Docker containers for test execution in Selenium Python - Test Execution Trace

Test Overview

This test opens a web page inside a Docker container running Selenium WebDriver. It verifies the page title to confirm the browser inside the container works correctly.

Test Code - unittest

Selenium Python

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.chrome.options import Options
import unittest

class TestDockerSelenium(unittest.TestCase):
    def setUp(self):
        chrome_options = Options()
        chrome_options.add_argument('--headless')
        chrome_options.add_argument('--no-sandbox')
        chrome_options.add_argument('--disable-dev-shm-usage')
        self.driver = webdriver.Remote(
            command_executor='http://localhost:4444/wd/hub',
            options=chrome_options
        )

    def test_open_example(self):
        self.driver.get('https://example.com')
        title = self.driver.title
        self.assertEqual(title, 'Example Domain')

    def tearDown(self):
        self.driver.quit()

if __name__ == '__main__':
    unittest.main()

Execution Trace - 4 Steps

Step	Action	System State	Assertion	Result
1	Test starts and sets up Selenium WebDriver to connect to Docker container at localhost:4444	Docker container with Selenium Grid is running and ready to accept connections	-	PASS
2	Browser inside Docker container opens URL 'https://example.com'	Browser navigates to example.com page inside container	-	PASS
3	Test retrieves the page title from the browser	Page title is 'Example Domain'	Check if page title equals 'Example Domain'	PASS
4	Test closes the browser and ends session	Browser session inside Docker container is closed	-	PASS

Failure Scenario

Failing Condition: Docker container with Selenium is not running or unreachable at localhost:4444

Execution Trace Quiz - 3 Questions

What does the test verify inside the Docker container?

A The page URL contains 'docker'

B The page title is 'Example Domain'

C The browser version is Chrome

D The container has internet access

Key Result

Using Docker containers for test execution isolates browser environments, making tests consistent and easy to run on any machine without local browser setup.