ovn: make DVR work on VLAN tenant networks

In order for DVR to work on VLAN tenant networks we need to configure
external_ids:ovn-chassis-mac-mappings with per node generated MAC [1]
on computes [1].

[1]: 1fed74cfc1

Co-Authored-By: Bartosz Bezak <bartosz@stackhpc.com>

Depends-On: https://review.opendev.org/c/openstack/neutron/+/782250
Change-Id: I3a3ccde5b9ef2afb4c3e9206f13827687880cb57

ansible/roles/ovn/defaults/main.yml

@@ -88,5 +88,7 @@ ovn_sb_db_extra_volumes: "{{ ovn_extra_volumes }}"
 #####
 # OVN
 #####
+# Base MAC for ovn-chassis-mac-mappings generation
+ovn_base_mac: "52:54:00"
 # Configure OVN remote probe interval time in ms
 ovn_remote_probe_interval: "60000"

ansible/roles/ovn/tasks/bootstrap.yml

@@ -12,6 +12,7 @@
 - name: Configure OVN in OVSDB
   vars:
     ovn_mappings: "{% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index0 + 1 }}:{{ bridge }}{% if not loop.last %},{% endif %}{% endfor %}"
+    ovn_macs: "{% for bridge in neutron_bridge_name.split(',') %}physnet{{ loop.index0 + 1 }}:{{ ovn_base_mac | random_mac(seed=inventory_hostname+bridge) }}{% if not loop.last %},{% endif %}{% endfor %}"
     ovn_cms_opts: "{{ 'enable-chassis-as-gw' if inventory_hostname in groups['ovn-controller-network'] else '' }}"
   become: true
   kolla_toolbox:
@@ -30,4 +31,5 @@
     - { name: ovn-remote, value: "{{ ovn_sb_connection }}" }
     - { name: ovn-remote-probe-interval, value: "{{ ovn_remote_probe_interval }}" }
     - { name: ovn-bridge-mappings, value: "{{ ovn_mappings }}", state: "{{ 'present' if (inventory_hostname in groups['ovn-controller-network'] or computes_need_external_bridge | bool) else 'absent' }}" }
+    - { name: ovn-chassis-mac-mappings, value: "{{ ovn_macs }}", state: "{{ 'present' if inventory_hostname in groups['ovn-controller-compute'] else 'absent' }}" }
     - { name: ovn-cms-options, value: "{{ ovn_cms_opts }}", state: "{{ 'present' if ovn_cms_opts != '' else 'absent' }}" }

releasenotes/notes/ovn_dvr_vlan-f36a6868cfd4776e.yaml

@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    OVN deployment will now configure ``external_ids:ovn-chassis-mac-mappings``
+    to make DVR work on VLAN tenant networks.