Node JS - Log4js

log4js Node JS, log4js Comments

1. install package

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npm i config
npm i log4js

2. Creat config/default.json

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{
  "logger": {
    "appenders": {
      "file": {
        "type": "file",
        "filename": "logs/log.log",
        "maxLogSize": 104857600,
        "backups": 10,
        "layout": {
          "type": "json"
        }
      },
      "console": {
        "type": "console"
      }
    },
    "categories": {
      "default": {
        "appenders": ["file"],
        "level": "trace"
      }
    }
  }
}

3. Creat log.js

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const config = require('config');
const log4js = require('log4js');

log4js.addLayout('json', function(config) {
  return function(logEvent) {
    return JSON.stringify(logEvent);
  };
});

log4js.configure(config.logger);

module.exports = {
  log4js,
  getLogger: log4js.getLogger
};

4. Ceate index.js

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const logger = require('./log').getLogger('logtest');
logger.trace('testTrace');
logger.debug('testDebug');
logger.info('testInfo');
logger.warn('testWarn');
logger.error('testError');
logger.fatal('testFatal');

5. Run

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node index.js

index

Demo

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