NodeJS ExpressJS - how to log errors for the production server?

Question

How can I log any errors from ExpressJS apps into a file?

I know I can log a Slim framework easily with monolog:

$app->get(\'/tickets\', function          


        

Answer 1

winston is a popular library for logging.

You can transport all logs to one file or keep different files for error, debug and info logs.

Example:

  var winston = require('winston');

  var logger = new winston.Logger({
    level: 'error',
    transports: [
      new (winston.transports.File)({ filename: 'error.log' })
    ]
  });

In the code:

logger.log('error', 'test error message %s', 'my string');

You can also use winston daily rotate file with winston to rotate your log files based on size or date.