Event listener for HTTP server "listening" event.
function onListening () {
        let addr = server.address(),
            bind = typeof addr === 'string'
          ? 'pipe ' + addr
          : 'port ' + addr.port;
        we.log.info('Run in '+we.env+' enviroment and listening on ' + bind);

        if (process.send) {
          process.send('ready');
        }
      }