feat: add uvicorn app_factory, single worker (#44)

Adopt the app_factory + --factory pattern for serving the API. Ships a
single worker for now; multi-worker is deferred because it is unsafe with
SQLite storage and the in-memory AuthStateCache (concurrent-write
"database is locked" errors; each worker would get its own auth cache).

Author: doron1

packages/api/Dockerfile

@@ -32,4 +32,4 @@ WORKDIR /app
 USER app
 EXPOSE 8000
 
-CMD ["sh", "-c", "uvicorn api.main:app --host ${HOST} --port ${PORT} --log-level info"]
+CMD ["sh", "-c", "uvicorn api.main:app_factory --factory --host ${HOST} --port ${PORT} --log-level info"]

packages/api/dev.Dockerfile

@@ -18,4 +18,4 @@ ENV HOST=0.0.0.0 PORT=8000 DEBUG=true
 
 EXPOSE 8000
 
-CMD ["uvicorn", "api.main:app", "--host", "0.0.0.0", "--port", "8000", "--reload", "--log-level", "info"]
+CMD ["uvicorn", "api.main:app_factory", "--factory", "--host", "0.0.0.0", "--port", "8000", "--reload", "--log-level", "info"]

packages/api/run_server.py

@@ -19,9 +19,10 @@
     print(f"Health check: http://{host}:{port}/api/health")
 
     uvicorn.run(
-        "api.main:app",
+        "api.main:app_factory",
         host=host,
         port=port,
+        factory=True,
         reload=debug,
         log_level="info" if not debug else "debug",
     )

packages/api/src/api/main.py

@@ -93,3 +93,7 @@ async def lifespan(app: Litestar) -> AsyncGenerator[None, None]:
 
 
 app = create_app()
+
+
+def app_factory() -> Litestar:
+    return create_app()

packages/api/tests/unit/test_main.py

@@ -1,6 +1,8 @@
 from datetime import datetime
 
 from api.controllers.monitoring import health_check
+from api.main import app_factory
+from litestar import Litestar
 from litestar.config.cors import CORSConfig
 from litestar.testing import create_test_client
 
@@ -11,6 +13,9 @@ def test_it_creates_app_with_default_config(self, app):
         assert app is not None
         assert len(app.routes) > 0
 
+    def test_it_app_factory_returns_litestar_app(self):
+        assert isinstance(app_factory(), Litestar)
+
     def test_it_handles_cors_correctly(self):
         cors_config = CORSConfig(
             allow_origins=["*"],