Running Selenium tests that require browser interaction on a headless Ubuntu server presents unique challenges. Traditional Selenium RC tests launch actual browser instances, which typically require a display server (X11) and graphical environment. Here's how to achieve this without installing a full desktop environment.
The most efficient approach is using Xvfb (X Virtual Frame Buffer), a display server that performs all graphical operations in memory:
sudo apt-get update
sudo apt-get install -y xvfb firefox
After installing prerequisites, you'll need to set up your test execution environment. Create a shell script to manage the virtual display:
#!/bin/bash
# Start Xvfb
Xvfb :99 -screen 0 1024x768x16 &> /dev/null &
export DISPLAY=:99
# Run your Selenium test
java -jar selenium-server-standalone.jar -htmlSuite "*firefox" "http://your-test-site.com" "/path/to/test-suite.html" "/path/to/results.html"
# Clean up
killall Xvfb
For Python users, here's how to integrate Xvfb with Selenium WebDriver:
from pyvirtualdisplay import Display
from selenium import webdriver
display = Display(visible=0, size=(1024, 768))
display.start()
try:
driver = webdriver.Firefox()
driver.get("http://www.example.com")
# Your test actions here
finally:
driver.quit()
display.stop()
For newer Firefox versions (v56+), you can run in pure headless mode without Xvfb:
from selenium import webdriver
options = webdriver.FirefoxOptions()
options.add_argument('--headless')
driver = webdriver.Firefox(options=options)
driver.get("http://www.example.com")
When running tests on CI servers, consider these optimizations:
- Disable images:
profile.set_preference('permissions.default.image', 2) - Use a RAM disk for temporary files
- Limit browser window size to reduce rendering overhead
If you encounter problems, check these common solutions:
# Ensure proper DISPLAY environment variable
echo $DISPLAY
# Verify Xvfb is running
ps aux | grep Xvfb
# Check Firefox version compatibility
firefox --version
Running Selenium tests that require browser GUIs on a headless Ubuntu server presents unique challenges. The traditional approach of installing full desktop environments like Gnome or KDE defeats the purpose of using lightweight server installations. Here's how to implement a proper headless testing solution.
Xvfb (X Virtual Frame Buffer) provides a perfect solution by creating a virtual display where GUI applications can run without physical hardware:
sudo apt-get install xvfb firefox
Xvfb :99 -ac -screen 0 1024x768x24 &
export DISPLAY=:99
Here's how to launch Selenium Server with the virtual display:
java -jar selenium-server-standalone.jar -firefoxProfileTemplate /path/to/profile
Create a custom Firefox profile for stability:
firefox -CreateProfile seleniumProfile
While Xvfb works well, you might consider more modern alternatives:
sudo apt-get install phantomjs
Here's a full working example using Python and pyvirtualdisplay:
from pyvirtualdisplay import Display
from selenium import webdriver
display = Display(visible=0, size=(1024, 768))
display.start()
try:
driver = webdriver.Firefox()
driver.get("http://www.google.com")
print(driver.title)
finally:
driver.quit()
display.stop()
For even cleaner isolation, consider Docker containers with pre-configured environments:
docker run -d -p 4444:4444 selenium/standalone-firefox
When running headless tests:
- Allocate sufficient memory (at least 1GB for Firefox)
- Disable images for faster execution:
profile.set_preference('permissions.default.image', 2) - Use explicit waits instead of fixed sleeps
Common problems and solutions:
# If getting "no display specified" error:
export DISPLAY=:99
# For Firefox crashes:
sudo apt-get install libdbus-glib-1-2