logify

"Batteries included, but removable" logging solution for node/io.js

Project is under HEAVY development, expect things to break, etc

Install

Install the package with npm:

$ npm install logify

Usage

import Logger from 'logify';

const logger = new Logger();

// ...

logger.debug('Hello world!');
logger.info('I can has %s interpolation', 'string');
logger.notice(context, 'I can attach objects to the log %s', 'message');
logger.warn(err);
logger.error(err, 'Custom error messages too \o/');

API

logger.transform(fn)

Transform the log entry with fn(entry) before processing.

logger.transform(field, fn[, always])

Transform field field with fn(entry[field]) before processing. If always is true, the field is processed even if it is undefined.

logger.child(context)

Create child logger with extended context.

logger.component(name)

Create child logger for component

const logger = new Logger();

const authLogger = logger.component('auth');
// { component: 'auth' }

const facebookAuthLogger = authLogger.component('facebook');
// { component: 'auth.facebook' }

logger.add(transport)

Forward log entries to transport.

Transports

stream(s, [formatter])

Write log events to s with the given formatter. The default formatter is jsonLine.

udp(socket, port, address, [formatter])

Write log event to socket, send to address:port with the given formatter. The default formatter is jsonLine

console([formatter])

Write log events to process.stdout or process.stderr with the given formatter (defaults to console formatter). Output stream is based on the severity.

Filters

filter(fn, ...appenders)

Forward log messages to appenders, based on the truthiness of fn(message).

when(field, parrent, ...appenders)

Forward log messages to appenders, based on pattern matching on the field field.

Formatters

json

Stringified JSON output.

jsonLine

Newline-delimited stringified JSON output.

console

Pretty, human-readable format, with colors if possible.