Locust性能测试3--参数化、数据依赖

场景链路压测的时候通常都是按照用户实际使用流程进行压测，同接口自动化一样，一定会涉及到数据依赖的问题

1.举例

• Django后台通常需要csrf验证，而一般csrftoken需要通过get接口获得

from locust import HttpUser, task, between
from lxml import etree

USER_CREDENTIALS = [
    ("login1", "pwd1"),
    ("login2", "pwd2"),
    ("login3", "pwd3"),
]  # 登录账户

csrf_token = []

class LoginDemo(HttpUser):
    wait_time = between(2, 5)  # 模拟用户等待2到5s然后执行

    @task(1)
    def on_start(self):  # 任务开始时准备
        header = {
            "User-Agent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) "
                          "Chrome/83.0.4103.61 Safari/537.36 "
        }  # 请求头

        # 获取csrf
        r_get = self.client.get("user/login/")

        # 从返回的html页面中，解析出 csrfmiddlewaretoken
        dom = etree.HTML(r_get.content.decode("utf-8"))
        try:
            csrf_token['csrfmiddlewaretoken'] = dom.xpath('//input[@name="csrfmiddlewaretoken"]')[0].get("value")
            print(csrf_token)
        except:
            print('参数csrfmiddlewaretoken获取失败！')

        if len(USER_CREDENTIALS) > 0:
            user, pwd = USER_CREDENTIALS.pop()  # 取出账户名密码

            r_post = self.client.post("user/login/", {
                "token": 'TOKEN',  # TOKEN
                "username": user,  # 用户名
                "password": pwd,  # 密码
                "next": ""
            }, header=header
                                      )

            assert r_post.status_code == 200  # 断言请求返回200

            print(r_post.status_code, r_post.text[:1000])  # 打印状态码及返回text

    @task(2)
    def view_index(self):
        print('访问首页')
        r = self.client.get("/index/")

        print(r.status_code)

    @task(6)
    def view_tag(self):
        print('访问标签页')
        r = self.client.get("/tag/")

        print(r.status_code)

if __name__ == "__main__":
    import os

    os.system("locust -f demo.py --host=URL")  # 需要测试的地址

• 这里我们使用了etree 来获取get接口返回的数据

2.更新请求头

self.client.headers.update(header)

3. 数据依赖

• 转化接口返回数据，然后获得

import json

@task(2)
def view_index(self):
      r = self.client.get("/index/")
      response = json.loads(r.text)
      demo = response['取值']  # 假如取demo
      print("===>", response['取值'], type(response))  # 取值

      self.client.get('index/url/{}/'.format(demo))

4. 小结

• 可以先看一下request库 ，涉及到数据依赖的问题更好学习
  
  https://yiluotalk.com/2019/12/19/Python%20requests%E5%BA%93(%E4%B8%80)/