libvirt not compatible with netplan

[Daniel Roche]

Hi,

with :
- ubuntu server 18.04 freshly installed
- network bridge configured with netplan ( by default now )

the bridge network ( br0 ) is not seem by libvirt tools
  ( either virsh iface-list, nor virt-manager )

the bridge ( br0 ) is defined in netplan like this :
----- cut here -----
network:
  ethernets:
    enp2s0:
      optional: true
  bridges:
    br0:
      addresses:
        - 192.168.8.12/24
      dhcp6: false
      gateway4: 192.168.8.1
      nameservers:
        search:
          - home.dan
        addresses:
          - 192.168.8.2
      optional: true
      interfaces:
        - enp2s0
      parameters:
        stp: yes
        forward-delay: 0
  version: 2
----- cut here -----

the network bridge is working perfectly, but is not seen by libvirt
i have tried several parameters ( stp, forward-delay ...) but nothing change.

if i revert back the network configuration to ifupdown
( installing ifupdown package, removing netplan config file, and creating /etc/network/interface )

then the libvirt tools ( virsh or virt-manager ) are working again with the defined bridge.

Best Regards

[Christian Ehrhardt  (paelzer)]

Hi Daniel,
thanks for your report.

The issue that libvirt can't "see" all devices existed quite a while actually.
Whatever you have through networkd or NetworkManager was invisible.
This is due to netcf being the driver for the backend and this is - as you already realized - only compatible with ifupdown.

bug 1764314 holds a discssion with more details on it so I'll mark yours here as a dup.

[Ahmed (akha666-f)]

Hi all,
I've managed libvirt to work with netplan's bridges, look for this example under Bridging section

https://netplan.io/examples

libvirtd would be configured to use this bridge by adding the following content to a new XML file under /etc/libvirtd/qemu/networks/. The name of the bridge in the tag as well as in need to match the name of the bridge device configured using netplan:

<network>
  <name>br0</name>
  <bridge name='br0'/>
  <forward mode="bridge"/>
</network>

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.