Automate OVS bridge creation for multiple mappings
Allows the definition of the global variable OVS_BRIDGE_MAPPINGS (e.g.
in local.conf) to automatically trigger the creation of multiple OVS
bridges. For example:
OVS_BRIDGE_MAPPINGS=physnet1:br-br-enp0s20f1,physnet2:br-enp0s20f2
should automatically yield the creation of two bridges, respectively
associated to the two physical networks declared,
by simply running DevStack with the OVS agent enabled.
Documentation has also been added to doc/source/guides/neutron.rst.
Change-Id: I79dc0213c9d70ba628621c4c0f65481783590085
Closes-Bug: #1535835
diff --git a/doc/source/guides/neutron.rst b/doc/source/guides/neutron.rst
index 1e20d7f..be85b63 100644
--- a/doc/source/guides/neutron.rst
+++ b/doc/source/guides/neutron.rst
@@ -535,3 +535,19 @@
LB_PHYSICAL_INTERFACE=eth0
PUBLIC_PHYSICAL_NETWORK=default
LB_INTERFACE_MAPPINGS=default:eth0
+
+Creating specific OVS bridges for physical networks
+---------------------------------------------------
+
+When using the Open vSwitch ML2 mechanism driver, it is possible to
+have multiple Open vSwitch bridges meant for physical networking be
+automatically created by setting the ``OVS_BRIDGE_MAPPINGS`` to a list of
+physical network to bridge name associations with the following syntax:
+
+::
+ OVS_BRIDGE_MAPPINGS=net1name:bridge1name,net2name:bridge2name,<...>
+
+Also, ``OVS_BRIDGE_MAPPINGS`` has precedence over ``PHYSICAL_NETWORK`` and
+``OVS_PHYSICAL_BRIDGE``, meaning that if the former is set, the latter
+ones will be ignored. When ``OVS_BRIDGE_MAPPINGS`` is not set, the other
+variables will still be evaluated.