restify-winston.js

#!/usr/bin/env node
// A simple base restify server. A baseline for comparison with
// the other servers here.

var restify = require('restify');
var winston = require('winston');
var bunyan = require('bunyan');


// Whatever Winston logger setup your application wants.
var log = new winston.Logger({
    transports: [
        new winston.transports.Console({colorize: true, json: false})
    ]
});


/**
 * A Bunyan raw stream object (i.e. has a `.write(rec)` method that takes a
 * Bunyan log record) that shims logging to a given Winston logger.
 *
 * @param {winston.Logger} wlog is a Winston Logger to which to shim.
 */
function Bunyan2Winston(wlog) {
    this.wlog = wlog
}
Bunyan2Winston.prototype.write = function write(rec) {
    // Map to the appropriate Winston log level (by default 'info', 'warn'
    // or 'error') and call signature: `wlog.log(level, msg, metadata)`.
    var wlevel;
    if (rec.level <= bunyan.INFO) {
        wlevel = 'info';
    } else if (rec.level <= bunyan.WARN) {
        wlevel = 'warn';
    } else {
        wlevel = 'error';
    }

    // Note: We are *modifying* the log record here. This could be a problem
    // if our Bunyan logger had other streams. This one doesn't.
    var msg = rec.msg;
    delete rec.msg;

    // Remove internal bunyan fields that won't mean anything outside of
    // a bunyan context.
    delete rec.v;
    delete rec.level;
    // TODO: more?

    // Note: Winston doesn't handle *objects* in the 'metadata' field well
    // (e.g. the Bunyan record 'time' field is a Date instance, 'req' and
    // 'res' are typically objects). With 'json: true' on a Winston transport
    // it is a bit better, but still messes up 'date'. What exactly to do
    // here is perhaps user-preference.
    rec.time = String(rec.time);
    //Object.keys(rec).forEach(function (key) {
    //    if (typeof(rec[key]) === "object") {
    //        rec[key] = JSON.stringify(rec[key])
    //    }
    //});

    this.wlog.log(wlevel, msg, rec);
}


// Pass a Bunyan logger to restify that shims to our winston Logger.
var shim = bunyan.createLogger({
    name: 'myapp',
    streams: [{
        type: 'raw',
        level: 'trace',
        stream: new Bunyan2Winston(log)
    }]
});

var server = restify.createServer({
    name: 'myapp',
    version: '1.0.0',
    log: shim
});

server.get('/ping', function (req, res, next) {
    res.send('pong');
    return next();
});

server.listen(8080, function () {
    log.info(server.name + ' listening at ' + server.url);
});