Kiosk development environment for macOS

.github/workflows/test.yml

@@ -43,6 +43,22 @@ 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
+    - uses: DeterminateSystems/magic-nix-cache-action@v4
+    - name: Smoke Test
+      run: cd kiosk && nix-shell ./macos/shell.nix --run "python test/platform-smoke.py"
+
   build-vm:
     runs-on: ubuntu-latest
     steps:

kiosk/Readme.md

@@ -4,7 +4,10 @@ Cycle between two urls in a full screen, locked down browser based on [QtWebEngi
 
 ## Development
 
-Run `nix-shell` to create a suitable development environment.
+### Setup environment
+
+- On Linux: `nix-shell`
+- On macOS: `nix-shell ./macos/shell.nix` 
 
 Then, start the kiosk browser with, for example:
 
@@ -28,3 +31,9 @@ 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/browser_widget.py

@@ -3,8 +3,7 @@
 import logging
 import re
 import time
-
-from kiosk_browser import system
+from kiosk_browser.system import System
 
 # Config
 reload_on_network_error_after = 5000 # ms
@@ -19,7 +18,7 @@ class Status(Enum):
 
 class BrowserWidget(QtWidgets.QWidget):
 
-    def __init__(self, url, get_current_proxy, parent):
+    def __init__(self, url, get_current_proxy, parent, system: System):
         QtWidgets.QWidget.__init__(self, parent)
         self.setStyleSheet(f"background-color: white;")
 
@@ -47,8 +46,7 @@ def __init__(self, url, get_current_proxy, parent):
         # Override user agent
         self._webview.page().profile().setHttpUserAgent(user_agent_with_system(
             user_agent = self._webview.page().profile().httpUserAgent(),
-            system_name = system.NAME,
-            system_version = system.VERSION
+            system = system,
         ))
 
         # Allow sound playback without user gesture
@@ -139,20 +137,21 @@ def _view(self, status):
             self._webview.show()
             self._webview.setFocus()
 
-def user_agent_with_system(user_agent, system_name, system_version):
+def user_agent_with_system(user_agent: str, system: System):
     """Inject a specific system into a user agent string"""
     pattern = re.compile('(Mozilla/5.0) \(([^\)]*)\)(.*)')
     m = pattern.match(user_agent)
 
-    if m == None:
-        return f"{system_name}/{system_version} {user_agent}"
-    else:
-        if not m.group(2):
-            system_detail = f"{system_name} {system_version}"
-        else:
-            system_detail = f"{m.group(2)}; {system_name} {system_version}"
+    match m:
+        case None:
+            return f"{system.name}/{system.version} {user_agent}"
+        case m:
+            if not m.group(2):
+                system_detail = f"{system.name} {system.version}"
+            else:
+                system_detail = f"{m.group(2)}; {system.name} {system.version}"
 
-        return f"{m.group(1)} ({system_detail}){m.group(3)}"
+            return f"{m.group(1)} ({system_detail}){m.group(3)}"
 
 def loading_page(parent):
     """ Show a loader in the middle of a blank page.

kiosk/kiosk_browser/dbus_proxy.py

@@ -0,0 +1,160 @@
+"""Monitor proxy changes and automatically apply changes in Qt application.
+"""
+
+import collections
+import dbus
+import logging
+import threading
+import urllib
+from PyQt6.QtNetwork import QNetworkProxy
+from dataclasses import dataclass
+from dbus.mainloop.glib import DBusGMainLoop
+from gi.repository import GLib
+from kiosk_browser.proxy import Proxy, ProxyConf, Credentials
+
+@dataclass
+class Service:
+    state: str
+    proxy: ProxyConf | None
+
+def parse_service(service: dbus.Struct) -> Service | None:
+    if len(service) >= 2 and 'State' in service[1]:
+        return Service(service[1]['State'], extract_manual_proxy(service[1]))
+    else:
+        return None
+
+def extract_manual_proxy(service_conf: dbus.Dictionary) -> ProxyConf | None:
+    if 'Proxy' in service_conf:
+        proxy = service_conf['Proxy']
+        if 'Method' in proxy and 'Servers' in proxy:
+            method = proxy['Method']
+            servers = proxy['Servers']
+            if method == 'manual' and len(servers) >= 1:
+                return parse_proxy_url(servers[0])
+            else:
+                return None
+        else:
+            return None
+    else:
+        return None
+
+def parse_proxy_url(url: str) -> ProxyConf | None:
+    if url.startswith('http://'):
+        parsed = urllib.parse.urlparse(url)
+    else:
+        parsed = urllib.parse.urlparse(f'http://{url}')
+
+    if parsed.hostname != None and parsed.port != None:
+        assert isinstance(parsed.hostname, str)
+        assert isinstance(parsed.port, int)
+
+        if parsed.username != None and parsed.password != None:
+            assert isinstance(parsed.username, str)
+            assert isinstance(parsed.password, str)
+
+            username = urllib.parse.unquote(parsed.username)
+            password = urllib.parse.unquote(parsed.password)
+            return ProxyConf(parsed.hostname, parsed.port, Credentials(username, password))
+        else:
+            return ProxyConf(parsed.hostname, parsed.port, None)
+    else:
+        logging.warning(f"Hostname or port missing in proxy url")
+        return None
+
+def get_current_proxy(bus) -> ProxyConf | None:
+    """Get current proxy from dbus.
+
+    Return the proxy of a connected service preferentially, or of a ready
+    service.
+
+    Return None if Connman is not installed (DBusException).
+    """
+
+    try:
+        client = dbus.Interface(
+            bus.get_object('net.connman', '/'),
+            'net.connman.Manager')
+
+        # List services, each service is a (id, properties) struct
+        services = [parse_service(s) for s in client.GetServices()]
+
+        # The service with the default route will always be sorted at the top of
+        # the list. (From connman doc/overview-api.txt)
+        default_service = find(lambda s: s.state in ['online', 'ready'], services)
+
+        if default_service:
+            return default_service.proxy
+        else:
+            return None
+
+    except dbus.exceptions.DBusException:
+        return None
+
+def find(f, xs):
+    return next((x for x in xs if f(x)), None)
+
+def set_proxy_in_qt_app(hostname, port):
+    logging.info(f"Set proxy to {hostname}:{port} in Qt application")
+    network_proxy = QNetworkProxy()
+    network_proxy.setType(QNetworkProxy.HttpProxy)
+    network_proxy.setHostName(hostname)
+    network_proxy.setPort(port)
+    QNetworkProxy.setApplicationProxy(network_proxy)
+
+def set_no_proxy_in_qt_app():
+    logging.info(f"Set no proxy in Qt application")
+    QNetworkProxy.setApplicationProxy(QNetworkProxy())
+
+
+
+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)
+
+    def start_monitoring_daemon(self):
+        """Use initial proxy in Qt application and watch for changes."""
+        self._use_in_qt_app()
+        thread = threading.Thread(target=self._monitor, args=[])
+        thread.daemon = True
+        thread.start()
+
+    def _monitor(self):
+        self._bus.add_signal_receiver(
+            handler_function = self._on_property_changed,
+            bus_name = 'net.connman',
+            member_keyword = 'PropertyChanged')
+
+        # Update just after monitoring is on, so that we do not miss any proxy
+        # modification that could have happen before.
+        self._update(get_current_proxy(self._bus))
+
+        loop = GLib.MainLoop()
+        loop.run()
+
+    def _on_property_changed(self, *args, **kwargs):
+        if len(args) >= 2 and args[0] == 'Proxy':
+            self._update(get_current_proxy(self._bus))
+
+    def _update(self, new_proxy):
+        """Update the proxy and use in Qt application, if the value has changed."""
+        if new_proxy != self._proxy:
+            self._proxy = new_proxy
+            self._use_in_qt_app()
+
+    def _use_in_qt_app(self):
+        if self._proxy is not None:
+            set_proxy_in_qt_app(self._proxy.hostname, self._proxy.port)
+        else:
+            set_no_proxy_in_qt_app()

kiosk/kiosk_browser/main_widget.py

@@ -1,6 +1,8 @@
 from PyQt6 import QtWidgets, QtCore, QtGui
 
-from kiosk_browser import browser_widget, captive_portal, dialogable_widget, proxy as proxy_module
+from kiosk_browser import browser_widget, captive_portal, dialogable_widget
+from kiosk_browser.system import System
+import platform
 
 class MainWidget(QtWidgets.QWidget):
     """ Show website at kiosk_url.
@@ -13,8 +15,17 @@ class MainWidget(QtWidgets.QWidget):
     def __init__(self, kiosk_url: str, settings_url: str, toggle_settings_key: str):
         super(MainWidget, self).__init__()
 
+        if platform.system() in ['Darwin']:
+            from kiosk_browser.proxy import Proxy
+            import os
+            system = System(name = "PlayOS",
+                            version = os.getenv("PLAYOS_VERSION","1.0.0-dev"))
+        else:
+            from kiosk_browser.dbus_proxy import DBusProxy as Proxy
+            system = System()
+
         # Proxy
-        proxy = proxy_module.Proxy()
+        proxy = Proxy()
         proxy.start_monitoring_daemon()
 
         # Browser widget
@@ -25,7 +36,8 @@ def __init__(self, kiosk_url: str, settings_url: str, toggle_settings_key: str):
             inner_widget = browser_widget.BrowserWidget(
                 url = kiosk_url,
                 get_current_proxy = proxy.get_current,
-                parent = self),
+                parent = self,
+                system = system),
             on_close = self._close_dialog)
 
         # Captive portal