From 7fd68349e3ac2dbf642cb1c7907901ad51b5d6c6 Mon Sep 17 00:00:00 2001
From: Lidi Zheng <lidiz@google.com>
Date: Wed, 12 Dec 2018 14:50:32 -0800
Subject: [PATCH] Add gRPC Python Example: Metadata
---
examples/python/metadata/README.md | 6 +
examples/python/metadata/helloworld_pb2.py | 134 ++++++++++++++++++
.../python/metadata/helloworld_pb2_grpc.py | 46 ++++++
examples/python/metadata/metadata_client.py | 48 +++++++
examples/python/metadata/metadata_server.py | 56 ++++++++
5 files changed, 290 insertions(+)
create mode 100644 examples/python/metadata/README.md
create mode 100644 examples/python/metadata/helloworld_pb2.py
create mode 100644 examples/python/metadata/helloworld_pb2_grpc.py
create mode 100644 examples/python/metadata/metadata_client.py
create mode 100644 examples/python/metadata/metadata_server.py
diff --git a/examples/python/metadata/README.md b/examples/python/metadata/README.md
new file mode 100644
index 0000000000..5aa75d504a
--- /dev/null
+++ b/examples/python/metadata/README.md
@@ -0,0 +1,6 @@
+An example showing how to add custom HTTP2 headers (or [metadata](https://grpc.io/grpc/python/glossary.html) in gRPC glossary)
+
+HTTP2 supports initial headers and trailing headers, which gRPC utilizes both of them ([learn more](https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md)).
+
+More complete documentation lives at [grpc.io](https://grpc.io/docs/tutorials/basic/python.html).
+For API reference please see [API](https://grpc.io/grpc/python/grpc.html).
diff --git a/examples/python/metadata/helloworld_pb2.py b/examples/python/metadata/helloworld_pb2.py
new file mode 100644
index 0000000000..e18ab9acc7
--- /dev/null
+++ b/examples/python/metadata/helloworld_pb2.py
@@ -0,0 +1,134 @@
+# 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('\n\x10helloworld.proto\x12\nhelloworld\"\x1c\n\x0cHelloRequest\x12\x0c\n\x04name\x18\x01 \x01(\t\"\x1d\n\nHelloReply\x12\x0f\n\x07message\x18\x01 \x01(\t2I\n\x07Greeter\x12>\n\x08SayHello\x12\x18.helloworld.HelloRequest\x1a\x16.helloworld.HelloReply\"\x00\x42\x36\n\x1bio.grpc.examples.helloworldB\x0fHelloWorldProtoP\x01\xa2\x02\x03HLWb\x06proto3')
+)
+
+
+
+
+_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
+_sym_db.RegisterFileDescriptor(DESCRIPTOR)
+
+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('\n\033io.grpc.examples.helloworldB\017HelloWorldProtoP\001\242\002\003HLW'))
+
+_GREETER = _descriptor.ServiceDescriptor(
+ name='Greeter',
+ full_name='helloworld.Greeter',
+ file=DESCRIPTOR,
+ index=0,
+ options=None,
+ serialized_start=93,
+ serialized_end=166,
+ methods=[
+ _descriptor.MethodDescriptor(
+ name='SayHello',
+ full_name='helloworld.Greeter.SayHello',
+ index=0,
+ containing_service=None,
+ input_type=_HELLOREQUEST,
+ output_type=_HELLOREPLY,
+ options=None,
+ ),
+])
+_sym_db.RegisterServiceDescriptor(_GREETER)
+
+DESCRIPTOR.services_by_name['Greeter'] = _GREETER
+
+# @@protoc_insertion_point(module_scope)
diff --git a/examples/python/metadata/helloworld_pb2_grpc.py b/examples/python/metadata/helloworld_pb2_grpc.py
new file mode 100644
index 0000000000..18e07d1679
--- /dev/null
+++ b/examples/python/metadata/helloworld_pb2_grpc.py
@@ -0,0 +1,46 @@
+# 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,
+ )
+
+
+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 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,
+ ),
+ }
+ generic_handler = grpc.method_handlers_generic_handler(
+ 'helloworld.Greeter', rpc_method_handlers)
+ server.add_generic_rpc_handlers((generic_handler,))
diff --git a/examples/python/metadata/metadata_client.py b/examples/python/metadata/metadata_client.py
new file mode 100644
index 0000000000..f2a8e37cc2
--- /dev/null
+++ b/examples/python/metadata/metadata_client.py
@@ -0,0 +1,48 @@
+# Copyright 2018 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Example gRPC client that gets/sets metadata (HTTP2 headers)"""
+
+from __future__ import print_function
+import logging
+
+import grpc
+
+import helloworld_pb2
+import helloworld_pb2_grpc
+
+
+def run():
+ # NOTE(gRPC Python Team): .close() is possible on a channel and should be
+ # used in circumstances in which the with statement does not fit the needs
+ # of the code.
+ with grpc.insecure_channel('localhost:50051') as channel:
+ stub = helloworld_pb2_grpc.GreeterStub(channel)
+ response, call = stub.SayHello.with_call(
+ helloworld_pb2.HelloRequest(name='you'),
+ metadata=(
+ ('initial-metadata-1', 'The value should be str'),
+ ('binary-metadata-bin',
+ b'With -bin surffix, the value can be bytes'),
+ ('accesstoken', 'gRPC Python is great'),
+ ))
+
+ print("Greeter client received: " + response.message)
+ for key, value in call.trailing_metadata():
+ print('Greeter client received trailing metadata: key=%s value=%s' %
+ (key, value))
+
+
+if __name__ == '__main__':
+ logging.basicConfig()
+ run()
diff --git a/examples/python/metadata/metadata_server.py b/examples/python/metadata/metadata_server.py
new file mode 100644
index 0000000000..a4329df79a
--- /dev/null
+++ b/examples/python/metadata/metadata_server.py
@@ -0,0 +1,56 @@
+# Copyright 2018 The gRPC Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Example gRPC server that gets/sets metadata (HTTP2 headers)"""
+
+from __future__ import print_function
+from concurrent import futures
+import time
+import logging
+
+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):
+ for key, value in context.invocation_metadata():
+ print('Received initial metadata: key=%s value=%s' % (key, value))
+
+ context.set_trailing_metadata((
+ ('checksum-bin', b'I agree'),
+ ('retry', 'false'),
+ ))
+ 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__':
+ logging.basicConfig()
+ serve()
--
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