feat: Upgrade proginit to version 1.3.0

src/revpicommander/__main__.py

@@ -17,14 +17,14 @@ if __package__ == "":
 if __name__ == "__main__":
     import sys
 
-    if len(sys.argv) == 2 and "--version" in sys.argv:
+    try:
-        # Catch --version, if this is the only argument (sys.argv[0] is always the script name)
+        # Use absolut import in the __main__ module
-        from revpicommander import __version__
-        print(__version__)
-        sys.exit(0)
-
-    else:
         from revpicommander.revpicommander import main
 
         # Run the main application of this package
         sys.exit(main())
+
+    except Exception as e:
+        sys.stdout.write(f"Can not start __main__ module: {e}")
+        sys.stdout.write("\n")
+        sys.exit(1)

src/revpicommander/proginit.py

@@ -1,45 +1,118 @@
 # -*- coding: utf-8 -*-
 """Global program initialization."""
+# SPDX-FileCopyrightText: 2018-2023 Sven Sager
+# SPDX-License-Identifier: LGPL-2.0-or-later
 __author__ = "Sven Sager"
-__copyright__ = "Copyright (C) 2023 Sven Sager"
+__copyright__ = "Copyright (C) 2018-2023 Sven Sager"
-__license__ = "GPLv2"
+__license__ = "LGPL-2.0-or-later"
+__version__ = "1.3.0"
 
 import logging
 import sys
 from argparse import ArgumentParser
 from configparser import ConfigParser
-from os import R_OK, W_OK, access
+from os import R_OK, W_OK, access, environ, getpid, remove
-from os.path import abspath, dirname, join
+from os.path import abspath, dirname, exists, join
+from shutil import copy, move
+from socket import AF_UNIX, SOCK_DGRAM, socket
+from threading import Event
+
+try:
+    # Import program version from meta data module of your program
+    from . import __version__ as external_version
+except Exception:
+    external_version = None
 
 # Program name
 programname = "revpicommander"
+program_version = external_version
 
-# Set to True, if you want to save config file
+conf_rw = False  # If you want so save the configuration with .save_conf() set to True
-conf_rw = False
+conf_rw_save = False  # Create new conf file in same directory and move to old one
+conf_rw_backup = False  # Keep a backup of old conf file [filename].bak
+_extend_daemon_startup_timeout = 0.0  # Default startup timeout is 90 seconds
 
 conf = ConfigParser()
 logger = logging.getLogger()
 pidfile = "/var/run/{0}.pid".format(programname)
+_daemon_started_up = Event()
+_daemon_main_pid = getpid()
+_systemd_notify = environ.get("NOTIFY_SOCKET", None)
+if _systemd_notify:
+    # Set up the notification socket for systemd communication
+    _systemd_socket = socket(family=AF_UNIX, type=SOCK_DGRAM)
+    if _extend_daemon_startup_timeout:
+        # Extend systemd TimeoutStartSec by defined timeout extension in micro seconds
+        _systemd_socket.sendto(
+            f"EXTEND_TIMEOUT_USEC={_extend_daemon_startup_timeout * 1000000}\n",
+            _systemd_notify,
+        )
+
+
+def can_be_forked():
+    """
+    Check the possibility of forking the process.
+
+    Under certain circumstances, a process cannot be forked. These include
+    certain build settings or packaging, as well as the missing function on
+    some operating systems.
+
+    :return: True, if forking is possible
+    """
+    from sys import platform
+
+    # Windows operating system does not support the .fork() call
+    if platform.startswith("win"):
+        return False
+
+    # A PyInstaller bundle does not support the .fork() call
+    if getattr(sys, "frozen", False) and hasattr(sys, "_MEIPASS"):
+        return False
+
+    return True
 
 
 def cleanup():
-    """Clean up program."""
+    """
+    Clean up before exit the program.
+
+    This function must be called at the end of the program. It flushes
+    the logging buffers and deletes the PID file in daemon mode.
+    """
+    if pargs.daemon and exists(pidfile):
+        remove(pidfile)
+
     # Shutdown logging system
     logging.shutdown()
 
+    # Close logfile
+    if pargs.daemon:
+        sys.stdout.close()
+
 
 def reconfigure_logger():
     """Configure logging module of program."""
+
     # Clear all log handler
     for lhandler in logger.handlers.copy():
         lhandler.close()
         logger.removeHandler(lhandler)
 
+    if pargs.daemon:
+        # Create daemon log file
+        fh_logfile = open("/var/log/{0}.log".format(programname), "a")
+
+        # Close stdout and use logfile
+        sys.stdout.close()
+        sys.stdout = fh_logfile
+        sys.stderr = sys.stdout
+
     # Create new log handler
-    logformat = logging.Formatter(
+    if pargs.verbose > 2:
-        "{asctime} [{levelname:8}] {message}",
+        log_frm = "{asctime} [{levelname:8}] {name} {message}"
-        datefmt="%Y-%m-%d %H:%M:%S", style="{"
+    else:
-    )
+        log_frm = "{asctime} [{levelname:8}] {message}"
+    logformat = logging.Formatter(log_frm, datefmt="%Y-%m-%d %H:%M:%S", style="{")
     lhandler = logging.StreamHandler(sys.stdout)
     lhandler.setFormatter(logformat)
     logger.addHandler(lhandler)
@@ -60,53 +133,187 @@ def reconfigure_logger():
     logger.setLevel(loglevel)
 
 
-def reload_conf():
+def reload_conf(clear_load=False) -> None:
-    """Reload config file."""
+    """
-    if "conffile" in pargs:
+    Reload config file.
 
+    After successful reload, call set_startup_complete() function to inform
+    systemd that all functions are available again.
+
+    If keys are commented out in conf file, they will still be in the conf file.
+    To remove not existing keys set clear_load to True.
+
+    :param clear_load: Clear conf before reload
+    """
+    if _systemd_notify:
+        # Inform systemd about reloading configuration
+        _systemd_socket.sendto(b"RELOADING=1\n", _systemd_notify)
+
+        # Reset started up event for the set_startup_complete function
+        _daemon_started_up.clear()
+
+    if "conffile" in pargs:
         # Check config file
         if not access(pargs.conffile, R_OK):
+            raise RuntimeError("can not access config file '{0}'".format(pargs.conffile))
+        if conf_rw:
+            if (conf_rw_save or conf_rw_backup) and not access(dirname(pargs.conffile), W_OK):
                 raise RuntimeError(
-                "can not access config file '{0}'".format(pargs.conffile)
+                    "can not wirte to directory '{0}' to create files"
-            )
+                    "".format(dirname(pargs.conffile))
-        if conf_rw and not access(pargs.conffile, W_OK):
-            raise RuntimeError(
-                "can not write to config file '{0}'".format(pargs.conffile)
                 )
+            if not access(pargs.conffile, W_OK):
+                raise RuntimeError("can not write to config file '{0}'".format(pargs.conffile))
 
-        # Create global config
+        if clear_load:
-        global conf
+            # Clear all sections and do not create a new instance
+            for section in conf.sections():
+                conf.remove_section(section)
+
+        # Read configuration
         logger.info("loading config file: {0}".format(pargs.conffile))
         conf.read(pargs.conffile)
 
 
+def save_conf():
+    """Save configuration."""
+    if not conf_rw:
+        raise RuntimeError("You have to set conf_rw to True.")
+    if "conffile" in pargs:
+        if conf_rw_backup:
+            copy(pargs.conffile, pargs.conffile + ".bak")
+        if conf_rw_save:
+            with open(pargs.conffile + ".new", "w") as fh:
+                conf.write(fh)
+            move(pargs.conffile + ".new", pargs.conffile)
+        else:
+            with open(pargs.conffile, "w") as fh:
+                conf.write(fh)
+
+
+def startup_complete():
+    """
+    Call this when the daemon is completely started.
+
+    When a daemon is started, it may take some time for everything to be
+    available. This function notifies the init system when all functions of
+    this daemon are available so that the starts of further daemons can be
+    properly timed.
+
+    The systemd unit file that is supposed to start this demon must be set
+    to 'Type=notify'. If the daemon supports reloading the settings,
+    'ExecReload=/bin/kill -HUP $MAINPID' must also be set. The daemon must
+    call this function again after the reload in order to signal systemd the
+    completed reload.
+
+    If systemd is available from version 250 and the daemon supports reloading
+    the settings, 'Type=notify-reload' can be used without 'ExecReload'. The
+    type 'notify-reload' is preferable if possible, as the reloading of the
+    daemon is also synchronized with systemd.
+
+    If the '--fork' parameter is used, the main process ends after calling
+    this function to prevent the further start of demons by other init systems.
+    """
+    if _daemon_started_up.is_set():
+        # Everyone was notified about complete start, if set
+        return
+
+    if _systemd_notify:
+        # Inform systemd about complete startup of daemon process
+        _systemd_socket.sendto(b"READY=1\n", _systemd_notify)
+
+    if pargs.daemon:
+        from os import kill
+
+        # Send SIGTERM signal to main process
+        kill(_daemon_main_pid, 15)
+
+    _daemon_started_up.set()
+
+
 # Generate command arguments of the program
 parser = ArgumentParser(
     prog=programname,
-    description="Program description"
+    # todo: Add program description for help
+    description="Program description",
+)
+parser.add_argument("--version", action="version", version=f"%(prog)s {program_version}")
+parser.add_argument(
+    "-f",
+    "--logfile",
+    dest="logfile",
+    help="save log entries to this file",
 )
 parser.add_argument(
-    "-f", "--logfile", dest="logfile",
+    "-v",
-    help="Save log entries to this file"
+    "--verbose",
+    action="count",
+    dest="verbose",
+    default=0,
+    help="switch on verbose logging",
 )
-parser.add_argument(
+# If packed with opensource licenses, add argument to print license information about bundled modules
-    "-v", "--verbose", action="count", dest="verbose", default=0,
+open_source_licenses = join(dirname(__file__), "open-source-licenses", "open-source-licenses.txt")
-    help="Switch on verbose logging"
+if exists(open_source_licenses):
-)
+    parser.add_argument(
-# The __main__ script will process the version number argument
+        "--open-source-licenses",
-parser.add_argument("--version", action="store_true", help="Print version number of program and exit")
+        action="store_true",
+        dest="oss_licenses",
+        help="print packed open-source-licenses and exit",
+    )
 pargs = parser.parse_args()
 
+# Process open-source-licenses argument, if set (only affects bundled apps)
+if "oss_licenses" in pargs and pargs.oss_licenses:
+    with open(open_source_licenses, "r") as fh:
+        sys.stdout.write(fh.read())
+    sys.exit(0)
+
 # Check important objects and set to default if they do not exists
+if "daemon" not in pargs:
+    pargs.daemon = False
 if "verbose" not in pargs:
     pargs.verbose = 0
 
+# Check if the program should run as a daemon
+if pargs.daemon:
+    # Check if daemon is already running
+    if exists(pidfile):
+        logger.error("Program already running as daemon. Check '{0}'".format(pidfile))
+        sys.exit(1)
+
+    # Fork to daemon
+    from os import fork
+
+    pid = fork()
+    if pid > 0:
+        # Main process waits for exit till startup is complete
+        from os import kill
+        from signal import SIGKILL, SIGTERM, signal
+
+        # Catch the TERM signal, which will be sent from the forked process after startup_complete
+        signal(SIGTERM, lambda number, frame: _daemon_started_up.set())
+
+        # Use the default timeout of 90 seconds from systemd also for the '--daemon' flag
+        if not _daemon_started_up.wait(90.0 + _extend_daemon_startup_timeout):
+            sys.stderr.write(
+                "Run into startup complete timout! Killing fork and exit main process\n"
+            )
+            kill(pid, SIGKILL)
+            sys.exit(1)
+
+        # Main process writes pidfile with pid of forked process
+        with open(pidfile, "w") as f:
+            f.write(str(pid))
+
+        sys.exit(0)
+
+
 # Get absolute paths
 pwd = abspath(".")
 
 # Configure logger
-if "logfile" in pargs and pargs.logfile is not None \
+if "logfile" in pargs and pargs.logfile is not None and dirname(pargs.logfile) == "":
-        and dirname(pargs.logfile) == "":
     pargs.logfile = join(pwd, pargs.logfile)
 reconfigure_logger()
 

src/revpicommander/revpicommander.py

@@ -90,6 +90,8 @@ class RevPiCommander(QtWidgets.QMainWindow, Ui_win_revpicommander):
 
         self.setWindowFlag(QtCore.Qt.WindowMaximizeButtonHint, False)
 
+        pi.startup_complete()
+
     def closeEvent(self, a0: QtGui.QCloseEvent) -> None:
         log.debug("RevPiCommander.closeEvent")
         helper.cm.pyload_disconnect()