loglevel-prefix-persist

loglevel plugin - Support for the following:

• (Almost) Isomorphic - passes single log config that can be used on both client and server
• can be used by client or server alone
• client & server log message prefix with [your/module-name]
• client & server log persistence
• additional datetime information, text color to server log

Uses

• file-stream-rotator to rotate logs daily
• node-schedule to clean up files over configured maximum number of log files

#Usage Assuming the following simple config

var logCfg = {
    "level":{
        "production": "warn",
        "development": "info"
    },
    "persist":"error",
    "max":2
}

On server side, initialize plugin in server.js

var loglevel = require('loglevel');
var logger = require('loglevel-prefix-persist/server')
var log = logger(process.env.NODE_ENV, loglevel, logCfg);


var app = express();
app
    .use(bodyParser.urlencoded({ extended: false }))
    .use(bodyParser.json())

//...

if (log.writer) {
	// if client log persistence is enabled, this will accept and writes logs coming from client side
    app.use(log.writer);
}

On client side, initialize plugin in client.js entry

var loglevel = require('loglevel');
var logger = require('loglevel-prefix-persist/client');
var log = logger('development', loglevel, logCfg);

All together (for both client and server)

// namespacing modules
var log = require('loglevel').getLogger("my/module-name");

// start logging
log.debug('Debug will not show')
log.info('Info will show under development, but not in production','config',logCfg)
log.warn('Warn will always show')
log.error('Error will always show')

#Result server

client

#Config

• Default environment is 'development'
• Default log level is 'info'
• Default persistence for server is same as log level
• Default persistence for client is disabled
• If persistence is turned on and max is not set, old files will not be cleaned up

Config examples:

// log level='warn', server persistence only (at 'warn'), log daily forever
var logCfg = {
	"level":"warn"
}

// log level for client+server, no persistence
var logCfg = {
	"level": {"server":"info", "client":"warn"}, // regardless of environment
	"persist":false
}

// log level for production+development, persist for level='error', max 2 days log
var logCfg = {
    "level":{
        "production": "warn",
        "development": "info"
    },
    "persist":"error",
    "max":2
}

// cfg for production+developement, client+server
var logCfg = {
    "level":{
        "production": {"server":"info", "client":"warn"},
        "development": "debug"
    },
    "persist":{
        "client":"error", // only persist client level='error'
        "server":true // persist server 'debug' in development, 'info' in production
    },
    "max":2
}