app.py

import os
import subprocess
import time
import signal
import sys

def run_command(command, background=True):
    print(f"Starting: {command}")
    if background:
        return subprocess.Popen(command, shell=True)
    else:
        return subprocess.run(command, shell=True)

def main():
    # 1. Start Xvfb (Virtual Framebuffer)
    # This creates a virtual display that the browser can draw on.
    resolution = os.environ.get('RESOLUTION', '1280x720')
    xvfb_cmd = f"Xvfb :0 -screen 0 {resolution}x24"
    xvfb_process = run_command(xvfb_cmd)
    
    # Wait for Xvfb to initialize
    time.sleep(2)

    # 2. Start Fluxbox (Window Manager)
    # Essential for handling window placement and maximizing the browser.
    run_command("fluxbox")

    # 3. Start x11vnc
    # Connects the X server to a VNC port (5900).
    run_command("x11vnc -display :0 -forever -shared -rfbport 5900 -nopw")

    # 4. Start websockify (noVNC)
    # Bridges the web browser (WebSocket) to the VNC server (TCP).
    # We serve the default noVNC web files located at /usr/share/novnc.
    novnc_cmd = "websockify --web /usr/share/novnc 7860 localhost:5900"
    run_command(novnc_cmd)

    # 5. Start Brave Browser
    # --kiosk: runs in full screen restricted mode
    # --no-sandbox: required for some docker environments
    # --disable-dev-shm-usage: prevents crashing in containers with low shared memory
    print("Starting Brave Browser...")
    brave_cmd = (
        "brave-browser "
        "--no-sandbox "
        "--disable-dev-shm-usage "
        "--kiosk "
        "--start-maximized "
        "--user-data-dir=/home/user/brave-data "
        "https://www.google.com" # Change this URL to your desired start page
    )
    
    # Run Brave and wait for it. If Brave closes, the container should stop (or restart it).
    # Here we keep the script alive.
    brave_process = subprocess.Popen(brave_cmd, shell=True)

    try:
        # Keep the main thread alive to monitor processes
        while True:
            time.sleep(1)
            if brave_process.poll() is not None:
                print("Brave exited. Restarting...")
                brave_process = subprocess.Popen(brave_cmd, shell=True)
    except KeyboardInterrupt:
        print("Stopping services...")
        xvfb_process.terminate()
        brave_process.terminate()
        sys.exit(0)

if __name__ == "__main__":
    main()