Winston: how to rotate logs

Question

How can I rotate logs when using Winston to handle logging for node.js. That is, how can I create a new file for each day the app runs?

    var logger = new (winston.Logger)({        transports: [           new (winston.transports.Console)(),           new (winston.transports.File)({ filename: '2012-07-09.log' })       ] });  logger.log('info', 'Test Log Message', { anything: 'This is metadata' }); 

Answer 1

winston author and maintainer here.

Logging to a new file everyday is currently an open feature request: https://github.com/flatiron/winston/issues/10. Would love to see someone implement it.

That said, there are other options:

1. The File transport accepts a maxsize option which will rotate the logfile when it exceeds a certain size in bytes.

2. There is also an open pull-request with a new transport I haven't had a chance to really dig into "fileRotate", which it seems does this kind of date-based rotation: https://github.com/flatiron/winston/pull/120/files

Answer 2

The feature is present and we are using it in production, winston.transports.DailyRotateFile:

var timeFormatFn = function() {     'use strict';     return moment().format(cfg.timeFormat); };  var logger = new(winston.Logger)({     exitOnError: false,     transports: [         new(winston.transports.DailyRotateFile)({             filename: cfg.appLogName,             dirname: __dirname + '/../' + cfg.logsDirectory,             datePattern: cfg.rollingDatePattern,             timestamp: timeFormatFn         }),         new(winston.transports.Console)({             colorize: true,             timestamp: timeFormatFn         })     ] });