1# Copyright 2018 The gRPC Authors 2# 3# Licensed under the Apache License, Version 2.0 (the "License"); 4# you may not use this file except in compliance with the License. 5# You may obtain a copy of the License at 6# 7# http://www.apache.org/licenses/LICENSE-2.0 8# 9# Unless required by applicable law or agreed to in writing, software 10# distributed under the License is distributed on an "AS IS" BASIS, 11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12# See the License for the specific language governing permissions and 13# limitations under the License. 14"""Example gRPC server that gets/sets metadata (HTTP2 headers)""" 15 16from __future__ import print_function 17 18from concurrent import futures 19import logging 20 21import grpc 22import helloworld_pb2 23import helloworld_pb2_grpc 24 25 26class Greeter(helloworld_pb2_grpc.GreeterServicer): 27 def SayHello(self, request, context): 28 for key, value in context.invocation_metadata(): 29 print("Received initial metadata: key=%s value=%s" % (key, value)) 30 31 context.set_trailing_metadata( 32 ( 33 ("checksum-bin", b"I agree"), 34 ("retry", "false"), 35 ) 36 ) 37 return helloworld_pb2.HelloReply(message="Hello, %s!" % request.name) 38 39 40def serve(): 41 server = grpc.server(futures.ThreadPoolExecutor(max_workers=10)) 42 helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server) 43 server.add_insecure_port("[::]:50051") 44 server.start() 45 server.wait_for_termination() 46 47 48if __name__ == "__main__": 49 logging.basicConfig() 50 serve() 51