Add graceful exits

This sets up a set of ropes and pulleys that signal the `Bot.keepalive`
function to clean things up after a quit signal has been sent. This
allows plugins to define an `on_unload` function to save any important
datas on intentional exit.

Signed-off-by: Alek Ratzloff <alekratz@gmail.com>

omnibot/__main__.py

@@ -1,5 +1,7 @@
 import asyncio
+from functools import partial
 import logging
+import signal
 
 from .config import ServerConfig
 from .bot import Bot
@@ -10,15 +12,18 @@ logging.basicConfig(
 )
 log = logging.getLogger(__name__)
 
+log.debug("Loading config")
+config = ServerConfig()
+config.load("config.toml")
+log.debug("Using configuration: %s", config)
 
-async def main():
-    log.debug("Loading config")
-    config = ServerConfig()
-    config.load("config.toml")
-    log.debug("Using configuration: %s", config)
+bot = Bot(config)
 
-    server = Bot(config)
-    await server.run()
-
-
-asyncio.run(main())
+try:
+    asyncio.run(bot.run())
+except KeyboardInterrupt:
+    log.info("Got ctrl-c")
+finally:
+    log.info("Quitting, press ctrl-c to quit immediately")
+    bot.quit()
+    asyncio.run(bot.keepalive())