Description of problem: OSP 10 is the first release to fully support DVR (it is no longer considered Tech Preview). The OSP-Director documentation should instruct users on creating custom NIC config templates for the Compute nodes when DVR is enabled.

In order for DVR to function, the Controller and Compute nodes will have to share at least one external bridge. The bridge(s) will be used to host the external network(s) on each Compute node for Floating IP support, as well as on the Controllers for general SNAT support.


Version-Release number of selected component (if applicable): OSP 10 GA

Actual results: The custom changes required are not currently documented. 


Expected results: The requirements for the external bridge should be documented.

Additional info: The sample templates which create a bridge using a parameter for bridge_name (which defaults to "br-ex") will already support DVR. The existing sample templates for single NIC and bonded configurations already use this bridge. The multiple NICs template does not include that bridge on the Compute nodes. Most customers will create custom NIC config templates, and we need to document how to properly use the external bridge for custom templates.

Here is some example documentation text:

OSP-Director 10 now includes full support for DVR (Distributed Virtual Routing). This improves performance by localizing the Neutron L3 routing on each Compute node as well as the Controllers. In order for DVR to function, the Controller and Compute nodes must have the same external bridge(s) configured.

To use DVR, the Compute nodes should have the same external bridge configuration as the Controllers. The "bridge_name" parameter in the sample NIC config templates will be replaced with the default bridge name "br-ex", but any bridge name may be used as long as the Compute and Controllers match, and the Neutron bridge mappings include the correct bridge name(s). The Compute nodes should not typically have an interface or IP address configured on the External network; only the external bridge is required.

Here is an example configuration for an external bridge on a single interface on a compute node:

            -
              type: ovs_bridge
              name: {get_input: bridge_name}
              use_dhcp: false
              members:
                -
                  type: interface
                  name: nic2
                  # force the MAC address of the bridge to this interface
                  primary: true