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 17from concurrent import futures 18import logging 19 20import grpc 21 22import helloworld_pb2 23import helloworld_pb2_grpc 24 25 26class Greeter(helloworld_pb2_grpc.GreeterServicer): 27 28 def SayHello(self, request, context): 29 for key, value in context.invocation_metadata(): 30 print('Received initial metadata: key=%s value=%s' % (key, value)) 31 32 context.set_trailing_metadata(( 33 ('checksum-bin', b'I agree'), 34 ('retry', 'false'), 35 )) 36 return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name) 37 38 39def serve(): 40 server = grpc.server(futures.ThreadPoolExecutor(max_workers=10)) 41 helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server) 42 server.add_insecure_port('[::]:50051') 43 server.start() 44 server.wait_for_termination() 45 46 47if __name__ == '__main__': 48 logging.basicConfig() 49 serve() 50