[ENH] Add hot reloading for development (conda-incubator#907)

conda-store-server/conda_store_server/_internal/server/app.py

@@ -207,9 +207,6 @@ def initialize(self, *args, **kwargs):
             f"Running conda-store with store directory: {self.conda_store.store_directory}"
         )
 
-        if self.conda_store.upgrade_db:
-            dbutil.upgrade(self.conda_store.database_url)
-
         self.authentication = self.authentication_class(
             parent=self,
             log=self.log,
@@ -389,7 +386,9 @@ def _check_worker(self, delay=5):
             )
 
     def start(self):
-        fastapi_app = self.init_fastapi_app()
+        """Start the CondaStoreServer application, and run a FastAPI-based webserver."""
+        if self.conda_store.upgrade_db:
+            dbutil.upgrade(self.conda_store.database_url)
 
         with self.conda_store.session_factory() as db:
             self.conda_store.ensure_settings(db)
@@ -431,6 +430,10 @@ def start(self):
             process = multiprocessing.Process(target=CondaStoreWorker.launch_instance)
             process.start()
 
+            # If running in standalone mode, also enable automatic reloading of the
+            # webserver
+            self.reload = True
+
         try:
             # Note: the logger needs to be defined here for the output to show
             # up, self.log doesn't work here either
@@ -440,7 +443,7 @@ def start(self):
             logger.info(f"Starting server on {self.address}:{self.port}")
 
             uvicorn.run(
-                fastapi_app,
+                "conda_store_server._internal.server.app:CondaStoreServer.create_webserver",
                 host=self.address,
                 port=self.port,
                 workers=1,
@@ -452,7 +455,9 @@ def start(self):
                     if self.reload
                     else []
                 ),
+                factory=True,
             )
+
         except:
             import traceback
 
@@ -462,3 +467,17 @@ def start(self):
             if self.standalone:
                 process.join()
             worker_checker.join()
+
+    @classmethod
+    def create_webserver(cls: type) -> FastAPI:
+        """Create a CondaStoreServer instance to load the config, then return a FastAPI app.
+
+        Returns
+        -------
+        FastAPI
+            A FastAPI app configured using a fresh CondaStoreServer instance
+
+        """
+        app = cls()
+        app.initialize()
+        return app.init_fastapi_app()

docusaurus-docs/community/contribute/contribute-code.md

@@ -106,7 +106,10 @@ subprocess of the web server.
     conda-store-server --standalone
     ```
 
-4. You should now be able to access the `conda-store` server at [localhost:8080](http://localhost:8080/) from your web browser.
+4. You should now be able to access the `conda-store` server at
+   [localhost:8080](http://localhost:8080/) from your web browser. Note that
+   this will enable hot reloading by default, allowing code changes to be picked
+   up by the webserver immediately without restart.
 
 ## `conda-store-ui`
 

tests/assets/conda_store_config.py

@@ -46,6 +46,7 @@
 c.CondaStoreServer.enable_ui = True
 c.CondaStoreServer.enable_api = True
 c.CondaStoreServer.enable_registry = True
+c.CondaStoreServer.reload = True
 c.CondaStoreServer.enable_metrics = True
 c.CondaStoreServer.address = "0.0.0.0"
 c.CondaStoreServer.port = 8080