egg-logger's Introduction

egg-logger

Egg logger.

Including two base class, Logger and Transport:

Transport: Save log to file, stdout/stderr and network.
Logger: A logger can contain multi transports.

Install

$ npm i egg-logger

Usage

Create a Logger and add a file Transport.

const Logger = require('egg-logger').Logger;
const FileTransport = require('egg-logger').FileTransport;
const ConsoleTransport = require('egg-logger').ConsoleTransport;

const logger = new Logger();
logger.set('file', new FileTransport({
  file: '/path/to/file',
  level: 'INFO',
}));
logger.set('console', new ConsoleTransport({
  level: 'DEBUG',
}));
logger.debug('debug foo'); // only output to stdout
logger.info('info foo');
logger.warn('warn foo');
logger.error(new Error('error foo'));

Enable / Disable Transport

logger.disable('file');
logger.info('info'); // output nothing
logger.enable('file');
logger.info('info'); // output 'info' string

Redirect

Redirect error log to other logger.

logger.redirect('error', errorLogger);
logger.error(new Error('print to errorLogger')); // equal to `errorLogger.error`

Reload

logger.reload(); // will close the existing write stream and create a new one.

Custom Transport

You can make your own Transport for logging，e.g.: send log to your logging server.

const urllib = require('urllib');
const Transport = require('egg-logger').Transport;

class UrllibTransport extends Transport {

  log(level, args, meta) {
    const msg = super.log(level, args, meta);
    return urllib.request('url?msg=' + msg);
  }
}

const logger = new Logger();
logger.set('remote', new UrllibTransport({
  level: 'DEBUG',
}));
logger.info('info');