename = domxml.createElement('file')
> filename.setAttribute('name','vmname.txt')
> content = domxml.createElement('content')
> names = domxml.getElementsByTagName('name')[0]
> vmname = names.childNodes[0].nodeValue
> text = domxml.createTextNode(vmname)
> content.appendChild(text)
> filename.appendChild(content)
> npayload.appendChild(filename)
> payloads.appendChild(npayload)
> domain.appendChild(payloads)
> hooking.write_domxml(domxml)
and from vdsm.log I can see that 'payloads' elements are created 
succesfully:
> Thread-56974::DEBUG::2013-06-18 
> 11:43:49,612::libvirtvm::1520::vm.Vm::(_run) 
> vmId=`a21a2ec8-c7fd-4a0a-8cbb-5f0ab4faa960`::<?xml version="1.0" 
> encoding="utf-8"?><domain type="kvm">
> <name>virt-gate</name>
> <uuid>a21a2ec8-c7fd-4a0a-8cbb-5f0ab4faa960</uuid>
> <memory>524288</memory>
> <currentMemory>524288</currentMemory>
> <vcpu>1</vcpu>
> <devices>
> <channel type="unix">
> <target name="com.redhat.rhevm.vdsm" type="virtio"/>
> <source mode="bind" 
> path="/var/lib/libvirt/qemu/channels/virt-gate.com.redhat.rhevm.vdsm"/>
> </channel>
> <channel type="unix">
> <target name="org.qemu.guest_agent.0" type="virtio"/>
> <source mode="bind" 
> path="/var/lib/libvirt/qemu/channels/virt-gate.org.qemu.guest_agent.0"/>
> </channel>
> <input bus="ps2" type="mouse"/>
> <channel type="spicevmc">
> <target name="com.redhat.spice.0" type="virtio"/>
> </channel>
> <graphics autoport="yes" keymap="en-us" listen="0" passwd="*****" 
> passwdValidTo="1970-01-01T00:00:01" port="-1" tlsPort="-1" type="spice">
> <channel mode="secure" name="main"/>
> <channel mode="secure" name="inputs"/>
> <channel mode="secure" name="cursor"/>
> <channel mode="secure" name="playback"/>
> <channel mode="secure" name="record"/>
> <channel mode="secure" name="display"/>
> <channel mode="secure" name="usbredir"/>
> <channel mode="secure" name="smartcard"/>
> </graphics>
> <video>
> <address bus="0x00" domain="0x0000" function="0x0" slot="0x02" 
> type="pci"/>
> <model heads="1" type="qxl" vram="65536"/>
> </video>
> <interface type="bridge">
> <address bus="0x00" domain="0x0000" function="0x0" slot="0x03" 
> type="pci"/>
> <mac address="00:1a:4a:a8:7a:07"/>
> <model type="virtio"/>
> <source bridge="vlan1"/>
> <filterref filter="vdsm-no-mac-spoofing"/>
> <link state="up"/>
> </interface>
> <interface type="bridge">
> <address bus="0x00" domain="0x0000" function="0x0" slot="0x04" 
> type="pci"/>
> <mac address="00:1a:4a:a8:7a:09"/>
> <model type="virtio"/>
> <source bridge="vlan11"/>
> <filterref filter="vdsm-no-mac-spoofing"/>
> <link state="up"/>
> </interface>
> <disk device="cdrom" snapshot="no" type="file">
> <address bus="1" controller="0" target="0" type="drive" unit="0"/>
> <source file="" startupPolicy="optional"/>
> <target bus="ide" dev="hdc"/>
> <readonly/>
> <serial/>
> </disk>
> <disk device="disk" snapshot="no" type="block">
> <address bus="0x00" domain="0x0000" function="0x0" slot="0x06" 
> type="pci"/>
> <source 
> dev="/rhev/data-center/5849b030-626e-47cb-ad90-3ce782d831b3/d786e2d5-05ab-4da6-95fc-1af791a3c113/images/4927f83f-425e-41ef-aa12-3bc249d7064b/caa56376-deab-41cd-a27c-d35fe8f33946"/> 
>
> <target bus="virtio" dev="vda"/>
> <serial>4927f83f-425e-41ef-aa12-3bc249d7064b</serial>
> <boot order="1"/>
> <driver cache="none" error_policy="stop" io="native" name="qemu" 
> type="raw"/>
> </disk>
> <memballoon model="virtio"/>
> </devices>
> <os>
> <type arch="x86_64" machine="pc">hvm</type>
> <smbios mode="sysinfo"/>
> </os>
> <sysinfo type="smbios">
> <system>
> <entry name="manufacturer">oVirt</entry>
> <entry name="product">oVirt Node</entry>
> <entry name="version">6-4.el6.centos.10</entry>
> <entry name="serial">A6902500-EA00-0706-0025-90A600EA0E0F</entry>
> <entry name="uuid">a21a2ec8-c7fd-4a0a-8cbb-5f0ab4faa960</entry>
> </system>
> </sysinfo>
> <clock adjustment="-2" offset="variable">
> <timer name="rtc" tickpolicy="catchup"/>
> </clock>
> <features>
> <acpi/>
> </features>
> <cpu match="exact">
> <model>Nehalem</model>
> <topology cores="1" sockets="1" threads="1"/>
> </cpu>
> <payloads><payload type="cdrom"><file 
> name="vmname.txt"><content>virt-gate</content></file></payload></payloads></domain>
Tried with both 'cdrom' and 'floppy' types.
However, inside guest OS (centos 6.4) I couldn't see any payload: 
/dev/sr0 contains nothing; modprobe floppy doest not finds any floppy 
devices.

Am I missing something or it's just not implemented in 3.2.2-el6?

Yuriy Demchenko

On 05/25/2013 10:54 PM, Itamar Heim wrote:
>> http://www.ovirt.org/Features/VMPayload
>>
>> That suggests I can use the API to set this up, but is this possible
>> via the administrative UI instead? Could I do this in a creation-time
>> VDSM hook?
>>
>> Thanks,
>>
>
> 1. yes, you can do it via a hook using custom properties (that what 
> the floppy/iso inject hooks were for, but they are now deprecated as 
> the vm payload makes them redundant).
>
> 2. RHEV has this in 3.1. iirc, its only available via the API though[1]
> cloud init should be available from the UI via the runonce dialog.