On 07/12/2013 05:51 PM, Kashyap Chamarthy wrote:
Heya Laine,
Here's some quick notes to associate libvirt guests to Open vSwitch.
Configure Open vSwitch
----------------------
Now that a regular Linux bridge is configured, let's try to configure an
OVS brdige and get IP addresses from that space:
Create an Open vSwitch bridge device called 'ovsbr', and display the
current state of OpenvSwitch database contents:
$ ovs-vsctl add-br ovsbr
$ ovs-vsctl show
Add a virtual ethernet interface called 'veth0' with
s/Add a virtual ethernet interface called 'veth0' with/ Add a pair of virtual
ethernet
interfaces 'veth0' and 'veth1'
$ ip link add name veth0 \
type veth peer name veth1
Add 'veth0' ethernet device to the Linux bridge 'br0', and enumerate all
bridge devices:
$ brctl addif br0 veth0
$ brctl show
Now, associate virtual ethernet device 'veth1' to the OVS bridge,
and display the current state of OpenvSwitch database contents
$ ovs-vsctl add-port ovsbr veth1
$ ovs-vsctl show
Bring up both the virtual ethernet interfaces 'veth0' and 'veth1'
$ ip link set veth0 up && \
ip link set veth1 up
Update libvirt guest's bridge source to OVS
-------------------------------------------
Install a minimal Fedora guest with Oz (or any other mechanism):
$ wget \
https://github.com/kashyapc/virt-scripts/blob/master/oz/oz-jeos.bash
$ ./oz-jeos f19-min f19
Once install is finished, define the guest XML from the current dir:
$ virsh define f19-minJul_12_2013-12
Now let's edit libvirt's guest XML file to reflect its bridge source is
OVS bridge:
$ virsh edit f19-min
The contents of the guest XML should reflect something along the below
lines:
$ virsh dumpxml f19-min | grep bridge -A8
<interface type='bridge'>
<mac address='52:54:00:a6:08:70'/>
<source bridge='ovsbr'/>
<virtualport type='openvswitch'>
<parameters interfaceid='ecdff22d-ce80-4ae7-a008-42994415084e'/>
</virtualport>
<target dev='vnet2'/>
<model type='virtio'/>
<alias name='net0'/>
<address type='pci' domain='0x0000' bus='0x00'
slot='0x03' function='0x0'/>
</interface>
Start the guest, and check the IP of it:
$ virsh start f19-jeos --console
$ ifconfig eth0
Please note, this is just a simple test, I haven't done any further experiments with
VLAN
tagging, etc.
Slightly verbose notes:
http://kashyapc.fedorapeople.org/virt/openvswitch-and-libvirt-kvm.txt
It's probably worth it to make a libvirt networking docs patch.
--
/kashyap