Add requirements.txt

examples/python/xds/README.md

@@ -22,7 +22,7 @@ cd grpc/examples/python/xds
 ```sh
 virtualenv venv -p python3
 source venv/bin/activate
-pip install grpcio protobuf grpcio-reflection grpcio-health-checking
+pip install -r requirements.txt
 python server.py
 ```
 

examples/python/xds/requirements.txt

@@ -0,0 +1,5 @@
+grpcio>=1.28.0
+protobuf
+grpcio-reflection
+grpcio-health-checking
+

examples/python/xds/server.py

@@ -43,7 +43,7 @@ class Greeter(helloworld_pb2_grpc.GreeterServicer):
             message=f"Hello {request.name} from {self._hostname}!")
 
 
-def serve(port, hostname):
+def serve(port: int, hostname: str):
     server = grpc.server(
         futures.ThreadPoolExecutor(max_workers=multiprocessing.cpu_count()))