log4js-node：node.js日志框架输出到文件

文档

• github: https://github.com/log4js-node/log4js-node
• doc https://log4js-node.github.io/log4js-node/
• npmjs https://www.npmjs.com/package/log4js

安装

node -v
v16.14.0

pnpm install log4js

package.json

{
    
    
  "type": "module",
  "dependencies": {
    
    
    "log4js": "^6.6.1"
  }
}

示例

import log4js from "log4js";

const logger = log4js.getLogger();
logger.level = "debug";
logger.debug("Some debug messages");

运行输出

$ node app.js
[2022-08-14T17:28:38.108] [DEBUG] default - Some debug messages

自定义配置，输出到文件

// log4js.config.js
export default {
    
    
  appenders: {
    
    
    output: {
    
    
      type: "file",
      filename: "logger.log",
      maxLogSize: "1K", //  K, M, G
      backups: 3,
      compress: false,

      layout: {
    
    
        type: "pattern",
        pattern: "[%d{yyyy-MM-dd hh:mm:ss}] [%p] %f{1} line-%l: %m",
      },
    },
  },
  categories: {
    
    
    default: {
    
    
      appenders: ["output"],
      level: "debug",
      enableCallStack: true
    },
  },
};

// app.js
import log4js from "log4js";
import log4jsConfig from "./log4js.config.js";

// 配置
log4js.configure(log4jsConfig);

const logger = log4js.getLogger();

logger.debug("Some debug messages");

输出格式如下

[2022-08-14 18:14:08] [DEBUG] app.js line-18: Some debug messages