Support ocata release of ironic

In the Ocata release, the physical_network field of ports did not exist.
The safest thing to do is to simply ignore it in this case.

It is also possible for the local_link_connection fields to not have switch_id,
switch_info or port_id attributes, so we now use .get(attr) to avoid an
attribute lookup error.

Change-Id: Ib4829dbd89fcedc121f493d6af76702421b399f7
TrivialFix

ansible/roles/ironic-enrolment/tasks/main.yml

@@ -26,6 +26,20 @@
   until: result is success
   retries: 3
 
+- name: Detect ironic API version
+  command: >-
+    {{ ironic_virtualenv_path }}/bin/openstack
+    --os-baremetal-api-version 1.34
+    baremetal node list
+  register: api_version_result
+  changed_when: false
+  failed_when: false
+
+# This is used in port.yml.
+- name: Set a fact about whether Ironic supports physical network awareness
+  set_fact:
+    supports_port_physnet: "{{ api_version_result.rc == 0 }}"
+
 # This command will return the UUIDs, regardless of whether
 # ironic_deploy_kernel and ironic_deploy_ramdisk are image UUIDs or names.
 - name: Get OpenStack deployment image UUIDs

ansible/roles/ironic-enrolment/tasks/port.yml

@@ -40,12 +40,14 @@
   command: >-
     '{{ ironic_virtualenv_path }}/bin/openstack' baremetal port set
       {{ uuid.stdout }}
+      {% if supports_port_physnet %}
       --physical-network '{{ physnet }}'
+      {% endif %}
       --local-link-connection switch_id='{{ switch_id }}'
       --local-link-connection switch_info='{{ bridge }}'
       --local-link-connection port_id='{{ port_id }}'
   when: >-
-    port_attributes.physical_network != physnet or
-    port_attributes.local_link_connection.switch_id != switch_id or
-    port_attributes.local_link_connection.switch_info != switch_info or
-    port_attributes.local_link_connection.port_id != port_id
+    (supports_port_physnet and port_attributes.physical_network != physnet) or
+    port_attributes.local_link_connection.get('switch_id') != switch_id or
+    port_attributes.local_link_connection.get('switch_info') != switch_info or
+    port_attributes.local_link_connection.get('port_id') != port_id