Load testing by Python Locust

Locust 介紹

An open source load testing tool. Define user behaviour with Python code, and swarm your system with millions of simultaneous users.

pip install locust

Write a locust script

from locust import HttpUser, task, between
import json
from test_data import *
import random


class WebsiteTestUser(HttpUser):
    wait_time = between(0.5, 1)
    host = "http://host_address"

    def on_start(self):
        """ on_start is called when a Locust start before any task is scheduled """
        if len(USER_CREDENTIALS) > 0:
            account, password = USER_CREDENTIALS.pop()
            self.access, self.refresh = self.login_to_get_token(account, password)

    def on_stop(self):
        """ on_stop is called when the TaskSet is stopping """
        pass

    def login_to_get_token(self, account, password):
        path = '/login'
        headers = {'Content-Type': 'application/json'}
        payload = {
            "email": account,
            "password": password
        }
        resp = self.client.post(url=path, headers=headers, data=json.dumps(payload))

        return resp.json()['access_token'], resp.json()['refresh_token']

    def refresh_token(self, token):
        url = "/refreshToken"
        headers = {'Content-Type': 'application/json'}
        payload = {"refresh_token": token}
        resp = self.client.post(url, headers=headers, data=json.dumps(payload))
        self.access = resp.json()['access_token']
        self.refresh = resp.json()['refresh_token']

    @task(1)
    def get_file(self):
        uuid_list = [
            '7ca74e17-ac8a-48fc-84ed-0e947cb4c333',
            '666e4a5b-6704-41e9-b08d-b18dd1d50c0f',
            'c8c17345-d533-41b0-bbd5-5e39d023fcb6',
        ]
        path = f'/files/{random.choice(uuid_list)}'
        headers = {'Content-Type': 'application/json', 'Authorization': f'Bearer {self.access}'}
        with self.client.get(url=path, headers=headers, catch_response=True) as response:
            if response.status_code == 401 and response.json()['status'] == "UnauthorizedError":
                self.refresh_token(self.refresh)

from locust import HttpUser, task, between
import json
from test_data import *
import random

class WebsiteTestUser(HttpUser):
    wait_time = between(0.5, 1)

@task(1)
def get_file(self):
    ...
    with self.client.get(url=path, headers=headers, catch_response=True) as response:
    ...

Run the script with GUI

locust -f locust_file.py

Running without the web UI

locust -f locust_file.py --headless -u 5 -r 1 -t 360s --html test_report.html

locust --config=/load_testing/config.conf

locustfile = /load_testing/locust_file.py
headless = true
host = http://example.com
users = 10
spawn-rate = 1
run-time = 10s
html = locust_report.html

Trigger locust test with Gitlab CI

locustfile = /builds/project_name/load_testing/RUN_TARGET.py
headless = true
host = https://example.com
users = RUN_USERS
spawn-rate = 1
run-time = RUN_TIME
html = locust_report.html

stages:
  - test
locust:
  stage: test
  variables:
    TARGET: ""
    USERS: "1"
    TIME: "10s"
  before_script:
    - cat /builds/project_name/load_testing/__locust.conf
    - sed -e 's/RUN_TARGET/'$TARGET'/1' -e 's/RUN_USERS/'$USERS'/1' -e 's/RUN_TIME/'$TIME'/1' /builds/project_name/load_testing/__locust.conf > /builds/project_name/load_testing/locust_run.conf
    - cat /builds/project_name/load_testing/locust_run.conf
  script:
    - locust --config=/builds/project_name/load_testing/locust_run.conf
  rules:
    - if: $TARGET
  allow_failure: true
  artifacts:
    when: always
    paths:
      - locust_report.html
    expire_in: 1 week

stages:
  - test
locust:
  stage: test
  image: /runner-image/qa-python:3.7.7-20220719
  variables:
    GIT_SSL_NO_VERIFY: "1"
  script:
    - locust -f load_testing/test1.py --headless -u 10 -r 1 -t 360s --html report1.html
    - locust -f load_testing/test2.py --headless -u 10 -r 1 -t 360s --html report2.html
    - locust -f load_testing/test3.py --headless -u 10 -r 1 -t 360s --html report3.html
  rules:
    - changes:
        - requirements.txt
  allow_failure: true
  artifacts:
    when: always
    paths:
      - report1.html
      - report2.html
      - report3.html
    expire_in: 1 week

總結