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

1var logCfg = {
2    "level":{
3        "production": "warn",
4        "development": "info"
5    },
6    "persist":"error",
7    "max":2
8}

On server side, initialize plugin in server.js

1
2var loglevel = require('loglevel');
3var logger = require('loglevel-prefix-persist/server')
4var log = logger(process.env.NODE_ENV, loglevel, logCfg);
5
6
7var app = express();
8app
9    .use(bodyParser.urlencoded({ extended: false }))
10    .use(bodyParser.json())
11
12//...
13
14if (log.writer) {
15	// if client log persistence is enabled, this will accept and writes logs coming from client side
16    app.use(log.writer);
17}
18
19

On client side, initialize plugin in client.js entry

1var loglevel = require('loglevel');
2var logger = require('loglevel-prefix-persist/client');
3var log = logger('development', loglevel, logCfg);
4

All together (for both client and server)

1
2// namespacing modules
3var log = require('loglevel').getLogger("my/module-name");
4
5// start logging
6log.debug('Debug will not show')
7log.info('Info will show under development, but not in production','config',logCfg)
8log.warn('Warn will always show')
9log.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:

1
2// log level='warn', server persistence only (at 'warn'), log daily forever
3var logCfg = {
4	"level":"warn"
5}
6
7// log level for client+server, no persistence
8var logCfg = {
9	"level": {"server":"info", "client":"warn"}, // regardless of environment
10	"persist":false
11}
12
13// log level for production+development, persist for level='error', max 2 days log
14var logCfg = {
15    "level":{
16        "production": "warn",
17        "development": "info"
18    },
19    "persist":"error",
20    "max":2
21}
22
23// cfg for production+developement, client+server
24var logCfg = {
25    "level":{
26        "production": {"server":"info", "client":"warn"},
27        "development": "debug"
28    },
29    "persist":{
30        "client":"error", // only persist client level='error'
31        "server":true // persist server 'debug' in development, 'info' in production
32    },
33    "max":2
34}
35
36