Allow networks to be updated

Neutron will allow you to update certain properties of the network after
creation. This change modifies the ansible code to perform an update
call if it detects that any updatable properties have been changed. If
you attempt to change a property that cannot be updated, the module will
fail. This gives you confidence that the ansible configuration matches
the state of the network in OpenStack. If we did not fail in this way,
you might think you have updated the network, but in reality those
changes would be silently ignored. Prior to this change, the only way to
update properties of a network was to delete it and then recreate.

Story: 2010024
Task: 45262
Change-Id: I4af2b50f207f349b58c63e0a4e92816ada0847fd

ci/roles/network/defaults/main.yml

@@ -31,5 +31,6 @@ mtu: 1250
 network_external: false
 network_name: shade_network
 network_name_newparams: newparams_network
+network_name_updates: update_network
 network_shared: false
 port_security_enabled: false

ci/roles/network/tasks/main.yml

@@ -105,3 +105,66 @@
   assert:
     that:
       - result_nonet.networks == []
+
+- name: Create network - updates
+  openstack.cloud.network:
+     cloud: "{{ cloud }}"
+     name: "{{ network_name_updates }}"
+     state: present
+     shared: "{{ network_shared }}"
+     external: "{{ network_external }}"
+     mtu: "{{ mtu }}"
+     port_security_enabled: "{{ port_security_enabled }}"
+  register: result_create_nw_for_updates
+
+- name: Update network - update failure
+  openstack.cloud.network:
+     cloud: "{{ cloud }}"
+     name: "{{ network_name_updates }}"
+     state: present
+     shared: "{{ network_shared }}"
+     external: "{{ network_external }}"
+     mtu: "{{ mtu }}"
+     port_security_enabled: "{{ port_security_enabled }}"
+     # You cannot update this property.
+     provider_physical_network: cannot_be_updated
+  ignore_errors: true
+  register: result_nw_update_failure
+
+- name: Verify networks info - update fail
+  assert:
+    that:
+      - result_nw_update_failure is failed
+
+- name: Update network - update success
+  openstack.cloud.network:
+     cloud: "{{ cloud }}"
+     name: "{{ network_name_updates }}"
+     state: present
+     shared: "{{ network_shared }}"
+     external: "{{ network_external }}"
+     # NOTE: This property should be updated
+     mtu: "{{ mtu - 50 }}"
+     # NOTE: This property should be updated
+     port_security_enabled: "{{ not port_security_enabled }}"
+  register: result_nw_update_success
+
+- name: Gather networks info - updates
+  openstack.cloud.networks_info:
+     cloud: "{{ cloud }}"
+     name: "{{ network_name_updates }}"
+  register: result_network_updates_info
+
+- name: Verify networks info - update success
+  assert:
+    that:
+      - result_nw_update_success is changed
+      - result_network_updates_info.networks.0.name == network_name_updates
+      - result_network_updates_info.networks.0.mtu == mtu - 50
+      - result_network_updates_info.networks.0['is_port_security_enabled'] == (not port_security_enabled)
+
+- name: Delete network - updates
+  openstack.cloud.network:
+     cloud: "{{ cloud }}"
+     name: "{{ network_name_updates }}"
+     state: absent

plugins/modules/network.py

@@ -234,27 +234,57 @@ class NetworkModule(OpenStackModule):
         net = self.conn.network.find_network(name, **net_kwargs)
 
         if state == 'present':
-            if not net:
-                if provider_physical_network:
-                    kwargs['provider_physical_network'] = provider_physical_network
-                if provider_network_type:
-                    kwargs['provider_network_type'] = provider_network_type
-                if provider_segmentation_id:
-                    kwargs['provider_segmentation_id'] = provider_segmentation_id
+            if provider_physical_network:
+                kwargs['provider_physical_network'] = provider_physical_network
+            if provider_network_type:
+                kwargs['provider_network_type'] = provider_network_type
+            if provider_segmentation_id:
+                kwargs['provider_segmentation_id'] = provider_segmentation_id
 
-                if project_id is not None:
-                    kwargs['project_id'] = project_id
-                net = self.conn.network.create_network(name=name,
-                                                       shared=shared,
-                                                       admin_state_up=admin_state_up,
-                                                       is_router_external=external,
-                                                       **kwargs)
+            if project_id is not None:
+                kwargs['project_id'] = project_id
+
+            kwargs["shared"] = shared
+            kwargs["admin_state_up"] = admin_state_up
+            kwargs["is_router_external"] = external
+
+            if not net:
+                net = self.conn.network.create_network(name=name, **kwargs)
                 changed = True
-                net = net.to_dict(computed=False)
             else:
                 changed = False
-            self.exit(changed=changed, network=net, id=net['id'])
+                update_kwargs = {}
 
+                # Check we are not trying to update an properties that cannot be modified
+                non_updatables = [
+                    "provider_network_type",
+                    "provider_physical_network",
+                ]
+                for arg in non_updatables:
+                    if arg in kwargs and kwargs[arg] != net[arg]:
+                        self.fail_json(
+                            msg="The following parameters cannot be updated: "
+                                "%s. You will need to use state: absent and "
+                                "recreate." % ', '.join(non_updatables)
+                        )
+
+                # Filter args to update call to the ones that have been modifed
+                # and are updatable. Adapted from:
+                # https://github.com/openstack/openstacksdk/blob/1ce15c9a8758b4d978eb5239bae100ddc13c8875/openstack/cloud/_network.py#L559-L561
+                for arg in ["shared", "admin_state_up", "is_router_external",
+                            "mtu", "port_security_enabled", "dns_domain",
+                            "provider_segmentation_id"]:
+                    if arg in kwargs and kwargs[arg] != net[arg]:
+                        update_kwargs[arg] = kwargs[arg]
+
+                if update_kwargs:
+                    net = self.conn.network.update_network(
+                        net.id, **update_kwargs
+                    )
+                    changed = True
+
+            net = net.to_dict(computed=False)
+            self.exit(changed=changed, network=net, id=net['id'])
         elif state == 'absent':
             if not net:
                 self.exit(changed=False)