Merge pull request piccolo-orm#81 from piccolo-orm/asgi_improvements

in the ASGI template, catch connection errors

Author: dantownsend

piccolo/apps/asgi/commands/templates/starlette/_fastapi_app.py.jinja

@@ -76,11 +76,17 @@ async def delete_task(task_id: int):
 
 @app.on_event("startup")
 async def open_database_connection_pool():
-    engine = engine_finder()
-    await engine.start_connection_pool()
+    try:
+        engine = engine_finder()
+        await engine.start_connection_pool()
+    except Exception:
+        print("Unable to connect to the database")
 
 
 @app.on_event("shutdown")
 async def close_database_connection_pool():
-    engine = engine_finder()
-    await engine.close_connection_pool()
+    try:
+        engine = engine_finder()
+        await engine.close_connection_pool()
+    except Exception:
+        print("Unable to connect to the database")

piccolo/apps/asgi/commands/templates/starlette/_starlette_app.py.jinja

@@ -29,11 +29,17 @@ app = Starlette(
 
 @app.on_event("startup")
 async def open_database_connection_pool():
-    engine = engine_finder()
-    await engine.start_connection_pool()
+    try:
+        engine = engine_finder()
+        await engine.start_connection_pool()
+    except Exception:
+        print("Unable to connect to the database")
 
 
 @app.on_event("shutdown")
 async def close_database_connection_pool():
-    engine = engine_finder()
-    await engine.close_connection_pool()
+    try:
+        engine = engine_finder()
+        await engine.close_connection_pool()
+    except Exception:
+        print("Unable to connect to the database")