Add a router to the lb-mgmt-net for slaac

Neutron now needs to have a router attached to the subnet to provide
the router advertisement messages needed for slaac address
configuration.
This patch adds this router to the lb-mgmt-network, allowing
the amphora instances to configure an IPv6 address.

Change-Id: I638c5c8baf1d76365fff2c99ded9c6b310348710

devstack/plugin.sh

@@ -502,6 +502,9 @@ function build_mgmt_network {
     openstack network create lb-mgmt-net
     if [ $SERVICE_IP_VERSION == '6' ] ; then
         openstack subnet create --subnet-range $OCTAVIA_MGMT_SUBNET_IPV6 --allocation-pool start=$OCTAVIA_MGMT_SUBNET_IPV6_START,end=$OCTAVIA_MGMT_SUBNET_IPV6_END --network lb-mgmt-net --ip-version 6 --ipv6-address-mode slaac --ipv6-ra-mode slaac lb-mgmt-subnet
+        # SLAAC needs a router on the subnet to advertise the prefix.
+        openstack router create lb-mgmt-router
+        openstack router add subnet lb-mgmt-router lb-mgmt-subnet
     else
         openstack subnet create --subnet-range $OCTAVIA_MGMT_SUBNET --allocation-pool start=$OCTAVIA_MGMT_SUBNET_START,end=$OCTAVIA_MGMT_SUBNET_END --network lb-mgmt-net lb-mgmt-subnet
     fi

zuul.d/projects.yaml

@@ -52,6 +52,9 @@
         - octavia-v2-dsvm-scenario-two-node:
             irrelevant-files: *irrelevant-files
             voting: false
+        - octavia-v2-dsvm-scenario-ipv6-only:
+            irrelevant-files: *irrelevant-files
+            voting: false
         - octavia-v2-dsvm-scenario-amphora-v2:
             irrelevant-files: *irrelevant-files
             voting: false