grpc python quickstart

参考:grpc python quickstart
の準備を
1.pipのアップグレード

$ python -m pip install --upgrade pip

2.grpcのインストール

$ python -m pip install grpcio

3.grpc toolsのインストール

$ python -m pip install grpcio-tools

4.exampleのダウンロード

$ # Clone the repository to get the example code:
$ git clone https://github.com/grpc/grpc
$ # Navigate to the "hello, world" Python example:
$ cd grpc/examples/python/helloworld

簡単なCS demoを実行
Terminal A:

$ python greeter_server.py

Terminal B:

$ python greeter_client.py

greeter_server.py:

# Copyright 2015, Google Inc.
# All rights reserved.
# ...

"""The Python implementation of the GRPC helloworld.Greeter server."""

from concurrent import futures
import time

import grpc

import helloworld_pb2
import helloworld_pb2_grpc

_ONE_DAY_IN_SECONDS = 60 * 60 * 24


class Greeter(helloworld_pb2_grpc.GreeterServicer):

  def SayHello(self, request, context):
    return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)


def serve():
  server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
  helloworld_pb2_grpc.add_GreeterServicer_to_server(Greeter(), server)
  server.add_insecure_port('[::]:50051')
  server.start()
  try:
    while True:
      time.sleep(_ONE_DAY_IN_SECONDS)
  except KeyboardInterrupt:
    server.stop(0)

if __name__ == '__main__':
  serve()

greeter_client.py:

# Copyright 2015, Google Inc.
# All rights reserved.
# ... 

"""The Python implementation of the GRPC helloworld.Greeter client."""

from __future__ import print_function

import grpc

import helloworld_pb2
import helloworld_pb2_grpc


def run():
  channel = grpc.insecure_channel('localhost:50051')
  stub = helloworld_pb2_grpc.GreeterStub(channel)
  response = stub.SayHello(helloworld_pb2.HelloRequest(name='you'))
  print("Greeter client received: " + response.message)


if __name__ == '__main__':
  run()

その結果、クライアントは次のように表示されます.

root@ubuntu:/home/wasdns/grpc/examples/python/helloworld# python greeter_client.py 
Greeter client received: Hello, you!

Make a Difference
1.本例の*.protoファイル:

// Copyright 2015, Google Inc.
// All rights reserved.
// ...

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}

次のように変更します.

syntax = "proto3";

option java_multiple_files = true;
option java_package = "io.grpc.examples.helloworld";
option java_outer_classname = "HelloWorldProto";
option objc_class_prefix = "HLW";

package helloworld;

// The greeting service definition.
service Greeter {
  // Sends a greeting
  rpc SayHello (HelloRequest) returns (HelloReply) {}
  // Say Hello Again
  rpc SayHelloAgain (HelloRequest) returns (HelloReply) {}
}

// The request message containing the user's name.
message HelloRequest {
  string name = 1;
}

// The response message containing the greetings
message HelloReply {
  string message = 1;
}

2.examples/python/helloworldディレクトリで、次のことを行います.

$ python -m grpc_tools.protoc -I../../protos --python_out=. --grpc_python_out=. ../../protos/helloworld.proto

このコマンドは、要求および返信クラス定義を含むhelloworld_pb2.pyと、クライアントおよびサービス側クラス定義を含むhelloworld_pb2_grpc.pyの2つのファイルを生成します.
3.demoを更新して実行する:greeter_server.pyの内容を次のように変更します.

class Greeter(helloworld_pb2_grpc.GreeterServicer):

  def SayHello(self, request, context):
    return helloworld_pb2.HelloReply(message='Hello, %s!' % request.name)

  def SayHelloAgain(self, request, context):
    return helloworld_pb2.HelloReply(message='Hello again, %s!' % request.name)

greeter_client.pyの内容を次のように変更します.

def run():
  channel = grpc.insecure_channel('localhost:50051')
  stub = helloworld_pb2_grpc.GreeterStub(channel)
  response = stub.SayHello(helloworld_pb2.HelloRequest(name='wasdns'))
  print("Greeter client received: " + response.message)
  response = stub.SayHelloAgain(helloworld_pb2.HelloRequest(name='wasdns'))
  print("Greeter client received: " + response.message)

実行:

root@ubuntu:/home/wasdns/grpc/examples/python/helloworld# python greeter_client.py 
Greeter client received: Hello, wasdns!
Greeter client received: Hello Again, wasdns!

Appendix helloworld_pb2.py :

# Generated by the protocol buffer compiler.  DO NOT EDIT!
# source: helloworld.proto

import sys
_b=sys.version_info[0]<3 and (lambda x:x) or (lambda x:x.encode('latin1'))
from google.protobuf import descriptor as _descriptor
from google.protobuf import message as _message
from google.protobuf import reflection as _reflection
from google.protobuf import symbol_database as _symbol_database
from google.protobuf import descriptor_pb2
# @@protoc_insertion_point(imports)

_sym_db = _symbol_database.Default()




DESCRIPTOR = _descriptor.FileDescriptor(
  name='helloworld.proto',
  package='helloworld',
  syntax='proto3',
  serialized_pb=_b('
\x10helloworld.proto\x12
helloworld\"\x1c
\x0cHelloRequest\x12\x0c
\x04name\x18\x01 \x01(\t\"\x1d

HelloReply\x12\x0f
\x07message\x18\x01 \x01(\t2\x8e\x01
\x07Greeter\x12>
\x08SayHello\x12\x18.helloworld.HelloRequest\x1a\x16.helloworld.HelloReply\"\x00\x12\x43
\rSayHelloAgain\x12\x18.helloworld.HelloRequest\x1a\x16.helloworld.HelloReply\"\x00\x42\x36
\x1bio.grpc.examples.helloworldB\x0fHelloWorldProtoP\x01\xa2\x02\x03HLWb\x06proto3')
)
_sym_db.RegisterFileDescriptor(DESCRIPTOR)




_HELLOREQUEST = _descriptor.Descriptor(
  name='HelloRequest',
  full_name='helloworld.HelloRequest',
  filename=None,
  file=DESCRIPTOR,
  containing_type=None,
  fields=[
    _descriptor.FieldDescriptor(
      name='name', full_name='helloworld.HelloRequest.name', index=0,
      number=1, type=9, cpp_type=9, label=1,
      has_default_value=False, default_value=_b("").decode('utf-8'),
      message_type=None, enum_type=None, containing_type=None,
      is_extension=False, extension_scope=None,
      options=None),
  ],
  extensions=[
  ],
  nested_types=[],
  enum_types=[
  ],
  options=None,
  is_extendable=False,
  syntax='proto3',
  extension_ranges=[],
  oneofs=[
  ],
  serialized_start=32,
  serialized_end=60,
)


_HELLOREPLY = _descriptor.Descriptor(
  name='HelloReply',
  full_name='helloworld.HelloReply',
  filename=None,
  file=DESCRIPTOR,
  containing_type=None,
  fields=[
    _descriptor.FieldDescriptor(
      name='message', full_name='helloworld.HelloReply.message', index=0,
      number=1, type=9, cpp_type=9, label=1,
      has_default_value=False, default_value=_b("").decode('utf-8'),
      message_type=None, enum_type=None, containing_type=None,
      is_extension=False, extension_scope=None,
      options=None),
  ],
  extensions=[
  ],
  nested_types=[],
  enum_types=[
  ],
  options=None,
  is_extendable=False,
  syntax='proto3',
  extension_ranges=[],
  oneofs=[
  ],
  serialized_start=62,
  serialized_end=91,
)

DESCRIPTOR.message_types_by_name['HelloRequest'] = _HELLOREQUEST
DESCRIPTOR.message_types_by_name['HelloReply'] = _HELLOREPLY

HelloRequest = _reflection.GeneratedProtocolMessageType('HelloRequest', (_message.Message,), dict(
  DESCRIPTOR = _HELLOREQUEST,
  __module__ = 'helloworld_pb2'
  # @@protoc_insertion_point(class_scope:helloworld.HelloRequest)
  ))
_sym_db.RegisterMessage(HelloRequest)

HelloReply = _reflection.GeneratedProtocolMessageType('HelloReply', (_message.Message,), dict(
  DESCRIPTOR = _HELLOREPLY,
  __module__ = 'helloworld_pb2'
  # @@protoc_insertion_point(class_scope:helloworld.HelloReply)
  ))
_sym_db.RegisterMessage(HelloReply)


DESCRIPTOR.has_options = True
DESCRIPTOR._options = _descriptor._ParseOptions(descriptor_pb2.FileOptions(), _b('
\033io.grpc.examples.helloworldB\017HelloWorldProtoP\001\242\002\003HLW'))
try:
  # THESE ELEMENTS WILL BE DEPRECATED.
  # Please use the generated *_pb2_grpc.py files instead.
  import grpc
  from grpc.beta import implementations as beta_implementations
  from grpc.beta import interfaces as beta_interfaces
  from grpc.framework.common import cardinality
  from grpc.framework.interfaces.face import utilities as face_utilities


  class GreeterStub(object):
    """The greeting service definition.
    """

    def __init__(self, channel):
      """Constructor.

      Args:
        channel: A grpc.Channel.
      """
      self.SayHello = channel.unary_unary(
          '/helloworld.Greeter/SayHello',
          request_serializer=HelloRequest.SerializeToString,
          response_deserializer=HelloReply.FromString,
          )
      self.SayHelloAgain = channel.unary_unary(
          '/helloworld.Greeter/SayHelloAgain',
          request_serializer=HelloRequest.SerializeToString,
          response_deserializer=HelloReply.FromString,
          )


  class GreeterServicer(object):
    """The greeting service definition.
    """

    def SayHello(self, request, context):
      """Sends a greeting
      """
      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
      context.set_details('Method not implemented!')
      raise NotImplementedError('Method not implemented!')

    def SayHelloAgain(self, request, context):
      """Say Hello Again
      """
      context.set_code(grpc.StatusCode.UNIMPLEMENTED)
      context.set_details('Method not implemented!')
      raise NotImplementedError('Method not implemented!')


  def add_GreeterServicer_to_server(servicer, server):
    rpc_method_handlers = {
        'SayHello': grpc.unary_unary_rpc_method_handler(
            servicer.SayHello,
            request_deserializer=HelloRequest.FromString,
            response_serializer=HelloReply.SerializeToString,
        ),
        'SayHelloAgain': grpc.unary_unary_rpc_method_handler(
            servicer.SayHelloAgain,
            request_deserializer=HelloRequest.FromString,
            response_serializer=HelloReply.SerializeToString,
        ),
    }
    generic_handler = grpc.method_handlers_generic_handler(
        'helloworld.Greeter', rpc_method_handlers)
    server.add_generic_rpc_handlers((generic_handler,))


  class BetaGreeterServicer(object):
    """The Beta API is deprecated for 0.15.0 and later.

    It is recommended to use the GA API (classes and functions in this
    file not marked beta) for all further purposes. This class was generated
    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
    """The greeting service definition.
    """
    def SayHello(self, request, context):
      """Sends a greeting
      """
      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)
    def SayHelloAgain(self, request, context):
      """Say Hello Again
      """
      context.code(beta_interfaces.StatusCode.UNIMPLEMENTED)


  class BetaGreeterStub(object):
    """The Beta API is deprecated for 0.15.0 and later.

    It is recommended to use the GA API (classes and functions in this
    file not marked beta) for all further purposes. This class was generated
    only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0."""
    """The greeting service definition.
    """
    def SayHello(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
      """Sends a greeting
      """
      raise NotImplementedError()
    SayHello.future = None
    def SayHelloAgain(self, request, timeout, metadata=None, with_call=False, protocol_options=None):
      """Say Hello Again
      """
      raise NotImplementedError()
    SayHelloAgain.future = None


  def beta_create_Greeter_server(servicer, pool=None, pool_size=None, default_timeout=None, maximum_timeout=None):
    """The Beta API is deprecated for 0.15.0 and later.

    It is recommended to use the GA API (classes and functions in this
    file not marked beta) for all further purposes. This function was
    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
    request_deserializers = {
      ('helloworld.Greeter', 'SayHello'): HelloRequest.FromString,
      ('helloworld.Greeter', 'SayHelloAgain'): HelloRequest.FromString,
    }
    response_serializers = {
      ('helloworld.Greeter', 'SayHello'): HelloReply.SerializeToString,
      ('helloworld.Greeter', 'SayHelloAgain'): HelloReply.SerializeToString,
    }
    method_implementations = {
      ('helloworld.Greeter', 'SayHello'): face_utilities.unary_unary_inline(servicer.SayHello),
      ('helloworld.Greeter', 'SayHelloAgain'): face_utilities.unary_unary_inline(servicer.SayHelloAgain),
    }
    server_options = beta_implementations.server_options(request_deserializers=request_deserializers, response_serializers=response_serializers, thread_pool=pool, thread_pool_size=pool_size, default_timeout=default_timeout, maximum_timeout=maximum_timeout)
    return beta_implementations.server(method_implementations, options=server_options)


  def beta_create_Greeter_stub(channel, host=None, metadata_transformer=None, pool=None, pool_size=None):
    """The Beta API is deprecated for 0.15.0 and later.

    It is recommended to use the GA API (classes and functions in this
    file not marked beta) for all further purposes. This function was
    generated only to ease transition from grpcio<0.15.0 to grpcio>=0.15.0"""
    request_serializers = {
      ('helloworld.Greeter', 'SayHello'): HelloRequest.SerializeToString,
      ('helloworld.Greeter', 'SayHelloAgain'): HelloRequest.SerializeToString,
    }
    response_deserializers = {
      ('helloworld.Greeter', 'SayHello'): HelloReply.FromString,
      ('helloworld.Greeter', 'SayHelloAgain'): HelloReply.FromString,
    }
    cardinalities = {
      'SayHello': cardinality.Cardinality.UNARY_UNARY,
      'SayHelloAgain': cardinality.Cardinality.UNARY_UNARY,
    }
    stub_options = beta_implementations.stub_options(host=host, metadata_transformer=metadata_transformer, request_serializers=request_serializers, response_deserializers=response_deserializers, thread_pool=pool, thread_pool_size=pool_size)
    return beta_implementations.dynamic_stub(channel, 'helloworld.Greeter', cardinalities, options=stub_options)
except ImportError:
  pass
# @@protoc_insertion_point(module_scope)

helloworld_pb2_grpc.py :

# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
import grpc

import helloworld_pb2 as helloworld__pb2


class GreeterStub(object):
  """The greeting service definition.
  """

  def __init__(self, channel):
    """Constructor.

    Args:
      channel: A grpc.Channel.
    """
    self.SayHello = channel.unary_unary(
        '/helloworld.Greeter/SayHello',
        request_serializer=helloworld__pb2.HelloRequest.SerializeToString,
        response_deserializer=helloworld__pb2.HelloReply.FromString,
        )
    self.SayHelloAgain = channel.unary_unary(
        '/helloworld.Greeter/SayHelloAgain',
        request_serializer=helloworld__pb2.HelloRequest.SerializeToString,
        response_deserializer=helloworld__pb2.HelloReply.FromString,
        )


class GreeterServicer(object):
  """The greeting service definition.
  """

  def SayHello(self, request, context):
    """Sends a greeting
    """
    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
    context.set_details('Method not implemented!')
    raise NotImplementedError('Method not implemented!')

  def SayHelloAgain(self, request, context):
    """Say Hello Again
    """
    context.set_code(grpc.StatusCode.UNIMPLEMENTED)
    context.set_details('Method not implemented!')
    raise NotImplementedError('Method not implemented!')


def add_GreeterServicer_to_server(servicer, server):
  rpc_method_handlers = {
      'SayHello': grpc.unary_unary_rpc_method_handler(
          servicer.SayHello,
          request_deserializer=helloworld__pb2.HelloRequest.FromString,
          response_serializer=helloworld__pb2.HelloReply.SerializeToString,
      ),
      'SayHelloAgain': grpc.unary_unary_rpc_method_handler(
          servicer.SayHelloAgain,
          request_deserializer=helloworld__pb2.HelloRequest.FromString,
          response_serializer=helloworld__pb2.HelloReply.SerializeToString,
      ),
  }
  generic_handler = grpc.method_handlers_generic_handler(
      'helloworld.Greeter', rpc_method_handlers)
  server.add_generic_rpc_handlers((generic_handler,))

2017.6.5