#salt/nginx/top.sls
{% for vh in grains['vhosts'] %} # [site1]
{% set vhost = salt['pillar.get']('vhosts:{{ vh }}', 'unkn')  %}
{{ vh }}:
  cmd.run:
    - name: /bin/echo "Make config for {{ vhost['server_name'] }}"
{% endfor %}

#pillar/vhosts.sls
vhosts:
  site1:
    server_name: site1.example.com
  site2:
    server_name: site2.domain.com