feature: support use of bridges via veth pairs for openvswitch data port configuration

[Matt Rae]

When configuring vlan provider networks in neutron, it is currently required to set data-port=br-ex:(some unconfigured interface).

Some users don't have an additional interface to leave unconfigured to use as data-port.

When using neutorn vlan provider networks which are trunked to the management interface, we found that the neutron-openvswitch charm runs 'ovs-vsctl add-port br-ex bond0', but that command fails with 'device busy'

We found the following solution which creates a veth pair between veth-br-bond0 and veth-tenant which allows both containers to br-bond0 but also neutron vlan provider networks to function.

on each compute node
# create veth pair between br-bond0 and veth-tenant
ip l add name veth-br-bond0 type veth peer name veth-tenant

# set mtu if needed on veth interfaces and turn up
#ip l set dev veth-br-bond0 mtu 9000
#ip l set dev veth-tenant mtu 9000
ip l set dev veth-br-bond0 up
ip l set dev veth-tenant up

# add br-bond0 as master for veth-br-bond0
ip l set veth-br-bond0 master br-bond0

juju set neutron-openvswitch data-port="br-ex:veth-tenant"

Should something like this be added to the neutron-openvswitch charm to allow neutron vlan provider networks on the management interface?

[Aymen Frikha (aym-frikha)]

I also tested it with flat provider network, and it seems that we have the same issue. The solution provided by Matt works for me also. It seems that the OVS bridge can't use an interface which is already connected to a linuxbridge.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/392212

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/392212
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-openvswitch/commit/?id=f832f1073d47a430111c59563962922dfe37a0a5
Submitter: Jenkins
Branch: master

commit f832f1073d47a430111c59563962922dfe37a0a5
Author: Matt Rae <email address hidden>
Date: Thu Mar 16 01:32:42 2017 -0700

    Add support of a linuxbridge bridge in data-port config

    When configuring data-port parameter with "ovs-bridge:linuxbridge"
    a veth pair will be created to connect these two bridges. Name of
    these virtual interfaces will be "veth-ovsbridge_name" and
    "veth-linuxbridge_name".

    Problem: When deploying neutron-openvswitch charm on a node contain
    only one interface, we are not able to connect an ovs Bridge to
    the physical interface because it is assigned to juju Bridge.

    Change-Id: I5be72b9cc5948f5f791d522d1b46fd27e7303613
    Closes-Bug:#1635067

[Jill Rouleau (jillrouleau)]

sorry, mouse flailed while reading the bug and accidentally changed status. Undid that.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/562982

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/562982
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-gateway/commit/?id=2441950f44437d26e329899f5cc28a6065ec822a
Submitter: Zuul
Branch: master

commit 2441950f44437d26e329899f5cc28a6065ec822a
Author: James Page <email address hidden>
Date: Fri Apr 20 09:18:46 2018 +0100

    Add support for use of bridges for data ports

    Inline with neutron-openvswitch add support for use of existing
    linuxbridge's when wiring openvswitch bridges to underlying
    network devices.

    Change-Id: I24281e8c31d9a140dfdaff308e6e99d3ce162fef
    Closes-Bug: 1635067

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/18.02
Review: https://review.openstack.org/564260

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/564260
Committed: https://git.openstack.org/cgit/openstack/charm-neutron-gateway/commit/?id=de4c97e8bb1e672dbd36d56d28bc0c2571c1ecad
Submitter: Zuul
Branch: stable/18.02

commit de4c97e8bb1e672dbd36d56d28bc0c2571c1ecad
Author: James Page <email address hidden>
Date: Fri Apr 20 09:18:46 2018 +0100

    Add support for use of bridges for data ports

    Inline with neutron-openvswitch add support for use of existing
    linuxbridge's when wiring openvswitch bridges to underlying
    network devices.

    Change-Id: I24281e8c31d9a140dfdaff308e6e99d3ce162fef
    Closes-Bug: 1635067
    (cherry picked from commit 2441950f44437d26e329899f5cc28a6065ec822a)