version: '0.10'
services:
- service:
  - name: test
    file:
    - file_type: variable
      source: mailname
      variable: var
      text: file_name
variables:
- variable:
  - name: file_name
    type: filename
    value:
    - text: /etc/mailname
  - name: var
    type: string
    value:
    - text: mailname