support signals

with this, we are closing down the application safely, and additionally
adding support for some nice interfacing

Signed-off-by: Mazunki Hoksaas <rolferen@gmail.com>

README.md

@@ -100,7 +100,7 @@ If a configuration file is not found, a default one will be generated. If you wa
 - `frequency` (default `5`): how often (in seconds) we wait between updates
 - `cards` (required): a list of card names (from `/sys/class/drm`) which we want to control.
 
-Note! You can send a **SIGHUP** signal to the daemon to request a reload of the config without restarting the whole service.
+Note! You can send a **SIGHUP** signal to the daemon to request a reload of the config without restarting the whole service. Additionally, if you're using a pidfile, you can send a signal to reload the config with `amdfan daemon --signal=reload`
 
 # Install
 

amdfan/commands.py

@@ -2,6 +2,7 @@
 """ entry point for amdfan """
 # noqa: E501
 import os
+import signal
 import sys
 import time
 from typing import Dict
@@ -122,7 +123,18 @@ def run_daemon(
         logfile = None
 
     if action:
-        pass  # nyi
+        try:
+            with open(pidfile) as f:
+                pid = int(f.read())
+                if action == "stop":
+                    os.kill(pid, signal.SIGTERM)
+                elif action == "reload":
+                    os.kill(pid, signal.SIGHUP)
+
+        except FileNotFoundError:
+            LOGGER.warning("Could not find pidfile=%s", pidfile)
+        except ValueError:
+            LOGGER.warning("Invalid PID value in pidfile=%s", pidfile)
     else:
         FanController.start_manager(
             notification_fd=notification_fd,

amdfan/controller.py

@@ -5,6 +5,7 @@
 import re
 import signal
 import sys
+import threading
 import time
 from typing import Any, Callable, Dict, List, Optional, Self
 
@@ -238,11 +239,20 @@ class FanController:  # pylint: disable=too-few-public-methods
 
     def __init__(self, config_path, notification_fd=None) -> None:
         self.config_path = config_path
-        self.reload_config()
+        self.load_config()
         self._last_temp = 0
         self._ready_fd = notification_fd
+        self._running = False
+        self._stop_event = threading.Event()
 
     def reload_config(self, *_) -> None:
+        self.load_config()
+
+    def terminate(self, *_) -> None:
+        self._running = False
+        self._stop_event.set()
+
+    def load_config(self) -> None:
         config = load_config(self.config_path)
         self.apply(config)
 
@@ -256,15 +266,17 @@ def apply(self, config) -> None:
         self._frequency = config.get("frequency", 5)
 
     def main(self) -> None:
-        LOGGER.info("Starting amdfan")
         if self._ready_fd is not None:
             report_ready(self._ready_fd)
 
-        while True:
+        self._running = True
+        LOGGER.info("Controller is running")
+        while self._running:
             for name, card in self._scanner.cards.items():
                 self.refresh_card(name, card)
 
-            time.sleep(self._frequency)
+            self._stop_event.wait(self._frequency)
+        LOGGER.info("Stopped controller")
 
     def refresh_card(self, name, card):
         apply = True
@@ -348,9 +360,10 @@ def start_manager(
 
         controller = cls(config_path, notification_fd=notification_fd)
         signal.signal(signal.SIGHUP, controller.reload_config)
+        signal.signal(signal.SIGTERM, controller.terminate)
+        signal.signal(signal.SIGINT, controller.terminate)
         controller.main()
-
-        return controller
+        LOGGER.info("Goodbye")
 
 
 def load_config(path) -> Callable: