Allow using the kiosk on platforms without DBus

.github/workflows/test.yml

@@ -43,6 +43,21 @@ jobs:
     - uses: DeterminateSystems/magic-nix-cache-action@v4
     - run: cd kiosk && nix-shell --run bin/test
 
+  kiosk-platform-smoke-test:
+    # While the smoke test should run on other platforms, it does not currently
+    # run on GitHub's Ubuntu runners, as they don't support GUI applications.
+    runs-on: macos-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v2
+      with:
+        python-version: '3.8'
+    - uses: cachix/install-nix-action@v18
+      with:
+        nix_path: nixpkgs=channel:nixos-unstable
+    - name: Smoke Test
+      run: cd kiosk && nix-shell --run "python test/platform-smoke.py"
+
   build-vm:
     runs-on: ubuntu-latest
     steps:

kiosk/Readme.md

@@ -28,3 +28,9 @@ Then, point a Chromium-based browser to `http://127.0.0.1:3355`.
 
 Additional documentation is available at:
 https://doc.qt.io/qt-6/qtwebengine-debugging.html
+
+## Supported platforms
+
+The kiosk is written with use within PlayOS in mind (implying connman and DBus as part of the system). To allow for testing web pages in the kiosk on developer machines, macOS is also supported, with the following limitations:
+
+- No proxy server support

kiosk/default.nix

@@ -42,10 +42,5 @@ python3Packages.buildPythonApplication rec {
   shellHook = ''
     # Give access to kiosk_browser module
     export PYTHONPATH=./:$PYTHONPATH
-
-    # Setup Qt environment
-    bashdir=$(mktemp -d)
-    makeWrapper "$(type -p bash)" "$bashdir/bash" "''${qtWrapperArgs[@]}"
-    exec "$bashdir/bash"
   '';
 }

kiosk/kiosk_browser/main_widget.py

@@ -14,7 +14,7 @@ def __init__(self, kiosk_url: str, settings_url: str, toggle_settings_key: str):
         super(MainWidget, self).__init__()
 
         # Proxy
-        proxy = proxy_module.Proxy()
+        proxy = proxy_module.init()
         proxy.start_monitoring_daemon()
 
         # Browser widget

kiosk/kiosk_browser/proxy.py

@@ -4,6 +4,7 @@
 import collections
 import dbus
 import logging
+import platform
 import threading
 import urllib
 from PyQt6.QtNetwork import QNetworkProxy
@@ -115,9 +116,47 @@ def set_no_proxy_in_qt_app():
     logging.info(f"Set no proxy in Qt application")
     QNetworkProxy.setApplicationProxy(QNetworkProxy())
 
-class Proxy():
+def init():
+    """Initialize a suitable Proxy instance for the current platform."""
+    if platform.system() in ['Linux']:
+        return DBusProxy()
+    else:
+        return Proxy()
+
+class Proxy:
+    """Base class for proxy querying.
+
+    The base class does not know how to query for proxy information and may be used as a fallback that always reports that no proxy is configured.
+    """
+    _proxy: ProxyConf | None
+
+    # For the base class, this is a pass, not knowing how to monitor in the general case.
+    def start_monitoring_daemon(self) -> None:
+        """Start a daemon monitoring for proxy changes.
+
+        In the base class, no monitoring method is known, and starting a daemon is skipped.
+        """
+        pass
+
+    def get_current(self) -> ProxyConf | None:
+        """Get the currently configured proxy.
+
+        This is always `None` in the base class.
+        """
+        return self._proxy
+
+class DBusProxy(Proxy):
+    """A Proxy class for DBus/Linux systems.
+
+    This class assumes that connman is the network manager and that it can be queried via DBus.
+    """
+
+    _proxy: ProxyConf | None
+    _bus: dbus.SystemBus
 
     def __init__(self):
+        super().__init__()
+
         DBusGMainLoop(set_as_default=True)
         self._bus = dbus.SystemBus()
         self._proxy = get_current_proxy(self._bus)
@@ -129,9 +168,6 @@ def start_monitoring_daemon(self):
         thread.daemon = True
         thread.start()
 
-    def get_current(self):
-        return self._proxy
-
     def _monitor(self):
         self._bus.add_signal_receiver(
             handler_function = self._on_property_changed,

kiosk/test/platform-smoke.py

@@ -0,0 +1,65 @@
+import http.server
+import socket
+import socketserver
+import threading
+import subprocess
+import time
+
+PORT = 45678
+request_count = 0
+
+def main():
+    """Checks that the kiosk-browser does not crash immediately on start and makes a request to the provided URL.
+
+    This serves as a minimal test to make sure the kiosk can run on different platforms.
+    """
+
+    # Start dummy web server in thread, with signal to stop
+    keep_running = threading.Event()
+    keep_running.set()
+    server_thread = threading.Thread(target=run_server, args=(keep_running,))
+    server_thread.start()
+    time.sleep(1)
+
+    try:
+        browser_process = subprocess.Popen(['bin/kiosk-browser', f'http://localhost:{PORT}', f'http://localhost:{PORT}'])
+        time.sleep(5)
+
+        # Minimal expectations
+        assert browser_process.poll() is None, "Browser process has crashed."
+        assert request_count >= 1, "No requests were made to the server."
+
+        print("Smoke test passed successfully.")
+
+    finally:
+        # Send signal to stop web server and wait for completion
+        keep_running.clear()
+        server_thread.join()
+
+        # Terminate the browser process
+        browser_process.terminate()
+
+class RequestHandler(http.server.SimpleHTTPRequestHandler):
+    """Default request handler with added counter."""
+    def do_GET(self):
+        global request_count
+        request_count += 1
+        # Call superclass method to actually serve the request
+        super().do_GET()
+
+def run_server(keep_running):
+    """Run the web server, checking whether to keep running frequently."""
+    with socketserver.TCPServer(("", PORT), RequestHandler, bind_and_activate=False) as httpd:
+        # Let address be reused to avoid failure on repeated runs
+        httpd.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        httpd.server_bind()
+        httpd.server_activate()
+        # Timeout frequently to check if killed
+        httpd.timeout = 0.5
+        try:
+            while keep_running.is_set():
+                httpd.handle_request()
+        finally:
+            httpd.server_close()
+
+main()