#469 improved fastapi example and docs

We should always use workers == 1

examples/fastapi/frontend.py

@@ -1,4 +1,5 @@
 from fastapi import FastAPI
+
 from nicegui import ui
 
 

examples/fastapi/main.py

@@ -1,6 +1,5 @@
 #!/usr/bin/env python3
 import frontend
-import uvicorn
 from fastapi import FastAPI
 
 app = FastAPI()
@@ -14,4 +13,4 @@ def read_root():
 frontend.init(app)
 
 if __name__ == '__main__':
-    uvicorn.run(app, host='0.0.0.0', port=8000)
+    print('Please start the app with the "uvicorn" command as shown in the start.sh script')

examples/fastapi/start.sh

@@ -1,4 +1,23 @@
 #!/usr/bin/env bash
 
-# Start the FastAPI app
-uvicorn main:app --reload
+if [ "$#" -ne 1 ]; then
+  echo "Usage: $0 <prod|dev>"
+  exit 1
+fi
+
+# use path of this demo as working directory; enables starting this script from anywhere
+cd "$(dirname "$0")" 
+
+if [ "$1" = "prod" ]; then
+  echo "Starting Uvicorn server in production mode..."
+  # we also use a single worker in production mode so socket.io connections are always handled by the same worker
+  uvicorn main:app --workers 1 --log-level info --port 80
+elif [ "$1" = "dev" ]; then
+  echo "Starting Uvicorn server in development mode..."
+  # reload implies workers = 1
+  uvicorn main:app --reload --log-level debug --port 8080 
+else
+  echo "Invalid parameter. Use 'prod' or 'dev'."
+  exit 1
+fi
+

website/reference.py

@@ -1028,8 +1028,9 @@ def env_var_example():
 In production we also like using reverse proxies like [Traefik](https://doc.traefik.io/traefik/) or [NGINX](https://www.nginx.com/) to handle these details for us.
 See our [docker-compose.yml](https://github.com/zauberzeug/nicegui/blob/main/docker-compose.yml) as an example.
 
-You may also have a look at [our example for using a custom FastAPI app](https://github.com/zauberzeug/nicegui/tree/main/examples/fastapi).
+You may also have a look at [our demo for using a custom FastAPI app](https://github.com/zauberzeug/nicegui/tree/main/examples/fastapi).
 This will allow you to do very flexible deployments as described in the [FastAPI documentation](https://fastapi.tiangolo.com/deployment/).
+Note that there are additional steps required to allow multiple workers.
 ''')
 
         with ui.column().classes('w-full mt-8 arrow-links'):