从零搭建 Node.js 企业级 Web 服务器（十一）：定时任务

配置定时任务

定时任务也就是由时间触发的执行过程，属于很常见的业务逻辑。Unix 在早期版本就提供了定时任务调度模块 Cron，并在各类 Linux 系统上沿用至今。Cron 的配置文件 crontab 具有全面却清晰的格式，能够解决大多数场景下的定时任务配置问题，企业级服务器可以使用类 crontab 的格式灵活配置的各种定时任务逻辑，以下为 crontab 的格式：

# Example of job definition:
# .---------------- minute (0 - 59)
# |  .------------- hour (0 - 23)
# |  |  .---------- day of month (1 - 31)
# |  |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |  |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7) OR sun,mon,tue,wed,thu,fri,sat
# |  |  |  |  |
# *  *  *  *  * user-name  command to be executed

本章将基于上一章已完成的工程 licg9999/nodejs-server-examples - 10-log 通过 node-schedule 以类似 crontab 的方式配置定时任务，检测可能含有网络攻击的店铺信息并通过 nodemailer 将可疑店铺信息邮件发送给管理员。在工程根目录执行 node-schedule 与 nodemailer 的安装命令：

$ yarn add node-schedule nodemailer # 本地安装 node-schedule、nodemailer
# ...
info Direct dependencies
├─ node-schedule@1.3.2
└─ nodemailer@6.4.11
# ...

网络攻击巡检

现在实现对网络攻击信息的定时检测与报警的逻辑。先补充服务层逻辑：

// src/services/shop.js
const { Shop } = require('../models');

class ShopService {
  async init() {}

-  async find({ id, pageIndex = 0, pageSize = 10, logging }) {
+  async find({ id, pageIndex = 0, pageSize = 10, where, logging }) {
    if (id) {
      return [await Shop.findByPk(id, { logging })];
    }

    return await Shop.findAll({
      offset: pageIndex * pageSize,
      limit: pageSize,
+      where,
      logging,
    });
  }
  // ...
}
// ...

// src/services/mail.js
const { promisify } = require('util');
const nodemailer = require('nodemailer');
const { mailerOptions } = require('../config');

class MailService {
  mailer;

  async init() {
    this.mailer = nodemailer.createTransport(mailerOptions);
    await promisify(this.mailer.verify)();
  }

  async sendMail(params) {
    return await this.mailer.sendMail({
      from: mailerOptions.auth.user,
      ...params,
    });
  }
}

let service;
module.exports = async () => {
  if (!service) {
    service = new MailService();
    await service.init();
  }
  return service;
};

// src/config/index.js
const merge = require('lodash.merge');
const logger = require('../utils/logger');
const { logging } = logger;

const config = {
  // 默认配置
  default: {
    // ...
+    mailerOptions: {
+      host: 'smtp.126.com',
+      port: 465,
+      secure: true,
+      logger: logger.child({ type: 'mail' }),
+      auth: {
+        user: process.env.MAILER_USER,
+        pass: process.env.MAILER_PASS,
+      },
+    },
  },
  // ...
};
// ...

# .env.local
GITHUB_CLIENT_ID='b8ada004c6d682426cfb'
GITHUB_CLIENT_SECRET='0b13f2ab5651f33f879a535fc2b316c6c731a041'
+
+MAILER_USER='[e-mail]'
+MAILER_PASS='CAEJHSTBWNOKHRVL'

注意由于应用节点可能不止 1 个，执行巡检时将使用分布式锁限制执行节点数量以避免重复报警，这里借助数据库来实现分布式锁：

$ # 生成定时任务锁的 model 文件与 schema 迁移文件
$ yarn sequelize model:generate --name scheduleLock --attributes name:string,counter:integer

$ # 将 src/models/schedulelock.js 命名为 src/models/scheduleLock.js
$ mv src/models/schedulelock.js src/models/scheduleLock.js

$ tree src/models # 展示 src/models 目录内容结构
src/models
├── config
│   └── index.js
├── index.js
├── migrate
│   ├── 20200725045100-create-shop.js
│   ├── 20200727025727-create-session.js
│   └── 20200801120113-create-schedule-lock.js
├── scheduleLock.js
├── seed
│   └── 20200725050230-first-shop.js
└── shop.js

调整 src/models/scheduleLock.js 与 src/models/migrate/20200801120113-create-schedule-lock.js：

// src/models/scheduleLock.js
const { Model } = require('sequelize');

module.exports = (sequelize, DataTypes) => {
  class scheduleLock extends Model {
    /**
     * Helper method for defining associations.
     * This method is not a part of Sequelize lifecycle.
     * The `models/index` file will call this method automatically.
     */
    static associate(models) {
      // define association here
    }
  }
  scheduleLock.init(
    {
      name: DataTypes.STRING,
      counter: DataTypes.INTEGER,
    },
    {
      sequelize,
      modelName: 'ScheduleLock',
      tableName: 'schedule_lock',
    }
  );
  return scheduleLock;
};

// src/models/migrate/20200801120113-create-schedule-lock.js
module.exports = {
  up: async (queryInterface, Sequelize) => {
    await queryInterface.createTable('schedule_lock', {
      id: {
        allowNull: false,
        autoIncrement: true,
        primaryKey: true,
        type: Sequelize.INTEGER,
      },
      name: {
        type: Sequelize.STRING,
      },
      counter: {
        type: Sequelize.INTEGER,
      },
      created_at: {
        allowNull: false,
        type: Sequelize.DATE,
      },
      updated_at: {
        allowNull: false,
        type: Sequelize.DATE,
      },
    });
  },
  down: async (queryInterface, Sequelize) => {
    await queryInterface.dropTable('schedule_lock');
  },
};

然后写入巡检逻辑：

$ mkdir src/schedules # 新建 src/schedules 存放定时任务

$ tree src -L 1       # 展示 src 目录内容结构
src
├── config
├── controllers
├── middlewares
├── models
├── moulds
├── schedules
├── server.js
├── services
└── utils

// src/schedules/inspectAttack.js
const { basename } = require('path');
const schedule = require('node-schedule');
const { sequelize, ScheduleLock, Sequelize } = require('../models');
const mailService = require('../services/mail');
const shopService = require('../services/shop');
const escapeHtmlInObject = require('../utils/escape-html-in-object');
const logger = require('../utils/logger');
const { Op } = Sequelize;

// 当前任务的锁名称
const LOCK_NAME = basename(__dirname);
// 锁的最长占用时间
const LOCK_TIMEOUT = 15 * 60 * 1000;
// 分布式任务并发数
const CONCURRENCY = 1;
// 报警邮件发送对象
const MAIL_RECEIVER = '[e-mail]';

class InspectAttack {
  mailService;
  shopService;

  async init() {
    this.mailService = await mailService();
    this.shopService = await shopService();

    // 每到 15 分时巡检一次
    schedule.scheduleJob('*/15 * * * *', this.findAttackedShopInfoAndSendMail);
  }

  findAttackedShopInfoAndSendMail = async () => {
    // 上锁
    const lockUpT = await sequelize.transaction();
    try {
      const [lock] = await ScheduleLock.findOrCreate({
        where: { name: LOCK_NAME },
        defaults: { name: LOCK_NAME, counter: 0 },
        transaction: lockUpT,
      });

      if (lock.counter >= CONCURRENCY) {
        if (Date.now() - lock.updatedAt.valueOf() > LOCK_TIMEOUT) {
          lock.counter--;
          await lock.save({ transaction: lockUpT });
        }
        await lockUpT.commit();
        return;
      }

      lock.counter++;
      await lock.save({ transaction: lockUpT });
      await lockUpT.commit();
    } catch (err) {
      logger.error(err);
      await lockUpT.rollback();
      return;
    }

    try {
      // 寻找异常数据
      const shops = await this.shopService.find({
        pageSize: 100,
        where: {
          name: { [Op.or]: [{ [Op.like]: '<%' }, { [Op.like]: '%>' }] },
        },
      });

      // 发送报警邮件
      if (shops.length) {
        const subject = '安全警告，发现可疑店铺信息！';
        const html = `
  <div>以下是服务器巡检发现的疑似含有网络攻击的店铺信息：</div>
  <pre>
  ${shops
    .map((shop) => JSON.stringify(escapeHtmlInObject(shop), null, 2))
    .join('\n')}
  </pre>`;
        await this.mailService.sendMail({ to: MAIL_RECEIVER, subject, html });
      }
    } catch {}

    // 解锁
    const lockDownT = await sequelize.transaction();
    try {
      const lock = await ScheduleLock.findOne({
        where: { name: LOCK_NAME },
        transaction: lockDownT,
      });
      if (lock.counter > 0) {
        lock.counter--;
        await lock.save({ transaction: lockDownT });
      }
      await lockDownT.commit();
    } catch {
      await lockDownT.rollback();
    }
  };
}

module.exports = async () => {
  const s = new InspectAttack();
  await s.init();
};

// src/schedules/index.js
const inspectAttackSchedule = require('./inspectAttack');

module.exports = async function initSchedules() {
  await inspectAttackSchedule();
};

// src/server.js
const express = require('express');
const { resolve } = require('path');
const { promisify } = require('util');
const initMiddlewares = require('./middlewares');
const initControllers = require('./controllers');
+const initSchedules = require('./schedules');
const logger = require('./utils/logger');

const server = express();
const port = parseInt(process.env.PORT || '9000');
const publicDir = resolve('public');
const mouldsDir = resolve('src/moulds');

async function bootstrap() {
  server.use(await initMiddlewares());
  server.use(express.static(publicDir));
  server.use('/moulds', express.static(mouldsDir));
  server.use(await initControllers());
  server.use(errorHandler);
+  await initSchedules();
  await promisify(server.listen.bind(server, port))();
  logger.info(`> Started on port ${port}`);
}
// ...

查看报警

在新增两个含有网络攻击的店铺信息之后，即可在分钟数为 15 的倍数时收到一则警告邮件：

本章源码

licg9999/nodejs-server-examples - 11-schedule

更多阅读

从零搭建 Node.js 企业级 Web 服务器（零）：静态服务
从零搭建 Node.js 企业级 Web 服务器（一）：接口与分层
从零搭建 Node.js 企业级 Web 服务器（二）：校验
从零搭建 Node.js 企业级 Web 服务器（三）：中间件
从零搭建 Node.js 企业级 Web 服务器（四）：异常处理
从零搭建 Node.js 企业级 Web 服务器（五）：数据库访问
从零搭建 Node.js 企业级 Web 服务器（六）：会话
从零搭建 Node.js 企业级 Web 服务器（七）：认证登录
从零搭建 Node.js 企业级 Web 服务器（八）：网络安全
从零搭建 Node.js 企业级 Web 服务器（九）：配置项
从零搭建 Node.js 企业级 Web 服务器（十）：日志
从零搭建 Node.js 企业级 Web 服务器（十一）：定时任务
从零搭建 Node.js 企业级 Web 服务器（十二）：远程调用
从零搭建 Node.js 企业级 Web 服务器（十三）：断点调试与性能分析
从零搭建 Node.js 企业级 Web 服务器（十四）：自动化测试
从零搭建 Node.js 企业级 Web 服务器（十五）：总结与展望