Chrome extension tests failing in GitLab CI pipeline due to headless mode limitations

Need help with browser extension testing in CI environment

I’m working on automated tests that require loading a Chrome extension. The problem is that I need to run these tests in my GitLab CI pipeline, but headless Chrome doesn’t work with extensions from what I’ve found.

Switching to Firefox isn’t an option since my extension only works with Chrome. Has anyone figured out how to run extension-based tests in GitLab CI?

I came across something called xvfb virtual display while researching, but I’m not sure if that would solve my problem or how to implement it properly in GitLab. My attempts so far haven’t been successful.

Any suggestions would be really appreciated!

The Problem:

You’re trying to run automated tests for a Chrome extension within your GitLab CI pipeline, but headless Chrome doesn’t support extensions. Switching browsers isn’t feasible because your extension is Chrome-specific. You’ve explored xvfb, but haven’t achieved success.

:thinking: Understanding the “Why” (The Root Cause):

Headless Chrome, designed for speed and minimal resource usage, omits features like extension support to reduce overhead. xvfb (X virtual framebuffer) simulates a display, enabling you to run a “headed” (GUI-based) Chrome instance within a headless environment like your CI pipeline. The challenge lies in the complexities of coordinating xvfb startup, Chrome configuration (including extension loading), and test execution within the constraints of your CI system. Manual configuration is often fragile and prone to breakage with Chrome updates.

:gear: Step-by-Step Guide:

This guide focuses on automating the process to ensure robustness and reliability. The core idea is to create a streamlined workflow that handles all aspects of the testing process, from environment setup to teardown. This approach eliminates the need for complex and brittle manual configuration.

Step 1: Automate the Entire Workflow

Instead of manually managing xvfb and Chrome configuration in your GitLab CI YAML file, automate the entire process. This involves creating a script or program (in Python, Bash, etc.) that handles the following actions sequentially:

  1. Start xvfb: Initiate the virtual display with appropriate settings (resolution, etc.). Error handling is crucial here; the script should check for successful startup.
  2. Configure and Launch Chrome: Launch Chrome with the necessary flags, including the path to your extension. The --remote-debugging-port flag is highly recommended for better control and debugging. Example flags might include --no-sandbox, --disable-dev-shm-usage, --disable-gpu.
  3. Load the Extension: Ensure your extension is correctly loaded in the Chrome instance.
  4. Run Your Tests: Execute your test suite.
  5. Clean Up: Shut down Chrome and xvfb gracefully, even if tests fail. This prevents resource leaks and keeps your CI environment clean.

Example (Conceptual Python Script):

import subprocess
import time

def run_tests():
    # ... your test execution logic here ...

def main():
    # Start xvfb
    xvfb_process = subprocess.Popen(["Xvfb", ":99", "-screen", "0", "1920x1080x24"])
    time.sleep(5) # Allow xvfb to start

    # Launch Chrome with extension and remote debugging
    chrome_process = subprocess.Popen(["google-chrome", "--remote-debugging-port=9222", "--load-extension=/path/to/your/extension", "--no-sandbox", "--disable-dev-shm-usage", "--disable-gpu", "--window-size=1920,1080", "--window-position=0,0"])

    try:
        run_tests()
    except Exception as e:
        print(f"Tests failed: {e}")
    finally:
        chrome_process.terminate()
        xvfb_process.terminate()
        print("Chrome and Xvfb terminated.")


if __name__ == "__main__":
    main()

Step 2: Integrate into GitLab CI

Integrate your automation script into your GitLab CI configuration file (.gitlab-ci.yml). This file will trigger the script during your pipeline. Your script should be included in your repository.

Step 3: Consider Containerization (Docker)

For enhanced isolation and reproducibility, containerize your entire testing environment using Docker. This eliminates dependency conflicts and ensures consistency across environments.

:mag: Common Pitfalls & What to Check Next:

  • Insufficient xvfb Startup Time: Ensure enough time is allowed for xvfb to initialize before Chrome launches.
  • Incorrect Extension Path: Double-check the path to your Chrome extension in your Chrome launch command.
  • Missing Dependencies: Make sure all necessary dependencies (e.g., xvfb, Chrome, your testing framework) are installed and accessible.
  • Permission Issues: Verify that your user has the appropriate permissions to run xvfb and launch Chrome.
  • Chrome Version Compatibility: Ensure that your Chrome version is compatible with your extension and testing framework.

:speech_balloon: Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!

Docker saved me so much headache here. Instead of wrestling with xvfb config in GitLab runners, I just containerized everything. Grab an Ubuntu base image that’s got Chrome and xvfb already baked in, then GitLab CI just runs the container. The game-changer was setting up the container to auto-start xvfb in the background before Chrome kicks off. No more timing nightmares where Chrome tries launching before the virtual display is ready. I baked the extension loading and environment variables right into the dockerfile, so the CI pipeline stays super clean - just docker run and go. Way more reliable than trying to juggle xvfb startup in those GitLab yaml files. Plus you can spin up the exact same environment locally for debugging.

Hit this exact problem six months back when moving our extension tests to CI. Everyone suggests xvfb but I found something that works way better. Skip the virtual display headache. Just use Chrome with --no-sandbox, --disable-dev-shm-usage, and --disable-gpu but keep it headed. Set DISPLAY to :99 and wrap your test command with xvfb-run. The game changer? Add --remote-debugging-port=9222 to Chrome’s flags. This totally fixed the extension loading weirdness in CI. Now my GitLab job fires up xvfb in the background, waits a couple seconds, then runs tests like normal. Turns out you don’t need fancy xvfb configs - basic setup plus the right Chrome flags does it. Been rock solid for months, way better than those headless hacks I wasted time on.

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