Node.js - How to add timestamp to logs using Winston library?

Question

I want to add timestamp to logs.

What is the best way to achieve this?

Thanks.

This remains too broad because you canNOT do it from the client machine. — Joshua, Apr 20 '16 at 02:01

score 141 · Answer 1 · answered Feb 01 '18 at 22:55

Above answers did not work for me. In case you are trying to add timestamp to your logs using the latest version of Winston - 3.0.0-rc1, this worked like charm:

    const {transports, createLogger, format} = require('winston');

    const logger = createLogger({
        format: format.combine(
            format.timestamp(),
            format.json()
        ),
        transports: [
            new transports.Console(),
            new transports.File({filename: 'logs/error/error.log', level: 'error'}),
            new transports.File({filename: 'logs/activity/activity.log', level:'info'})
        ]
    });

I used 'format.combine()'. Since I needed timestamp on all my transports, I added the formatting option within the createLogger, rather than inside each transport. My output on console and on file (activity.log) are as follows:

{"message":"Connected to mongodb","level":"info","timestamp":"2018-02-01T22:35:27.758Z"}
{"message":"Connected to mongodb","level":"info","timestamp":"2018-02-01T22:35:27.758Z"}

We can add formatting to this timestamp in 'format.combine()' as usual using:

format.timestamp({format:'MM-YY-DD'})

Note that `format.timestamp` **has** to come before `format.json` (if you're using that latter) — Kagiso Marvin Molekwa, Sep 10 '21 at 08:39
@marvinIsSacul not true, I have them swapped and it works anyway! — OtaconKiko, Oct 13 '21 at 15:33
mhhh alright @OtaconKiko not sure why it didn't on my side :think — Kagiso Marvin Molekwa, Oct 13 '21 at 16:00

score 120 · Accepted Answer · edited May 18 '15 at 08:48

120

I was dealing with the same issue myself. There are two ways I was able to do this.

When you include Winston, it usually defaults to adding a Console transport. In order to get timestamps to work in this default case, I needed to either:

Remove the console transport and add again with the timestamp option.
Create your own Logger object with the timestamp option set to true.

The first:

var winston = require('winston');
winston.remove(winston.transports.Console);
winston.add(winston.transports.Console, {'timestamp':true});

The second, and cleaner option:

var winston = require('winston');
var logger = new (winston.Logger)({
    transports: [
      new (winston.transports.Console)({'timestamp':true})
    ]
});

Some of the other options for Console transport can be found here:

level: Level of messages that this transport should log (default 'debug').
silent: Boolean flag indicating whether to suppress output (default false).
colorize: Boolean flag indicating if we should colorize output (default false).
timestamp: Boolean flag indicating if we should prepend output with timestamps (default false). If function is specified, its return value will be used instead of timestamps.

edited May 18 '15 at 08:48

Wilfred Springer

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answered Apr 26 '12 at 20:38

imagreenplant

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1

Amazing and simple at the same time. Thank you! – kolrie Apr 27 '12 at 00:50
7

This is great. I usually wrap this in a dedicated file so that I can easily get my configured logger from any file, i.e., I put the above code (option 2) in a new file logger.js, followed by module.exports = logger; then from any file I do var logger = require('./logger.js') and can then do logger.info('hello') from any file and get the same configuration of Winston. – JHH May 28 '15 at 08:58
TypeError: (intermediate value) is not a function – Urasquirrel Jul 24 '19 at 19:37
3

This does not appear to work in the current version of Winston. Try one of the other answers instead. – AverageHelper Apr 14 '21 at 04:15

score 36 · Answer 3 · edited Sep 02 '20 at 18:46

36

We can do like this also

var winston = require('winston');
const { createLogger, format, transports } = require('winston');
var config = require('../configurations/envconfig.js');

var loggerLevel = process.env.LOGGERLEVEL ||  config.get('LOGGERLEVEL');

var logger = winston.createLogger({
  format: format.combine(
    format.timestamp({
      format: 'YYYY-MM-DD HH:mm:ss'
    }),
    format.printf(info => `${info.timestamp} ${info.level}: ${info.message}`+(info.splat!==undefined?`${info.splat}`:" "))
  ),
  transports: [
    new (winston.transports.Console)({ level: loggerLevel }),
  ]
});
module.exports = logger;

edited Sep 02 '20 at 18:46

Ynjxsjmh

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answered Apr 30 '18 at 11:02

Biswadev

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Does this also work for `logger.info('Message', someObject)`? I setup a custom format using combine and I can't seem to get the `someObject` included in the log message. – SomethingOn Jun 25 '18 at 19:20
2

I was able to get `someObject` included by using the following printf statement `${info.timestamp} [${info.level.toUpperCase()}]: ${info.message} ${JSON.stringify(info)}`. It includes the level, timestamp and message which I guess I could delete. – SomethingOn Jun 25 '18 at 19:28

score 10 · Answer 4 · answered Mar 15 '14 at 19:23

10

You can use built-in util and forever to achieve logging with timestap for your nodejs server. When you start a server add log output as part of the parameter:

forever start -ao log/out.log server.js

And then you can write util in your server.js

server.js

var util = require('util');
util.log("something with timestamp");

The output will look something like this to out.log file:

out.log

15 Mar 15:09:28 - something with timestamp

answered Mar 15 '14 at 19:23

KTU

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Unfortunately, `util.error()` skips timestamping the output. – Saran Feb 21 '15 at 22:55

score 7 · Answer 5 · answered Aug 05 '20 at 22:10

I took Biswadev's answer and created a stringified JSON object. This way if i need to process the logs later it will be in a well structured format.

const winston = require('winston');
const { createLogger, format, transports } = require('winston');

const dotenv = require('dotenv');
dotenv.config();

var logger = createLogger({
    level: 'info',
    format: format.combine(
        format.timestamp({
            format: 'YYYY-MM-DD HH:mm:ss',
        }),
        format.printf((info) =>
            JSON.stringify({
                t: info.timestamp,
                l: info.level,
                m: info.message,
                s: info.splat !== undefined ? `${info.splat}` : '',
            }) + ','
        )
    ),
});

if (process.env.NODE_ENV !== 'PRODUCTION') {
    logger.add(new transports.Console({ format: winston.format.cli() }));

    // Turn these on to create logs as if it were production
    // logger.add(new transports.File({ filename: 'log/output/error.log', level: 'error' }));
    // logger.add(new transports.File({ filename: 'log/output/warn.log', level: 'warn' }));
    // logger.add(new transports.File({ filename: 'log/output/info.log', level: 'info' }));
} else {
    logger.add(new transports.File({ filename: 'log/output/error.log', level: 'error' }));
    logger.add(new transports.File({ filename: 'log/output/warn.log', level: 'warn' }));
    logger.add(new transports.File({ filename: 'log/output/info.log', level: 'info' }));
}

module.exports = {
    logger,
};

Usage:

app.listen(port, () => logger.info(`app is running on port ${port}`));

Output:

info.log file:

{"t":"2020-08-06 08:02:05","l":"info","m":"app is running on port 3001","s":""},

Console:

info:    app is running on port 3001

love that... copy paste solution !! – Mr.P Dec 15 '20 at 13:56 — Mr.P, Dec 15 '20 at 13:56

Tamil · Answer 6 · 2012-07-20T06:55:25.943

5

Although I'm not aware of winston, this is a suggestion. I use log4js for logging & my logs by default look like this

[2012-04-23 16:36:02.965] [INFO] Development - Node Application is running on port 8090
[2012-04-23 16:36:02.966] [FATAL] Development - Connection Terminated to  '127.0.0.1' '6379'

Development is the environment of my node process & [INFO|FATAL] is log level

Maintaining different profiles for logging is possible in log4js. I have Development & Production profiles. Also there are logger types like rolling file appender, console appender, etc. As a addon your log files will be colorful based on the log level [Trace, Info, Debug, Error, Fatal] ;)

~~log4js will override your console.log~~ It is a configurable parameter now in 0.5+

edited Jul 20 '12 at 06:55

answered Apr 23 '12 at 11:18

Tamil

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FYI: Newer versions of log4js-node (0.5+) don't automatically override console.log. – Jeff Hiltz Jul 19 '12 at 20:18
@jeffhiltz Ya you are right :) Now it is a configurable parameter – Tamil Jul 20 '12 at 06:54

score 4 · Answer 7 · edited Oct 15 '17 at 15:20

4

we could use console-stamp to add timestamp and log level to the existing console: require('console-stamp')(console, '[yyyy-mm-dd HH:MM:ss.l]')

See https://github.com/starak/node-console-stamp for the details

edited Oct 15 '17 at 15:20

Arkadiusz Cieśliński

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answered Jun 21 '16 at 19:45

khoi nguyen

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Except it does not add timestamp to File transports. – kisp Apr 23 '21 at 14:56

score 2 · Answer 8 · answered Jun 30 '16 at 14:01

Sometimes default timestamp format can be not convenient for you. You can override it with your implementation.

Instead of

var winston = require('winston');
var logger = new (winston.Logger)({
transports: [
  new (winston.transports.Console)({'timestamp':true})
]
});

you can write

var winston = require('winston');
var logger = new (winston.Logger)({
transports: [
  new (winston.transports.Console)({
     'timestamp': function() {
        return <write your custom formatted date here>;
     }
  })
]
});

See https://github.com/winstonjs/winston#custom-log-format for the details

score 2 · Answer 9 · answered Aug 21 '19 at 16:01

Another solution is wrapping the logger into a file that exports some functions like logger.info(), logger.error(), etc. then you just pass an extra key to be sent on every message log.

loggerService.js

const logger = winston.createLogger({ ... })

function handleLog(message, level) {
  const logData = {
    timestamp: Date.now(),
    message,
  }

  return logger[level](logData)
}

function info(message) {
  handleLog(message, 'info')
}

function error(message) {
  handleLog(message, 'error')
}

function warn(message) {
  handleLog(message, 'warn')
}

module.exports = {
  info,
  error,
  warn
}

whatever-file.js

const logger = require('./services/loggerService')

logger.info('Hello World!')

your-log.log

{"timestamp":"2019-08-21 06:42:27","message":"Hello World!","level":"info"}

Node.js - How to add timestamp to logs using Winston library?

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