DEFAULT_ACCESS_LOG_FORMAT

ferron::util::log_placeholders

Constant DEFAULT_ACCESS_LOG_FORMAT 

Source 
const DEFAULT_ACCESS_LOG_FORMAT: &str = "{client_ip} - {auth_user} [{timestamp}] \"{method} {path_and_query} {version}\" \
   {status_code} {content_length} \"{header:Referer}\" \"{header:User-Agent}\"";