openvswitch: add external-ids:hostname

It's been introduced in [1] and seems to be used by ovn-controller.

[1]: https://patchwork.ozlabs.org/project/openvswitch/patch/1458866450-1967-1-git-send-email-russell@ovn.org/

Change-Id: I90e91f2923d58eb3c70e8d6efdc4e1212fbdc14f

ansible/roles/openvswitch/defaults/main.yml

@@ -103,4 +103,5 @@ openvswitch_ovs_vsctl_wrapper_enabled: false
 #############
 
 openvswitch_system_id: "{{ ansible_facts.hostname }}"
+openvswitch_hostname: "{{ ansible_facts.hostname }}"
 openvswitch_hw_offload: "no"

ansible/roles/openvswitch/tasks/post-config.yml

@@ -15,6 +15,7 @@
       state: "{{ item.state | default('present') }}"
   loop:
     - { col: "external_ids", name: "system-id", value: "{{ openvswitch_system_id }}" }
+    - { col: "external_ids", name: "hostname", value: "{{ openvswitch_hostname }}" }
     - { col: "other_config", name: "hw-offload", value: true, state: "{{ 'present' if openvswitch_hw_offload | bool else 'absent' }}" }
 
 - name: Ensuring OVS bridge is properly setup