Node.js log4js日志管理详解

const log4js = require('log4js')
 
log4js.configure({
 replaceConsole: true,
 appenders: {
  stdout: {//控制台输出
   type: 'stdout'
  },
  req: {//请求日志
   type: 'dateFile',
   filename: 'logs/reqlog/',
   pattern: 'req-yyyy-MM-dd.log',
   alwaysIncludePattern: true
  },
  err: {//错误日志
   type: 'dateFile',
   filename: 'logs/errlog/',
   pattern: 'err-yyyy-MM-dd.log',
   alwaysIncludePattern: true
  },
  oth: {//其他日志
   type: 'dateFile',
   filename: 'logs/othlog/',
   pattern: 'oth-yyyy-MM-dd.log',
   alwaysIncludePattern: true
  }
 },
 categories: {
  default: { appenders: ['stdout', 'req'], level: 'debug' },//appenders:采用的appender,取appenders项,level:设置级别
  err: { appenders: ['stdout', 'err'], level: 'error' },
  oth: { appenders: ['stdout', 'oth'], level: 'info' }
 }
})
 
 
exports.getLogger = function (name) {//name取categories项
 return log4js.getLogger(name || 'default')
}
 
exports.useLogger = function (app, logger) {//用来与express结合
 app.use(log4js.connectLogger(logger || log4js.getLogger('default'), {
  format: '[:remote-addr :method :url :status :response-timems][:referrer HTTP/:http-version :user-agent]'//自定义输出格式
 }))
}

const log4js= require('./log-config')
const logger = log4js.getLogger()//根据需要获取logger
const errlogger = log4js.getLogger('err')
const othlogger = log4js.getLogger('oth')
 
//结合express使用，记录请求日志
app = express()
log4js.useLogger(app,logger)//这样会自动记录每次请求信息，放在其他use上面
//手动记录，可以代替console.log
logger.info('test info 1')
errlogger.err('test error 1')
othlogger.info('test info 2')