配置定時任務
定時任務也就是由時間觸發的執行過程，屬於很常見的業務邏輯。Unix 在早期版本就提供了定時任務排程模組 Cron，並在各類 Linux 系統上沿用至今。Cron 的配置檔案 crontab 具有全面卻清晰的格式，能夠解決大多數場景下的定時任務配置問題，企業級伺服器可以使用類 crontab 的格式靈活配置的各種定時任務邏輯，以下為 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本章將基於上一章已完成的工程 host1-tech/nodejs-server-examples - 10-log 通過 node-schedule 以類似 crontab 的方式配置定時任務，檢測可能含有網路攻擊的店鋪資訊並通過 nodemailer 將可疑店鋪資訊郵件傳送給管理員。在工程根目錄執行 node-schedule 與 nodemailer 的安裝命令：
$ yarn add node-schedule nodemailer # 本地安裝 node-schedule、nodemailer
# ...
info Direct dependencies
├─ node-schedule@1.3.2
└─ nodemailer@6.4.11
# ...網路攻擊巡檢
現在實現對網路攻擊資訊的定時檢測與報警的邏輯。先補充服務層邏輯：
// 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 = {
// 預設配置
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='ht_nse@126.com'
+MAILER_PASS='CAEJHSTBWNOKHRVL'注意由於應用節點可能不止 1 個，執行巡檢時將使用分散式鎖限制執行節點數量以避免重複報警，這裡藉助資料庫來實現分散式鎖：
$ # 生成定時任務鎖的 model 檔案與 schema 遷移檔案
$ yarn sequelize model:generate --name scheduleLock --attributes name:string,counter:integer
$ # 將 src/models/schedulelock.js 命名為 src/models/scheduleLock.js
$ mv src/models/schedulelock.js src/models/scheduleLock.js
$ tree src/models # 展示 src/models 目錄內容結構
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調整 src/models/scheduleLock.js 與 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');
},
};然後寫入巡檢邏輯：
$ mkdir src/schedules # 新建 src/schedules 存放定時任務
$ tree src -L 1 # 展示 src 目錄內容結構
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;
// 當前任務的鎖名稱
const LOCK_NAME = basename(__dirname);
// 鎖的最長佔用時間
const LOCK_TIMEOUT = 15 * 60 * 1000;
// 分散式任務併發數
const CONCURRENCY = 1;
// 報警郵件傳送物件
const MAIL_RECEIVER = 'licg9999@126.com';
class InspectAttack {
mailService;
shopService;
async init() {
this.mailService = await mailService();
this.shopService = await shopService();
// 每到 15 分時巡檢一次
schedule.scheduleJob('*/15 * * * *', this.findAttackedShopInfoAndSendMail);
}
findAttackedShopInfoAndSendMail = async () => {
// 上鎖
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 {
// 尋找異常資料
const shops = await this.shopService.find({
pageSize: 100,
where: {
name: { [Op.or]: [{ [Op.like]: '<%' }, { [Op.like]: '%>' }] },
},
});
// 傳送報警郵件
if (shops.length) {
const subject = '安全警告，發現可疑店鋪資訊！';
const html = `
<div>以下是伺服器巡檢發現的疑似含有網路攻擊的店鋪資訊：</div>
<pre>
${shops
.map((shop) => JSON.stringify(escapeHtmlInObject(shop), null, 2))
.join('\n')}
</pre>`;
await this.mailService.sendMail({ to: MAIL_RECEIVER, subject, html });
}
} catch {}
// 解鎖
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}`);
}
// ...檢視報警
在新增兩個含有網路攻擊的店鋪資訊之後，即可在分鐘數為 15 的倍數時收到一則警告郵件：
本章原始碼
host1-tech/nodejs-server-examples - 11-schedule
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