NodeJS - Winston

• Winston是Node.js最流行的日志框架之一，设计为一个简单通用的日志库，支持多传输（在Winston中，一个传输实质上代表储存设备，也就是数据最终保存在哪里），每个Winston实例都可以对不同级别的日志配置不同的传输。
• config.js中的配置

const winston = require('winston');

let initLoggerConfig = function (config) {
    /**
     * Create logger
     */
    let logger = new (winston.Logger)(config.logger),
        jobLogger = new(winston.Logger)(config.jobLogger);

    config.log = function () {
        logger.log(arguments);
    };

    config.info = function () {
        logger.info(arguments);
    };

    config.error = function () {
        logger.error(arguments);
    };

    config.debug = function () {
        logger.debug(arguments);
    };

    config.jobInfo = function () {
        jobLogger.info(arguments);
    };
    
    config.jobError = function () {
        jobLogger.error(arguments);
    };
};

• production.js中的配置

const path = require('path'),
    winston = require('winston'),
    DailyRotateFile = require('winston-daily-rotate-file');
module.exports = {
    env: 'production',
    logger: {
        transports: [
            new winston.transports.Console({
                colorize: true
            }),
            new DailyRotateFile({
                level: 'silly',
                filename: path.resolve('./logs/access-'),
                datePattern: 'yyyy-MM-dd.log',
                maxsize: 5242880 /* 5MB */
            })
        ]
    },
    jobLogger: {
        transports: [
            new winston.transports.Console({
                colorize: true
            }),
            new DailyRotateFile({
                level: 'silly',
                filename: path.resolve('./logs/jobs-'),
                datePattern: 'yyyy-MM-dd.log',
                maxsize: 5242880 /* 5MB */
            })
        ]
    },
    showErrorStack: process.env.SHOW_ERROR_STACK === 'true',
    livereload: false
};

• 即config.js中的配置实际上是这样的

	let logger = new (winston.Logger)(config.logger)
	为
	let logger = new (winston.Logger)(
	{
        transports: [
            new winston.transports.Console({
                colorize: true
            }),
            new DailyRotateFile({
                level: 'silly', // 要记录的消息级别。0：error 1：warn 2：info 3：verbose 4：debug 5：silly 
                filename: path.resolve('./logs/access-'), // 用于将日志数据写入的文件。
                datePattern: 'yyyy-MM-dd.log',
                maxsize: 5242880 /* 5MB */
            })
        ]
    }
  )

• 生成日志文件示例
  access-2018-11-11.log
  jobs-2018-11-11.log
• 使用

config.info('创建审方订单成功2。');
config.error('创建审方订单成功3。');
config.debug('创建审方订单成功4。');

• 输出

{"level":"info","message":"{ '0': '创建审方订单成功2。' }","timestamp":"2018-11-28T09:57:18.841Z"}
{"level":"error","message":"{ '0': '创建审方订单成功3。' }","timestamp":"2018-11-28T09:57:18.843Z"}
{"level":"debug","message":"{ '0': '创建审方订单成功4。' }","timestamp":"2018-11-28T09:57:18.843Z"}