Node.js - logging / Use morgan and winston

Question

we use morgan in order to log our express transformation:

    var morgan  = require('morgan');
    morgan('combined');
    // a format string
    morgan(':remote-addr :method :url :uuid');
    // a custom function
    morgan(function (req, res) {
      return req.method + ' ' + req.url + ' ' + req.uuid;
    })

Also, we use winston in order to log our other logging:

   var winston = require('winston');
    var logger = new (winston.Logger)({
    transports: [
             new (winston.transports.Console)({ level: 'info' }),
              new (winston.transports.File)({ filename: '/var/log/log-file.log' })
     ]
    });

Is there any way to combine the two loggers together? the situation now is that morgan is write to my standard output, when winston writes to /var/log/log-file.log.

I wish that the logger file will combine from the express transformation information, and from the other information I want (logger.info())..

Answer 1

This article does an excellent job for what you want to do.

http://tostring.it/2014/06/23/advanced-logging-with-nodejs/

For your specific code you probably need something like this:

var logger = new winston.Logger({
    transports: [
        new winston.transports.File({
            level: 'info',
            filename: './logs/all-logs.log',
            handleExceptions: true,
            json: true,
            maxsize: 5242880, //5MB
            maxFiles: 5,
            colorize: false
        }),
        new winston.transports.Console({
            level: 'debug',
            handleExceptions: true,
            json: false,
            colorize: true
        })
    ],
    exitOnError: false
}),

logger.stream = {
    write: function(message, encoding){
        logger.info(message);
    }
};

app.use(require("morgan")("combined", { "stream": logger.stream }));

This will set up Winston to write a log to the console as well as a file. Then you can use the last expression to pass output from the morgan middleware into winston.

Answer 2

Update the last line to remove warning

app.use(require("morgan")("combined", { stream: logger.stream }));

Answer 3

In Typescript:

let logger = new (winston.Logger)({
    exitOnError: false,
    level: 'info',
    transports: [
        new (winston.transports.Console)(),
        new (winston.transports.File)({ filename: 'app.log'})
    ]
})

class MyStream {
    write(text: string) {
        logger.info(text)
    }
}
let myStream = new MyStream()
app.use(morgan('tiny', { stream: myStream }));