Return the contents of an interface script

    CLI Example:

    .. code-block:: bash

        salt '*' ip.get_interface eth0

def get_interface(iface):
    '''
    Return the contents of an interface script

    CLI Example:

    .. code-block:: bash

        salt '*' ip.get_interface eth0
    '''

    adapters = _parse_interfaces()
    if iface in adapters:
        try:
            if iface == 'source':
                template = JINJA.get_template('debian_source.jinja')
            else:
                template = JINJA.get_template('debian_eth.jinja')
        except jinja2.exceptions.TemplateNotFound:
            log.error('Could not load template debian_eth.jinja')
            return ''

        ifcfg = template.render({'name': iface, 'data': adapters[iface]})

        # ensure lines in list end with newline, so difflib works
        return [item + '\n' for item in ifcfg.split('\n')]
    else:
        return []