[RRIO][Python] Add python grpc binding for mock API

.test-infra/mock-apis/buf.gen.yaml

@@ -37,4 +37,8 @@ plugins:
 - name: java
   out: src/main/java
 - name: grpc-java
-  out: src/main/java
+  out: src/main/java
+- plugin: buf.build/protocolbuffers/python:v24.4
+  out: src/main/python
+- plugin: buf.build/grpc/python:v1.59.1
+  out: src/main/python

.test-infra/mock-apis/src/main/python/proto/echo/v1/echo_pb2.py

@@ -0,0 +1,47 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
+
+# -*- coding: utf-8 -*-
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: proto/echo/v1/echo.proto
+"""Generated protocol buffer code."""
+from google.protobuf import descriptor as _descriptor
+from google.protobuf import descriptor_pool as _descriptor_pool
+from google.protobuf import symbol_database as _symbol_database
+from google.protobuf.internal import builder as _builder
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+
+
+DESCRIPTOR = _descriptor_pool.Default().AddSerializedFile(b'\n\x18proto/echo/v1/echo.proto\x12\rproto.echo.v1\"7\n\x0b\x45\x63hoRequest\x12\x0e\n\x02id\x18\x01 \x01(\tR\x02id\x12\x18\n\x07payload\x18\x02 \x01(\x0cR\x07payload\"8\n\x0c\x45\x63hoResponse\x12\x0e\n\x02id\x18\x01 \x01(\tR\x02id\x12\x18\n\x07payload\x18\x02 \x01(\x0cR\x07payload2P\n\x0b\x45\x63hoService\x12\x41\n\x04\x45\x63ho\x12\x1a.proto.echo.v1.EchoRequest\x1a\x1b.proto.echo.v1.EchoResponse\"\x00\x42;\n*org.apache.beam.testinfra.mockapis.echo.v1Z\rproto/echo/v1b\x06proto3')
+
+_globals = globals()
+_builder.BuildMessageAndEnumDescriptors(DESCRIPTOR, _globals)
+_builder.BuildTopDescriptorsAndMessages(DESCRIPTOR, 'proto.echo.v1.echo_pb2', _globals)
+if _descriptor._USE_C_DESCRIPTORS == False:
+  _globals['DESCRIPTOR']._options = None
+  _globals['DESCRIPTOR']._serialized_options = b'\n*org.apache.beam.testinfra.mockapis.echo.v1Z\rproto/echo/v1'
+  _globals['_ECHOREQUEST']._serialized_start=43
+  _globals['_ECHOREQUEST']._serialized_end=98
+  _globals['_ECHORESPONSE']._serialized_start=100
+  _globals['_ECHORESPONSE']._serialized_end=156
+  _globals['_ECHOSERVICE']._serialized_start=158
+  _globals['_ECHOSERVICE']._serialized_end=238
+# @@protoc_insertion_point(module_scope)

.test-infra/mock-apis/src/main/python/proto/echo/v1/echo_pb2_grpc.py

@@ -0,0 +1,87 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
+
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+"""Client and server classes corresponding to protobuf-defined services."""
+import grpc
+
+from proto.echo.v1 import echo_pb2 as proto_dot_echo_dot_v1_dot_echo__pb2
+
+
+class EchoServiceStub(object):
+    """EchoService simulates a mock API that echos a request.
+    """
+
+    def __init__(self, channel):
+        """Constructor.
+
+        Args:
+            channel: A grpc.Channel.
+        """
+        self.Echo = channel.unary_unary(
+                '/proto.echo.v1.EchoService/Echo',
+                request_serializer=proto_dot_echo_dot_v1_dot_echo__pb2.EchoRequest.SerializeToString,
+                response_deserializer=proto_dot_echo_dot_v1_dot_echo__pb2.EchoResponse.FromString,
+                )
+
+
+class EchoServiceServicer(object):
+    """EchoService simulates a mock API that echos a request.
+    """
+
+    def Echo(self, request, context):
+        """Echo an EchoRequest payload in an EchoResponse.
+        """
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+
+def add_EchoServiceServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+            'Echo': grpc.unary_unary_rpc_method_handler(
+                    servicer.Echo,
+                    request_deserializer=proto_dot_echo_dot_v1_dot_echo__pb2.EchoRequest.FromString,
+                    response_serializer=proto_dot_echo_dot_v1_dot_echo__pb2.EchoResponse.SerializeToString,
+            ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+            'proto.echo.v1.EchoService', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+ # This class is part of an EXPERIMENTAL API.
+class EchoService(object):
+    """EchoService simulates a mock API that echos a request.
+    """
+
+    @staticmethod
+    def Echo(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            insecure=False,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(request, target, '/proto.echo.v1.EchoService/Echo',
+            proto_dot_echo_dot_v1_dot_echo__pb2.EchoRequest.SerializeToString,
+            proto_dot_echo_dot_v1_dot_echo__pb2.EchoResponse.FromString,
+            options, channel_credentials,
+            insecure, call_credentials, compression, wait_for_ready, timeout, metadata)