Be less aggressive about stopping the event loop

If we stop the event loop during aiorun's shutdown phase, we can cause
all sorts of pain (the loop may stop before all tasks have had a chance
to finish shutting down). We *should* only see `async_main` being
cancelled if aiorun is the one doing it (I hope), and if another
exception is thrown then aiorun's exception handler should see it and
stop the loop for us. Probably.

src/farmer/reporter/__init__.py

@@ -322,29 +322,27 @@ async def get_job_details(self, *, job_id: str) -> Any:
 
 
 async def async_main():
-    try:
-        reporter = FarmerReporter()
-        await reporter.start()
-        # TODO: retry logic?
-        # (there should be some built into fastapi_websocket_rpc)
-        disconnected = asyncio.Event()
-        async def on_disconnect(channel):
-            disconnected.set()
-        scheme, *rest = urllib.parse.urlparse(os.environ["FARMER_SERVER_BASE_URL"])
-        match scheme:
-            case "http":
-                scheme = "ws"
-            case "https":
-                scheme = "wss"
-        async with WebSocketRpcClient(
-                urllib.parse.urljoin(urlunparse((scheme, *rest)), "/internal/ws"),
-                FarmerReporterRpc(reporter),
-                on_disconnect=[on_disconnect],
-        ):
-            await disconnected.wait()
-        await reporter.stop()
-    finally:
-        asyncio.get_running_loop().stop()
+    reporter = FarmerReporter()
+    await reporter.start()
+    # TODO: retry logic?
+    # (there should be some built into fastapi_websocket_rpc)
+    disconnected = asyncio.Event()
+    async def on_disconnect(channel):
+        disconnected.set()
+    scheme, *rest = urllib.parse.urlparse(os.environ["FARMER_SERVER_BASE_URL"])
+    match scheme:
+        case "http":
+            scheme = "ws"
+        case "https":
+            scheme = "wss"
+    async with WebSocketRpcClient(
+            urllib.parse.urljoin(urlunparse((scheme, *rest)), "/internal/ws"),
+            FarmerReporterRpc(reporter),
+            on_disconnect=[on_disconnect],
+    ):
+        await disconnected.wait()
+    await reporter.stop()
+    asyncio.get_running_loop().stop()
 
 
 def main():

src/farmer/server/__init__.py

@@ -520,19 +520,17 @@ async def server_cleanup():
 
 
 async def async_main():
+    server = uvicorn.Server(uvicorn.Config(ws_app, host="0.0.0.0", port=int(os.environ.get("PORT", 8234)), lifespan="off"))
+    slack = AsyncSocketModeHandler(slack_bot, os.environ["SLACK_APP_TOKEN"])
+    # slack.start_async() would not properly dispose of resources on
+    # exit, so we do it by hand...
+    await slack.connect_async()
     try:
-        server = uvicorn.Server(uvicorn.Config(ws_app, host="0.0.0.0", port=int(os.environ.get("PORT", 8234)), lifespan="off"))
-        slack = AsyncSocketModeHandler(slack_bot, os.environ["SLACK_APP_TOKEN"])
-        # slack.start_async() would not properly dispose of resources on
-        # exit, so we do it by hand...
-        await slack.connect_async()
-        try:
-            await serve_uvicorn(server)
-        finally:
-            logging.debug("farmer quitting")
-            await slack.close_async()
+        await serve_uvicorn(server)
     finally:
-        asyncio.get_running_loop().stop()
+        logging.debug("farmer quitting")
+        await slack.close_async()
+    asyncio.get_running_loop().stop()
 
 
 def main():