azure subnet's properties should not be changed if parameter set to None (route table, nsg...) (#54019)

lib/ansible/modules/cloud/azure/azure_rm_subnet.py

@@ -36,7 +36,6 @@ options:
         description:
             - CIDR defining the IPv4 address space of the subnet. Must be valid within the context of the
               virtual network.
-        required: true
         aliases:
             - address_prefix
     security_group:
@@ -205,10 +204,6 @@ class AzureRMSubnet(AzureRMModuleBase):
             )
         )
 
-        required_if = [
-            ('state', 'present', ['address_prefix_cidr'])
-        ]
-
         self.results = dict(
             changed=False,
             state=dict()
@@ -224,8 +219,7 @@ class AzureRMSubnet(AzureRMModuleBase):
         self.service_endpoints = None
 
         super(AzureRMSubnet, self).__init__(self.module_arg_spec,
-                                            supports_check_mode=True,
-                                            required_if=required_if)
+                                            supports_check_mode=True)
 
     def exec_module(self, **kwargs):
 
@@ -235,9 +229,10 @@ class AzureRMSubnet(AzureRMModuleBase):
         for key in self.module_arg_spec:
             setattr(self, key, kwargs[key])
 
-        if self.state == 'present' and not CIDR_PATTERN.match(self.address_prefix_cidr):
+        if self.address_prefix_cidr and not CIDR_PATTERN.match(self.address_prefix_cidr):
             self.fail("Invalid address_prefix_cidr value {0}".format(self.address_prefix_cidr))
 
+        nsg = dict()
         if self.security_group:
             nsg = self.parse_nsg()
 
@@ -262,19 +257,17 @@ class AzureRMSubnet(AzureRMModuleBase):
             results = subnet_to_dict(subnet)
 
             if self.state == 'present':
-                if self.address_prefix_cidr:
-                    if results['address_prefix'] != self.address_prefix_cidr:
+                if self.address_prefix_cidr and results['address_prefix'] != self.address_prefix_cidr:
                     self.log("CHANGED: subnet {0} address_prefix_cidr".format(self.name))
                     changed = True
                     results['address_prefix'] = self.address_prefix_cidr
 
-                if nsg:
-                    if results['network_security_group'].get('id') != nsg.get('id'):
+                if self.security_group is not None and results['network_security_group'].get('id') != nsg.get('id'):
                     self.log("CHANGED: subnet {0} network security group".format(self.name))
                     changed = True
                     results['network_security_group']['id'] = nsg.get('id')
                     results['network_security_group']['name'] = nsg.get('name')
-                if self.route_table != results['route_table'].get('id'):
+                if self.route_table is not None and self.route_table != results['route_table'].get('id'):
                     changed = True
                     results['route_table']['id'] = self.route_table
                     self.log("CHANGED: subnet {0} route_table to {1}".format(self.name, route_table.get('name')))
@@ -310,6 +303,8 @@ class AzureRMSubnet(AzureRMModuleBase):
             if self.state == 'present' and changed:
                 if not subnet:
                     # create new subnet
+                    if not self.address_prefix_cidr:
+                        self.fail('address_prefix_cidr is not set')
                     self.log('Creating subnet {0}'.format(self.name))
                     subnet = self.network_models.Subnet(
                         address_prefix=self.address_prefix_cidr
@@ -324,13 +319,13 @@ class AzureRMSubnet(AzureRMModuleBase):
                     subnet = self.network_models.Subnet(
                         address_prefix=results['address_prefix']
                     )
-                    if results['network_security_group'].get('id'):
+                    if results['network_security_group'].get('id') is not None:
                         subnet.network_security_group = self.network_models.NetworkSecurityGroup(id=results['network_security_group'].get('id'))
-                    if self.route_table:
-                        subnet.route_table = self.network_models.RouteTable(id=self.route_table)
+                    if results['route_table'].get('id') is not None:
+                        subnet.route_table = self.network_models.RouteTable(id=results['route_table'].get('id'))
 
-                    if self.service_endpoints:
-                        subnet.service_endpoints = self.service_endpoints
+                    if results.get('service_endpoints') is not None:
+                        subnet.service_endpoints = results['service_endpoints']
 
                 self.results['state'] = self.create_or_update_subnet(subnet)
             elif self.state == 'absent' and changed:

test/integration/targets/azure_rm_subnet/tasks/main.yml

@@ -48,6 +48,16 @@
 - assert:
     that: output.changed
 
+- name: Add the subnet back (idempontent)
+  azure_rm_subnet:
+    name: foobar
+    virtual_network_name: My_Virtual_Network
+    resource_group: "{{ resource_group }}"
+  register: output
+
+- assert:
+    that: not output.changed
+
 - name: Create network security group
   azure_rm_securitygroup:
     name: secgroupfoo
@@ -77,7 +87,6 @@
     virtual_network_name: My_Virtual_Network
     resource_group: "{{ resource_group }}"
     address_prefix_cidr: "10.1.0.0/16"
-    security_group: secgroupfoo
     service_endpoints:
       - service: Microsoft.Sql
         locations:
@@ -123,7 +132,6 @@
     virtual_network_name: My_Virtual_Network
     resource_group: "{{ resource_group }}"
     address_prefix_cidr: "10.1.0.0/16"
-    route_table: "{{ route_table.id }}"
     security_group: "{{ nsg.state.id }}"
     tags:
        testing: testing