golog

GoLog

A light-weight heavily inspired logging library for NodeJS. Checkout the main features:

• JSON output as well as simple date-level-msg format.
• Auto-format error and request objects.
• printf-like formatting on messages.
• Automatic pid field on log entries.
• Broadcast to many files/streams.
• Individual logging level for each file/stream.

Get Started

1. Install with: npm i -P golog.
2. Setup a logger:

const GoLog = require('require');

// Crate a new logger.
var log = new GoLog();

// Add a Writable Stream to receive log entries.
log.addStream( 'my-stdout', process.stdout );

// Add a file where to write log entries.
log.addFile( 'my-file', '/path/to/file' );

1. Create new log entries with one of the supported levels:

log.debug('Main log message');
log.info('Main log message');
log.warn('Counting, %d, %d, %d... %s', 1, 2, 3, 'Foo!');
log.error('Main log message');
log.fatal({ merge: 'this', object: 'with', the: 'entry' }, 'The MSG');

Other Features

If you want to setup a logger with a single stream or file go with the one-liner.

var slog = new GoLog({ stream: process.stdout });
var flog = new GoLog({ file: '/path/to/file' });

If you have many loggers writing to the same stream, name each logger for better visibility.

var l1 = new GoLog({ name: 'log-a', stream: process.stdout });
l1.warn('Hey!');
var l2 = new GoLog({ name: 'log-b', stream: process.stdout });
l2.warn('Ho!');

Default loggers only log entries of level warn or higher. Change the level for an entire logger.

var log = new GoLog({ level: 'debug', stream: process.stdout });
log.debug('Let\'s go!');

If you need these files right now, just change to a mode with better aesthetics.

var log = new GoLog({ stream: process.stdout });
log.warn('This is an ugly JSON');

log.mode = 'pretty'
log.warn('This is a cute JSON');

log.mode = 'minimal'
log.warn('This is just readable');

If you need to stop logging to a given stream/file just use removeStream.

var log = new GoLog({ stream: process.stdout });
log.addFile('some-file', '/path/to/file');
log.warn('This goes to stdout and file');

log.removeStream('main');
log.warn('This goes to file only');

log.removeStream('some-file');
log.warn('This goes nowhere');

If you happen to need to setup some listeners.

var log = new GoLog();

log.on('fatal', ent => console.log('Show me once'));
log.on('entry', ent => console.log('Show me twice'));

log.fatal('The fatal entry');
log.debug('The debug entry');

If you want to log some information about an Error instance, just add it as a key to the data object.

log.warn({ err: new Error('My error') }, 'The message lives on');

GoLog also formats http request objects.

const http = require('http');
const GoLog = require('require');

var log = new GoLog({ stream: process.stdout });

var server = http.createServer(function(req, res){
    res.end();
    log.warn({ req: req }, 'The message lives on');
}).listen(8765);

http.get('http://localhost:8765');

Reporting Bugs

If you have found any problems with this module, please:

1. Open an issue.
2. Describe what happened and how.
3. Also in the issue text, reference the label ~bug.

We will make sure to take a look when time allows us.

Proposing Features

If you wish to get that awesome feature or have some advice for us, please:

1. Open an issue.
2. Describe your ideas.
3. Also in the issue text, reference the label ~proposal.

Contributing

If you have spotted any enhancements to be made and is willing to get your hands dirty about it, fork us and submit your merge request so we can collaborate effectively.