Add support for Open vSwitch bridges used in libvirt interfaces to Koan

[rasschaert]

I replaced my Linux bridge with Open vSwitch because of some technical limitations of Linux bridges.

I was able to configure libvirt to deal with this, following these instructions.

Note that I also removed and blacklisted the bridge kernel module, as well as the bridge-utils package containing the brctl command because calling the brctl command loads the bridge kernel module which breaks Open vSwitch.
In other words: classic Linux bridging is no longer in any way available on my machine.

This works when manually creating virtual machines with virt-install, when using the following network options:

virt-install --network network=br0

When I create a machine with Koan, however, it is created with:

virt-install --network bridge=br0

Which fails with the following error:

ERROR    Unable to add bridge br0 port vnet1: Operation not supported
Domain installation does not appear to have been successful.

Koan does not appear to support passing this option to virt-install at the moment.

My technical environment: CentOS 6.4 as both virtual guest and host OS. KVM virtualization, Open vSwitch package procured from the RDO repository.

[jmaas]

It's something where i want Cobbler to go; more aligned with Cloud infrastructure. So vswitch support is very much a requirement. This is something i have in mind for Cobbler3, so that will take a while. If you have concrete suggestions (or even better: patches) in the meantime please let us know.

[rasschaert]

For now I just hacked in a quick fix for me so that my machines can boot.

sed -i 's/--network bridge/--network network/' /usr/lib/python2.6/site-packages/koan/virtinstall.py

I don't really known the insides of Cobbler well enough to patch the network device discovery.

[jmaas]

Btw, what version of Cobbler/Koan are you using?

[rasschaert]

I'm using 2.4.0, the version that's currently packaged in EPEL for EL 6.