bot: drastically catch exceptions

For whatever reason systemd stop signals are not caught anymore by the
"except KeyboardInterrupt", so the storage file is lost on what should
be a graceful shutdown.

edmond/bot.py

@@ -2,6 +2,7 @@ import importlib
 import json
 import os
 import time
+import signal
 from pathlib import Path
 
 import irc.client
@@ -21,6 +22,7 @@ class Bot(irc.client.SimpleIRCClient, Logger):
         self.plugins = []
         self.values = {}
         self.storage = self.__get_storage()
+        self.done = False
 
     @property
     def nick(self):
@@ -111,13 +113,15 @@ class Bot(irc.client.SimpleIRCClient, Logger):
         self.load_plugins()
         self.log_i("Connecting to server.")
         self.connect(self.config["host"], self.config["port"], self.nick)
+        signal.signal(signal.SIGTERM, self.handle_sigterm)
         try:
             self.start()
         except KeyboardInterrupt:
             self.log_i("Caught keyboard interrupt.")
+        except:  # Yes, I know, who are you going to call?
+            self.log_i("Caught unhandled exception.")
         finally:
-            self.log_i("Stopping Edmond.")
-            self.__save_storage()
+            self.cleanup()
 
     def load_plugins(self):
         """Load all installed plugins."""
@@ -171,3 +175,17 @@ class Bot(irc.client.SimpleIRCClient, Logger):
                 continue
             if callbacks[etype](event):
                 break
+
+    def handle_sigterm(self, *args):
+        """Handle SIGTERM (keyboard interrupt, systemd stop, etc)."""
+        self.cleanup()
+
+    def cleanup(self):
+        """Save the storage file and close the connection. Run only once."""
+        if self.done:
+            return
+        self.log_i("Stopping Edmond.")
+        self.__save_storage()
+        if self.connection.is_connected():
+            self.connection.close()
+        self.done = True