[Users] Obtain VM name from within VM?

Yuriy Demchenko demchenko.ya at gmail.com
Tue Jun 18 03:59:44 EDT 2013


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. 



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