引言

　　当我们接到压测任务的时候，如果被测系统需要登录的时候，首先需要处理登录，然后再进行其他接口压测。

　　Taks属性使用

　　首先看一下官方文档：

　　Using the @task decorator to declare tasks is a convenience, and usually the best way to do it. However, it’s also possible to define the tasks of a User or TaskSet by setting the tasks attribute (using the @task decorator will actually just populate the tasks attribute).

The tasks attribute is either a list of Task, or a <Task : int> dict, where Task is either a python callable or a TaskSet class (more on that below). If the task is a normal python function they receive a single argument which is the User instance that is executing the task.

Here is an example of a User task declared as a normal python function:

from locust import User, constant

def my_task(l):
    pass

class MyUser(User):
    tasks = [my_task]
    wait_time = constant(1)

　　If the tasks attribute is specified as a list, each time a task is to be performed, it will be randomly chosen from the tasks attribute. If however, tasks is a dict - with callables as keys and ints as values - the task that is to be executed will be chosen at random but with the int as ratio. So with a tasks that looks like this:

{my_task: 3, another_task: 1}

　　my_task would be 3 times more likely to be executed than another_task.

Internally the above dict will actually be expanded into a list (and the tasks attribute is updated) that looks like this:

[my_task, my_task, my_task, another_task]

　　and then Python’s random.choice() is used pick tasks from the list.

 

　　上面总结出来就是：如果随机权重，就用列表，如果指定权重，就用字段。

 

　　登录案例

　　普通写法：

from locust import TaskSet,HttpLocust,between

def login(x):
    x.client.post('/login',{'username':'admin','password':'123456'})

def logout(x):
    x.client.post('/logout',{'username':'admin','password':'123456'})

def home(x):
    x.client.get('/')

def systeminfo(x):
    x.client.get('systeminfo')

class TestLogin(TaskSet):

    tasks = {home: 3,systeminfo: 1}

    def on_start(self):
        login(self)

    def on_stop(self):
        logout(self)

class WebSiteUser(HttpLocust):
    task_set = TestLogin
    wait_time = between(3,6)

　　案例

from locust import TaskSet,HttpLocust,between,task

def login(x):
    url = '/api/private/v1/login'
    body = {
        "username": "admin",
        "password": "123456"
    }
    r = x.client.post(url=url, data=body)
    print(r.text)

def logout(x):
    print("退出系统")

def home(x):
    print("进入主页")


def systeminfo(x):
    print("进入系统管理")

class TestLogin(TaskSet):

    tasks = {home: 1,systeminfo: 1}
    # @task
    def setup(self):
        print("开始...")

    def teardown(self):
        print("结束...")

    def on_start(self):
        print("启动")
        login(self)
    # @task
    def on_stop(self):
        print("停止")
        logout(self)


class WebSiteUser(HttpLocust):
    def setup(self):
        print('locust setup')
    def teardown(self):
        print('locust teardown')
    task_set = TestLogin
    wait_time = between(1,2)

if __name__ == '__main__':
    import os
    os.system('locust -f locustfile.py --host=http://192.168.1.105:8899 --port=8089 ')

　　

　　说明：

　　Locust类有setup和teardown，TaskSet类有setup、teardown、on_start、on_stop。

　　每次启动locust时运行setup方法，退出时运行teardown方法，locust执行TaskSet时运行TaskSet的setup方法，退出时运行teardown方法，每个虚拟用户执行操作时运行on_start方法，退出时执行on_stop方法，运行上面的脚本，执行顺序如下：

　　执行顺序：Locust setup → TaskSet setup → TaskSet on_start → TaskSet tasks → TaskSet on_stop → TaskSet teardown → Locust teardown

 

　　运行结果：

[2020-06-22 21:30:10,993] WIN10-804191526/INFO/locust.main: Starting web monitor at http://*:8089
[2020-06-22 21:30:10,993] WIN10-804191526/INFO/locust.main: Starting Locust 0.14.6
[2020-06-22 21:30:20,212] WIN10-804191526/INFO/locust.runners: Hatching and swarming 2 users at the rate 1 users/s (0 users already running)...
[2020-06-22 21:30:20,213] WIN10-804191526/INFO/stdout: locust setup
[2020-06-22 21:30:20,213] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:20,213] WIN10-804191526/INFO/stdout: 开始...
[2020-06-22 21:30:20,213] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:20,213] WIN10-804191526/INFO/stdout: 启动
[2020-06-22 21:30:20,213] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:21,213] WIN10-804191526/INFO/locust.runners: All locusts hatched: WebSiteUser: 2 (0 already running)
[2020-06-22 21:30:21,213] WIN10-804191526/INFO/stdout: 启动
[2020-06-22 21:30:21,213] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:41,220] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:41,220] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:41,220] WIN10-804191526/INFO/stdout: 进入主页
[2020-06-22 21:30:41,220] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:42,217] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:42,217] WIN10-804191526/INFO/stdout: 
[2020-06-22 21:30:42,217] WIN10-804191526/INFO/stdout: 进入系统管理

 

　　界面：