WinstonJS日志拦截与参数注入：实现全局关联ID等自定义信息

import winston from 'winston';
// 假设 correlator 是一个用于获取当前上下文关联ID的库
// 在实际应用中，这可能是一个基于async_hooks或类似机制实现的上下文管理工具
import { getId as getCorrelationId } from './correlator'; // 示例导入

/**
 * 创建一个Winston格式器，用于注入关联ID。
 * @returns {winston.FormatWrap} 返回一个Winston格式器实例。
 */
export const correlationInjection = winston.format((info) => {
  // 从上下文中获取关联ID，如果不存在则不添加
  const correlationId = getCorrelationId();
  if (correlationId) {
    info.correlationId = correlationId;
  }
  return info;
});

import winston from 'winston';
import { correlationInjection } from './formats/correlationInjection'; // 导入我们创建的格式器

// 配置Winston日志器
const logger = winston.createLogger({
  level: 'info', // 设置默认日志级别
  // 使用 combine 组合多个格式器
  format: winston.format.combine(
    correlationInjection(), // 首先执行关联ID注入
    winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }), // 添加时间戳
    winston.format.errors({ stack: true }), // 捕获错误堆栈
    winston.format.json() // 将所有日志信息输出为JSON格式
  ),
  transports: [
    new winston.transports.Console(), // 输出到控制台
    new winston.transports.File({ filename: 'combined.log' }), // 输出到文件
  ],
});

export default logger;

import logger from './logger'; // 导入配置好的logger
import { runInContext } from './correlator'; // 假设的上下文管理工具

// 模拟一个请求处理函数
function handleRequest(requestId) {
  // 在一个特定的上下文中运行代码，以确保getCorrelationId()能获取到正确的requestId
  runInContext(requestId, () => {
    logger.info(`Processing request: ${requestId}`);
    try {
      // 模拟一些业务逻辑
      if (Math.random() > 0.5) {
        throw new Error('模拟业务逻辑错误');
      }
      logger.debug('Some detailed debug info.');
      logger.warn('A potential issue detected.');
    } catch (error) {
      logger.error('An error occurred during request processing.', error);
    }
    logger.info(`Request ${requestId} finished.`);
  });
}

// 模拟不同的请求
handleRequest('req-123');
handleRequest('req-456');

{"level":"info","message":"Processing request: req-123","correlationId":"req-123","timestamp":"2023-10-27 10:30:00"}
{"level":"debug","message":"Some detailed debug info.","correlationId":"req-123","timestamp":"2023-10-27 10:30:00"}
{"level":"error","message":"An error occurred during request processing.","correlationId":"req-123","timestamp":"2023-10-27 10:30:00","stack":"Error: 模拟业务逻辑错误\n    at handleRequest..."}
{"level":"info","message":"Request req-123 finished.","correlationId":"req-123","timestamp":"2023-10-27 10:30:00"}
{"level":"info","message":"Processing request: req-456","correlationId":"req-456","timestamp":"2023-10-27 10:30:01"}
...