uvicorn: add support for restarting uvicorn

Also add gstate property to request uvicorn restart.

Signed-off-by: Joshua Hesketh <jhesketh@suse.com>

src/aquarium.py

@@ -152,8 +152,6 @@ def __init__(self):
         self.static_dir = os.path.join(
             os.path.dirname(os.path.realpath(__file__)), "glass/dist/"
         )
-        # TODO(jhesketh): Move KV store set up here so we can use it
-        #                 to watch for certs.
 
     async def bootstrap(self):
         logger.info("Aquarium startup!")
@@ -230,11 +228,13 @@ async def shutdown(self):
 
     async def main_loop(self):
         while not self._is_shutting_down:
+            if self.gstate.requesting_uvicorn_restart:
+                await self.restart_uvicorn()
+                self.gstate.reset_uvicorn_restart()
             await asyncio.sleep(1)
-            # TODO(jhesketh): Watch KV store and restart uvicorn if updates to
-            #                 certs.
 
     async def start_uvicorn(self):
+        logger.debug("Starting uvicorn")
         # TODO(jhesketh): Check if we need https or not
         uvicorn_config = Config(self.app, host="0.0.0.0", port=80)
         self.uvicorn = AquariumUvicorn(config=uvicorn_config)
@@ -243,11 +243,13 @@ async def start_uvicorn(self):
         #                 instance will work to create http redirect.
 
     async def stop_uvicorn(self):
+        logger.debug("Stopping uvicorn")
         self.uvicorn.should_exit = True
         while self.uvicorn._running:
             await asyncio.sleep(0.1)
 
     async def restart_uvicorn(self):
+        logger.debug("Restarting uvicorn")
         await self.stop_uvicorn()
         await self.start_uvicorn()
 

src/gravel/controllers/gstate.py

@@ -126,6 +126,7 @@ class GlobalState:
 
     _config: Config
     _is_shutting_down: bool
+    _requesting_uvicorn_restart: bool
     _tickers: Dict[str, Ticker]
     _kvstore: KV
     devices: Devices
@@ -140,6 +141,7 @@ class GlobalState:
     def __init__(self, kv_class: Type[KV] = KV):
         self._config = Config()
         self._is_shutting_down = False
+        self._requesting_uvicorn_restart = False
         self._tickers = {}
         self._kvstore = kv_class()
 
@@ -213,10 +215,20 @@ def rm_ticker(self, desc: str) -> None:
     def get_ticker(self, desc: str) -> Ticker:
         return self._tickers[desc]
 
+    def request_restart_uvicorn(self) -> None:
+        self._requesting_uvicorn_restart = True
+
+    def reset_uvicorn_restart(self) -> None:
+        self._requesting_uvicorn_restart = False
+
     @property
     def config(self) -> Config:
         return self._config
 
     @property
     def store(self) -> KV:
         return self._kvstore
+
+    @property
+    def requesting_uvicorn_restart(self) -> bool:
+        return self._requesting_uvicorn_restart