Add TCP listener on OVSDB

Per [1], Nova expects the local OVSDB server to listen to TCP port 6640
on localhost. This patch adds the default var neutron_ovsdb_manager and
creates a TCP listener on the OVN controller/compute, if needed.

[1]: https://bugs.launchpad.net/charm-nova-compute/+bug/1852200

Change-Id: Id9573af6a0d533e74af6cd4cf9c32e4088fa5e79

defaults/main.yml

@@ -445,6 +445,7 @@ neutron_ovn_northd_service_name: ovn-northd
 neutron_ovn_controller_service_name: ovn-controller
 neutron_ovn_l3_scheduler: leastloaded
 neutron_ovn_ip: "{{ internal_lb_vip_address }}"
+neutron_ovsdb_manager: ptcp:6640:127.0.0.1
 
 # Install Openvswitch without NSH support
 ovs_nsh_support: False

tasks/providers/setup_ovs_ovn.yml

@@ -57,6 +57,19 @@
   when:
     - neutron_services['neutron-ovn-controller']['group'] in group_names
 
+# Create an ovsdb manager for Nova (os-vif)
+- name: Register existing OVSDB Manager(s)
+  command: ovs-vsctl get-manager
+  register: existing_ovsdb_manager
+  when:
+    - neutron_services['neutron-ovn-controller']['group'] in group_names
+
+- name: Create OVSDB Manager
+  command: ovs-vsctl --id @manager create Manager "target=\"{{ neutron_ovsdb_manager }}\"" -- add Open_vSwitch . manager_options @manager
+  when:
+    - neutron_services['neutron-ovn-controller']['group'] in group_names
+    - neutron_ovsdb_manager not in existing_ovsdb_manager.stdout_lines
+
 - name: Setup Network Provider Bridges
   openvswitch_bridge:
     bridge: "{{ bridge_mapping.split(':')[1] }}"