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Egg logger.


Including two base class, Logger and Transport:

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


$ npm i egg-logger


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'info foo');
logger.warn('warn foo');
logger.error(new Error('error foo'));

Enable / Disable Transport

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


Duplicate error log to other logger.

Accept an options.excludes to special whether excludes some tranports.

logger.duplicate('error', errorLogger, { excludes: [ 'console' ]});
logger.error(new Error('print to errorLogger')); // will additional call `errorLogger.error`


Redirect special level log to other logger.

oneLogger.redirect('debug', debugLogger); // all debug level logs of `oneLogger` will delegate to debugLogger


logger.reload(); // will close the exists 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',



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