gRPC integration (#476)

This is a port of grpcio-opentracing, and borrows from opencensus-ext-grpc. It
adds client and server interceptors that wrap each request in a span and use
the new context API to inject/extract the traceparent header to/from gRPC
metadata.

Co-authored-by: alrex <[email protected]>
Co-authored-by: Mauricio Vásquez <[email protected]>
Co-authored-by: Mario Jonke <[email protected]>
Co-authored-by: Daniel González <[email protected]>
Co-authored-by: Alex Boten <[email protected]>
Co-authored-by: Yusuke Tsutsumi <[email protected]>

Author: 7 people

.flake8

@@ -17,3 +17,4 @@ exclude =
   __pycache__
   ext/opentelemetry-ext-jaeger/src/opentelemetry/ext/jaeger/gen/
   ext/opentelemetry-ext-jaeger/build/*
+  docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/gen/

.isort.cfg

@@ -13,6 +13,6 @@ line_length=79
 ; docs: https://github.com/timothycrosley/isort#multi-line-output-modes
 multi_line_output=3
 skip=target
-skip_glob=ext/opentelemetry-ext-jaeger/src/opentelemetry/ext/jaeger/gen/*,.venv*/*,venv*/*
-known_first_party=opentelemetry
+skip_glob=**/gen/*,.venv*/*,venv*/*
+known_first_party=opentelemetry,opentelemetry_example_app
 known_third_party=psutil,pytest

docs/examples/opentelemetry-example-app/setup.py

@@ -41,6 +41,7 @@
         "opentelemetry-ext-flask",
         "flask",
         "requests",
+        "protobuf~=3.11",
     ],
     license="Apache-2.0",
     package_dir={"": "src"},

docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/__init__.py

@@ -0,0 +1,19 @@
+# Copyright The OpenTelemetry 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.
+
+import importlib
+import sys
+
+# gRPC-generated modules expect other generated modules to be on the path.
+sys.path.extend(importlib.util.find_spec(__name__).submodule_search_locations)

docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/gen/__init__.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python
+# Copyright The OpenTelemetry 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.
+
+from grpc_tools import protoc
+
+
+def main():
+    return protoc.main(
+        [
+            "-I.",
+            "--python_out=.",
+            "--grpc_python_out=.",
+            "helloworld.proto",
+            "route_guide.proto",
+        ]
+    )
+
+
+if __name__ == "__main__":
+    main()

docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/gen/codegen.py

@@ -0,0 +1,35 @@
+// Copyright The OpenTelemetry 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.
+
+// https://github.com/grpc/grpc/blob/master/examples/protos/helloworld.proto
+
+syntax = "proto3";
+
+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;
+}

docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/gen/helloworld.proto

@@ -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,))

docs/examples/opentelemetry-example-app/src/opentelemetry_example_app/grpc/gen/helloworld_pb2.py

@@ -0,0 +1,108 @@
+// Copyright The OpenTelemetry 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.
+
+// https://github.com/grpc/grpc/blob/master/examples/protos/route_guide.proto
+
+syntax = "proto3";
+
+package routeguide;
+
+// Interface exported by the server.
+service RouteGuide {
+  // A simple RPC.
+  //
+  // Obtains the feature at a given position.
+  //
+  // A feature with an empty name is returned if there's no feature at the given
+  // position.
+  rpc GetFeature(Point) returns (Feature) {}
+
+  // A server-to-client streaming RPC.
+  //
+  // Obtains the Features available within the given Rectangle.  Results are
+  // streamed rather than returned at once (e.g. in a response message with a
+  // repeated field), as the rectangle may cover a large area and contain a
+  // huge number of features.
+  rpc ListFeatures(Rectangle) returns (stream Feature) {}
+
+  // A client-to-server streaming RPC.
+  //
+  // Accepts a stream of Points on a route being traversed, returning a
+  // RouteSummary when traversal is completed.
+  rpc RecordRoute(stream Point) returns (RouteSummary) {}
+
+  // A Bidirectional streaming RPC.
+  //
+  // Accepts a stream of RouteNotes sent while a route is being traversed,
+  // while receiving other RouteNotes (e.g. from other users).
+  rpc RouteChat(stream RouteNote) returns (stream RouteNote) {}
+}
+
+// Points are represented as latitude-longitude pairs in the E7 representation
+// (degrees multiplied by 10**7 and rounded to the nearest integer).
+// Latitudes should be in the range +/- 90 degrees and longitude should be in
+// the range +/- 180 degrees (inclusive).
+message Point {
+  int32 latitude = 1;
+  int32 longitude = 2;
+}
+
+// A latitude-longitude rectangle, represented as two diagonally opposite
+// points "lo" and "hi".
+message Rectangle {
+  // One corner of the rectangle.
+  Point lo = 1;
+
+  // The other corner of the rectangle.
+  Point hi = 2;
+}
+
+// A feature names something at a given point.
+//
+// If a feature could not be named, the name is empty.
+message Feature {
+  // The name of the feature.
+  string name = 1;
+
+  // The point where the feature is detected.
+  Point location = 2;
+}
+
+// A RouteNote is a message sent while at a given point.
+message RouteNote {
+  // The location from which the message is sent.
+  Point location = 1;
+
+  // The message to be sent.
+  string message = 2;
+}
+
+// A RouteSummary is received in response to a RecordRoute rpc.
+//
+// It contains the number of individual points received, the number of
+// detected features, and the total distance covered as the cumulative sum of
+// the distance between each point.
+message RouteSummary {
+  // The number of points received.
+  int32 point_count = 1;
+
+  // The number of known features passed while traversing the route.
+  int32 feature_count = 2;
+
+  // The distance covered in metres.
+  int32 distance = 3;
+
+  // The duration of the traversal in seconds.
+  int32 elapsed_time = 4;
+}