1113 fix ec2 subnet tags

lib/ansible/modules/cloud/amazon/ec2_vpc.py

@@ -46,9 +46,10 @@ options:
     choices: [ "yes", "no" ]
   subnets:
     description:
-      - 'A dictionary array of subnets to add of the form: { cidr: ..., az: ... , resource_tags: ... }. Where az is the desired availability zone of the subnet, but it is not required. Tags (i.e.: resource_tags) is also optional and use dictionary form: { "Environment":"Dev", "Tier":"Web", ...}. All VPC subnets not in this list will be removed. As of 1.8, if the subnets parameter is not specified, no existing subnets will be modified.'
+      - 'A dictionary array of subnets to add of the form: { cidr: ..., az: ... , resource_tags: ... }. Where az is the desired availability zone of the subnet, but it is not required. Tags (i.e.: resource_tags) is also optional and use dictionary form: { "Environment":"Dev", "Tier":"Web", ...}. All VPC subnets not in this list will be removed as well. As of 1.8, if the subnets parameter is not specified, no existing subnets will be modified.'
     required: false
     default: null
+    resource_tags: See resource_tags for VPC below. The main difference is subnet tags not specified here will be deleted. 
   vpc_id:
     description:
       - A VPC id to terminate when state=absent
@@ -404,9 +405,39 @@ def create_vpc(module, vpc_conn):
         # First add all new subnets
         for subnet in subnets:
             add_subnet = True
+            subnet_tags_current = True
+            new_subnet_tags = subnet.get('resource_tags', None)
+            subnet_tags_delete = []
+            
             for csn in current_subnets:
                 if subnet['cidr'] == csn.cidr_block:
                     add_subnet = False
+
+                # Check if AWS subnet tags are in playbook subnet tags
+                subnet_tags_extra = (set(csn.tags.items()).issubset(set(new_subnet_tags.items())))
+                # Check if subnet tags in playbook are in AWS subnet tags 
+                subnet_tags_current = (set(new_subnet_tags.items()).issubset(set(csn.tags.items())))
+                if subnet_tags_extra is False:
+                    try:
+                        for item in csn.tags.items():
+                            if item not in new_subnet_tags.items():
+                                subnet_tags_delete.append(item)
+
+                        subnet_tags_delete = [key[0] for key in subnet_tags_delete]
+                        delete_subnet_tag = vpc_conn.delete_tags(csn.id, subnet_tags_delete)
+                        changed = True
+                    except EC2ResponseError, e:
+                        module.fail_json(msg='Unable to delete resource tag, error {0}'.format(e))
+                # Add new subnet tags if not current
+                subnet_tags_current = (set(new_subnet_tags.items()).issubset(set(csn.tags.items())))
+                if subnet_tags_current is not True:
+                    try:
+                        changed = True
+                        create_subnet_tag = vpc_conn.create_tags(csn.id, new_subnet_tags)
+
+                    except EC2ResponseError, e:
+                        module.fail_json(msg='Unable to create resource tag, error: {0}'.format(e))
+
             if add_subnet:
                 try:
                     new_subnet = vpc_conn.create_subnet(vpc.id, subnet['cidr'], subnet.get('az', None))