Ansible / Pass an array through extra-vars

Let's imagine we want to provision a machine with Nginx server. server_name allows to specify several domain names separated by a space. Here is a simple Ansible script that reads an array of domains from extra-vars provided on the command line and put them as a value of server_name.

---
- tasks:
    - template: src=nginx-vhost.conf dest=/etc/nginx/sites-available/foo.com

Here is nginx-vhost.con

server {
    listen 80;
    server_name {{ domains|join(' ') }};
    root /srv/www/boo.com/public
}

Put both files in the same directory and run it through ansible-playbook and pass a proper JSON to --extra-vars parameter as below:

ansible-playbook -i hosts playbook.yml --extra-vars '{"domains": ["boo.com", "foo.com"]}'

In Ansible >= 1.3 extra-vars can be also loaded from a JSON or YAML file with the @ syntax:

--extra-vars "@some_file.json"

As a result you should have the following file generated under /etc/nginx/sites-available/foo.com

server {¬
    listen 80;
    server_name boo.com foo.com;
    root /srv/www/boo.com/public
}