can I change the color of log data in winston?

Question

I happened to use bunyan to log the the data . I wanted the logs be printed with appropriate colors like errors in red , debug yellow .. etc; unfortunately I couldn't find anyways to do that . And now I would like to know if its possible with winston. Can I change the color of log data in winston ?

here is the code that I executed .

  var logger = require("winston-color");
  var winston = require('winston');  
  var util    = require('util');

  var logFilename = __dirname + '/logfile.log';

  var logger = new (winston.Logger)({
    transports: [
      new (winston.transports.Console)(),
      new (winston.transports.File)({ 
      filename: 'logfile.log',
      timestamp:true 
     }),
      new (winston.transports.File)({
      name: 'error-log',
      filename: 'error.log',
      level: 'error'
      }),

     new (winston.transports.File)({
     name: 'info-log',
     filename: 'info.log',
     level: 'info'
     }),
    ]
  });
  logger.info('Hello Winston info!');
  logger.debug('Hello Winston debug!');
  logger.warn('Hello Winston warn!');
  logger.info('Hello again distributed logs'); 
  logger.error('error1');
  logger.error('error2');

the output screen shot here

working code's output here here

Answer 1

If you look for a custom color schema you can write your own transporter like this

import winston from "winston";
import Transport from "winston-transport";

const Colors = {
    info: "\x1b[36m",
    error: "\x1b[31m",
    warn: "\x1b[33m",
    verbose: "\x1b[43m",
};

class SimpleConsoleTransport extends Transport {
    constructor() {
        super();
    }
    log = (info, callback) => {
        const { level, message, stack } = info;
        console.log(
                `${Colors[level]}${level}\t${message}\x1b[0m`,
                stack ? "\n" + stack : ""
            )
        if (callback) {
            callback();
        }
    };
}

then config your winston instance this way:

winston.configure({
    transports: [new SimpleConsoleTransport()],
});

these are the whole list of colors you can use:

Reset = "\x1b[0m"
Bright = "\x1b[1m"
Dim = "\x1b[2m"
Underscore = "\x1b[4m"
Blink = "\x1b[5m"
Reverse = "\x1b[7m"
Hidden = "\x1b[8m"

FgBlack = "\x1b[30m"
FgRed = "\x1b[31m"
FgGreen = "\x1b[32m"
FgYellow = "\x1b[33m"
FgBlue = "\x1b[34m"
FgMagenta = "\x1b[35m"
FgCyan = "\x1b[36m"
FgWhite = "\x1b[37m"

BgBlack = "\x1b[40m"
BgRed = "\x1b[41m"
BgGreen = "\x1b[42m"
BgYellow = "\x1b[43m"
BgBlue = "\x1b[44m"
BgMagenta = "\x1b[45m"
BgCyan = "\x1b[46m"
BgWhite = "\x1b[47m"

Answer 2

Yes you can. You can use the following code that I am using in my project.

logger/WinstonPlugin.js

/* jslint node: true */
/* jshint esversion: 6 */

'use strict';
const Winston = require('winston');
const logLevel = 'debug';

var logger;

(function createLogger() {

    logger = new(Winston.Logger)({
        transports: [
            new(Winston.transports.Console)({
                level: logLevel,
                colorize: true,
                timestamp: function () {
                    return (new Date()).toLocaleTimeString();
                },
                prettyPrint: true
            })
        ]
    });

    Winston.addColors({
        error: 'red',
        warn: 'yellow',
        info: 'cyan',
        debug: 'green'
    });
})();

module.exports = logger;

And anytime you needed the Winston in any your code file. You can access like below:

const Winston = require('logger/WinstonPlugin');
Winston.info('This is a info statement');
Winston.debug('This is a debug statement');
Winston.warn('This is a warning statement');
Winston.error('This is a error statement');

and you will see the colored output in the console.