[Day26][負載測試] K6 使用上常見的套件(module)有哪些？

2022 iThome 鐵人賽

DAY 26

Software Development

QA 三十天養成日記系列第 26 篇

14th鐵人賽 qa k6 負載測試壓力測試

Gary

2022-10-10 10:53:37

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K6 套件(module) 基本上我覺得很萬用，是足夠支撐所有測試情境的。
也主要介紹幾個較常用的 K6 本身支援的 module (JavaScript API)

http

主要是能發送 API，常使用為 get/post/put/del

GET code sample

import http from 'k6/http';
export const options = {
  vus: 1,
  duration: '1s',
};

export default function () {
  http.get('https://test.k6.io');
}

POST code sample

import http from 'k6/http';

const url = 'https://httpbin.test.k6.io/post';
const logoBin = open('./logo.png', 'b');
export default function () {
  let data = { name: 'Bert' };

  // Using a JSON string as body
  let res = http.post(url, JSON.stringify(data), {
    headers: { 'Content-Type': 'application/json' },
  });
  console.log(res.json().json.name); // Bert

  // Using an object as body, the headers will automatically include
  // 'Content-Type: application/x-www-form-urlencoded'.
  res = http.post(url, data);
  console.log(res.json().form.name); // Bert

  // Using a binary array as body. Make sure to open() the file as binary
  // (with the 'b' argument).
  http.post(url, logoBin, { headers: { 'Content-Type': 'image/png' } });

  // Using an ArrayBuffer as body. Make sure to pass the underlying ArrayBuffer
  // instance to http.post(), and not the TypedArray view.
  data = new Uint8Array([104, 101, 108, 108, 111]);
  http.post(url, data.buffer, { headers: { 'Content-Type': 'image/png' } });
}

html

解析 HTML 各元素，可能會需要取得 HTML 上的一些元素值做一些處理或換算。

code sample

import http from 'k6/http';

export default function () {
  const res = http.get('https://k6.io');
  const doc = parseHTML(res.body); // equivalent to res.html()
  const pageTitle = doc.find('head title').text();
  const langAttr = doc.find('html').attr('lang');
}

sleep

主要就是等待時間，有些時候使用 sleep 是為了更好模擬使用者情境
因為使用者真實操作 web 可能都會遇到有 loading 渲染的時間，所以我們將 sleep 算進來的話就當作是再重現這部分。

import http from 'k6/http';
import { sleep } from 'k6';
export const options = {
  vus: 1,
  duration: '1s',
};

export default function () {
  http.get('https://test.k6.io');
  sleep(1);
}

crypto

這一定也不陌生，非常強大的加密 module ，支援多種不同的加密方式如下:

hmac
md4
md5
sha256
sha384
sha512

通常是為了確保用戶資料安全而特別處理的。e.g. 密碼、API header 等

import crypto from 'k6/crypto';

export default function () {
  console.log(crypto.sha256('hello world!', 'hex'));
  const hasher = crypto.createHash('sha256');
  hasher.update('hello ');
  hasher.update('world!');
  console.log(hasher.digest('hex'));
}

Respone

INFO[0000] 7509e5bda0c762d2bac7f90d758b5b2263fa01ccbc542ab5e3df163be08e6ca9

encoding

import { check } from 'k6';
import encoding from 'k6/encoding';

export default function () {
  const str = 'hello world';
  const enc = 'aGVsbG8gd29ybGQ=';
  const buf = new Uint8Array([104, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]).buffer;
  check(null, {
    'is encoding string correct': () => encoding.b64encode(str) === enc,
    'is encoding ArrayBuffer correct': () => encoding.b64encode(buf) === enc,
  });
}

JSlib

k6本身支援蠻多受用的套件，但除此之外，他們還有支援一個是 JSlib 顧名思義就是 JS 庫
我覺得可以把它當作是外掛包因為其中還支援的很多額外的 module 可用。

但我不確定為什麼 k6 不把它納入官方的套件，卻須要用一個外掛包就是了XDD

httpx: 是將 k6/http 原本套件加以簡化處理，可以當成是優化版的 http

k6chaijs: 適用於 BDD 和 TDD 斷言風格

import { describe, expect } from 'https://jslib.k6.io/k6chaijs/4.3.4.1/index.js';
import http from 'k6/http';

export const options = {
  thresholds: {
    checks: [{ threshold: 'rate == 1.00' }], // fail test on any expect() failure
  },
};

export default function testSuite() {
  describe('Basic API test', () => {
    const response = http.get('https://test-api.k6.io/public/crocodiles');
    expect(response.status, 'API status code').to.equal(200);
  });
}

utils: k6 的小工具包

import { sleep } from 'k6';
import http from 'k6/http';

import {
  randomIntBetween,
  randomString,
  randomItem,
  uuidv4,
  findBetween,
} from 'https://jslib.k6.io/k6-utils/1.2.0/index.js';

export default function () {
  const res = http.post(`https://test-api.k6.io/user/register/`, {
    first_name: randomItem(['Joe', 'Jane']), // random name
    last_name: `Jon${randomString(1, 'aeiou')}s`, //random character from given list
    username: `user_${randomString(10)}@example.com`, // random email address,
    password: uuidv4(), // random password in form of uuid
  });

  // find a string between two strings to grab the username:
  const username = findBetween(res.body, '"username":"', '"');
  console.log('username from response: ' + username);

  sleep(randomIntBetween(1, 5)); // sleep between 1 and 5 seconds.
}