This is how to set the setgid flag with Ansible. Tested with Ansible version 2.4.
```yaml
- name: Create directories and set setguid
file:
path: "{{item}}"
state: directory
owner: www-data
group: www-data
# NOTE: 2 = setguid flag. The prefix 0 is required by Ansible
mode: 02770
recurse: true
with_items:
- /var/www/
become: true
```
## Reference
Setting the setgid permission on a directory ("chmod g+s") causes new files and subdirectories created within it to inherit its group ID, rather than the primary group ID of the user who created the file (the owner ID is never affected, only the group ID).
See https://en.wikipedia.org/wiki/Setuid