feat: Add session bus option for local testing and development

Introduced a `--use-session-bus` flag to optionally use the D-Bus
session bus instead of the system bus. This allows better flexibility
for local testing and development scenarios without requiring
system-level changes. Updated related classes and functions to respect
the new flag.

src/revpi_middleware/cli_commands/dbus_helper.py

@@ -5,8 +5,9 @@ from threading import Thread
 from time import sleep
 
 from gi.repository import GLib
-from pydbus import SystemBus
+from pydbus import SessionBus, SystemBus
 
+from .. import proginit as pi
 from ..dbus_middleware1 import REVPI_DBUS_BASE_PATH
 from ..dbus_middleware1 import REVPI_DBUS_NAME
 
@@ -34,7 +35,7 @@ def simple_call(method: str, *args, interface: str, object_path=REVPI_DBUS_BASE_
     Any
         The result of the method invocation on the targeted D-Bus interface.
     """
-    bus = SystemBus()
+    bus = SessionBus() if pi.pargs.use_session_bus else SystemBus()
     revpi = bus.get(REVPI_DBUS_NAME, object_path)
     iface = revpi[interface]
     return getattr(iface, method)(*args)
@@ -55,7 +56,7 @@ def await_signal(signal_name: str, timeout: int, interface: str, object_path=REV
         detected_signal = True
         loop.quit()
 
-    bus = SystemBus()
+    bus = SessionBus() if pi.pargs.use_session_bus else SystemBus()
     revpi = bus.get(REVPI_DBUS_NAME, object_path)
     iface = revpi[interface]
 

src/revpi_middleware/daemon.py

@@ -42,7 +42,7 @@ class MiddlewareDaemon:
         if self.bus_provider and self.bus_provider.is_alive():
             return
 
-        self.bus_provider = BusProvider()
+        self.bus_provider = BusProvider(use_system_bus=not pi.pargs.use_session_bus)
         self.bus_provider.start()
 
         log.debug("leave MiddlewareDaemon.dbus_start")

src/revpi_middleware/dbus_middleware1/bus_provider.py

@@ -6,7 +6,7 @@ from logging import getLogger
 from threading import Thread
 
 from gi.repository import GLib
-from pydbus import SystemBus
+from pydbus import SessionBus, SystemBus
 
 from . import REVPI_DBUS_NAME
 from .process_image import InterfacePiControl
@@ -20,11 +20,12 @@ class BusProvider(Thread):
         self,
         picontrol_device="/dev/piControl0",
         config_rsc="/etc/revpi/config.rsc",
+        use_system_bus=True,
     ):
         log.debug("enter BusProvider.__init__")
         super().__init__()
 
-        self._bus = SystemBus()
+        self._bus = SystemBus() if use_system_bus else SessionBus()
         self._loop = GLib.MainLoop()
 
         self.picontrol_device = picontrol_device

src/revpi_middleware/proginit.py

@@ -9,7 +9,7 @@ __version__ = "1.4.0"
 
 import logging
 import sys
-from argparse import ArgumentParser, Namespace
+from argparse import ArgumentParser, Namespace, SUPPRESS
 from configparser import ConfigParser
 from enum import Enum
 from os import R_OK, W_OK, access, environ, getpid, remove
@@ -262,6 +262,16 @@ parser = ArgumentParser(
     prog=programname,
     description="Program description",
 )
+
+# Use session bus of D-Bus for local testing and development proposes (hidden)
+parser.add_argument(
+    "--use-session-bus",
+    dest="use_session_bus",
+    action="store_true",
+    default=False,
+    help=SUPPRESS,
+)
+
 parser.add_argument("--version", action="version", version=f"%(prog)s {program_version}")
 parser.add_argument(
     "-f",