Logging Example: log4js

log4js_min.js

var log4js = require('log4js'); 

log4js.configure({
 appenders: [
   {
      "category": "tests",
      "type": "logLevelFilter",
      "level": "INFO",
      "maxLevel": "INFO",
      "appender": {
        "type": "console",
        
        // "layout": {
        //   "type": "messagePassThrough"
        //   }
        }
    },

   { type: 'file', 
      filename: 'tests_all.log', 
      category: 'tests' 
   },

   {
      "category": "tests",
      "type": "logLevelFilter",
      "level": "DEBUG",
      "maxLevel": "DEBUG",
      "appender": {
        "type": "file",
        "filename": "tests_debugs.log",
        "layout": {
          "type": "messagePassThrough"
          }
        }
    },
  ],
  "levels": {
        //"[all]": "INFO",
        "tests": "ALL",
    }
});


var logger = log4js.getLogger('tests');
//logger.setLevel('ERROR');

logger.trace('Entering cheese testing');
logger.debug({'Got cheese':1});
logger.info('Cheese is Gouda.');
logger.warn('Cheese is quite smelly.');
logger.error('Cheese is too ripe!');
logger.fatal('Cheese was breeding ground for listeria.');

logging_rotation.js

var log4js = require('log4js');

log4js.configure({
  appenders: [
    { 
        type: 'console' 
    },
    
    { 
        type: 'dateFile', 
        filename: 'logging.log',
        pattern: "-yyyy-MM-dd",
        backups: 2,
        category: "info"
    }
  ],
  "levels": {
        "[all]": "INFO",
  },
  replaceConsole: true
});

var logger = log4js.getLogger("info");
var debug_logger = log4js.getLogger("error");

console.log('test');
console.dir({'test':1});