log4js-node/examples/log-to-files.js

const log4js = require('../lib/log4js');

log4js.configure({
  appenders: {
    file: {
      type: 'file',
      filename: 'important-things.log',
      maxLogSize: 10 * 1024 * 1024, // = 10Mb
      backups: 5, // keep five backup files
      compress: true, // compress the backups
      encoding: 'utf-8',
      mode: 0o0640,
      flags: 'w+',
    },
    dateFile: {
      type: 'dateFile',
      filename: 'more-important-things.log',
      pattern: 'yyyy-MM-dd-hh',
      compress: true,
    },
    out: {
      type: 'stdout',
    },
  },
  categories: {
    default: { appenders: ['file', 'dateFile', 'out'], level: 'trace' },
  },
});

const logger = log4js.getLogger('things');
logger.debug('This little thing went to market');
logger.info('This little thing stayed at home');
logger.error('This little thing had roast beef');
logger.fatal('This little thing had none');
logger.trace('and this little thing went wee, wee, wee, all the way home.');