How to specify hosts in variables for stuff like access control lists

gistfile1.txt

$ ansible-playbook -i hosts -c local access.yaml 

PLAY [all] ******************************************************************** 

GATHERING FACTS *************************************************************** 
ok: [127.0.0.1]

TASK: [template src=./access.j2 dest=./access.conf] *************************** 
changed: [127.0.0.1]

PLAY RECAP ******************************************************************** 
127.0.0.1                  : ok=2    changed=1    unreachable=0    failed=0   

$ cat access.conf 
<Directory "/var/www/html/">
   order allow,deny 
   allow from 192.168.1.1
   allow from 10.0.0.0/8
</Directory>
$ cat access.j2 
<Directory "/var/www/html/">
   order allow,deny 
{% for h in hosts %}
   allow from {{ h }}
{% endfor %}
</Directory>
$ cat access.yaml 
---
- hosts: all

  vars:
    hosts:
      - 192.168.1.1
      - 10.0.0.0/8
  tasks:
      - template: src=./access.j2 dest=./access.conf