Check for presence of template indicator and if found, perform
    variable substition on script based on template type, returning
    script.

def substitute(script, submap):

    """Check for presence of template indicator and if found, perform
    variable substition on script based on template type, returning
    script."""

    match = config.TEMPLATE_RE.search(script)
    if match:
        template_type = match.groupdict()['type']
        try:
            return config.TEMPLATE_TYPEMAP[template_type](script, submap)
        except KeyError:
            logger.error('Unsupported template type: %s' % template_type)
            raise
    return script