Some Instructions

Makefile

@@ -62,6 +62,14 @@ push: build-prod
 	@echo "\n${BLUE}Pushing image to GitHub Docker Registry...${NC}\n"
 	@docker push $(IMAGE):$(VERSION)
 
+grpc-gen:
+	@python -m grpc_tools.protoc \
+			-I $(MODULE)/proto \
+			--python_out=./$(MODULE)/generated \
+			--grpc_python_out=./$(MODULE)/generated \
+			./$(MODULE)/proto/*.proto
+	@sed -i -E 's/^import.*_pb2/from . \0/' ./$(MODULE)/generated/*.py
+
 cluster:
 	@if [ $$(kind get clusters | wc -l) = 0 ]; then \
 		kind create cluster --config ./k8s/cluster/kind-config.yaml --name kind; \

README.md

@@ -51,6 +51,14 @@ docker.pkg.github.com/martinheinz/python-project-blueprint/blueprint   0.0.5
 Hello World...
 ```
 
+## gRPC
+
+To generate gRPC sources from `.proto` files stored in `./blueprint/generated/` directory:
+
+```console
+~ $ make grpc-gen
+```
+
 ## Testing
 
 Test are ran every time you build _dev_ or _prod_ image. You can also run tests using:

blueprint/__init__.py

@@ -1 +1,3 @@
-from .app import Blueprint  # noqa: F401
+from .app import Server  # noqa: F401
+from .grpc import Echoer  # noqa: F401
+from .generated import echo_pb2  # noqa: F401

blueprint/__main__.py

@@ -1,4 +1,4 @@
-from .app import Blueprint
+from .app import Server
 
 if __name__ == '__main__':
-    Blueprint.run()
+    Server.run()

blueprint/app.py

@@ -1,5 +1,16 @@
-class Blueprint:
+from concurrent import futures
+import grpc
+
+from .generated import echo_pb2_grpc
+from .grpc import Echoer
+
+
+class Server:
 
     @staticmethod
     def run():
-        print("Hello World...")
+        server = grpc.server(futures.ThreadPoolExecutor(max_workers=10))
+        echo_pb2_grpc.add_EchoServicer_to_server(Echoer(), server)
+        server.add_insecure_port('[::]:50051')
+        server.start()
+        server.wait_for_termination()

blueprint/generated/echo_pb2_grpc.py

@@ -0,0 +1,68 @@
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+import grpc
+
+from . import echo_pb2 as echo__pb2
+
+
+class EchoStub(object):
+    """The echo service definition.
+    """
+
+    def __init__(self, channel):
+        """Constructor.
+
+        Args:
+            channel: A grpc.Channel.
+        """
+        self.Reply = channel.unary_unary(
+                '/echo.Echo/Reply',
+                request_serializer=echo__pb2.EchoRequest.SerializeToString,
+                response_deserializer=echo__pb2.EchoReply.FromString,
+                )
+
+
+class EchoServicer(object):
+    """The echo service definition.
+    """
+
+    def Reply(self, request, context):
+        """Echo back reply.
+        """
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details('Method not implemented!')
+        raise NotImplementedError('Method not implemented!')
+
+
+def add_EchoServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+            'Reply': grpc.unary_unary_rpc_method_handler(
+                    servicer.Reply,
+                    request_deserializer=echo__pb2.EchoRequest.FromString,
+                    response_serializer=echo__pb2.EchoReply.SerializeToString,
+            ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+            'echo.Echo', rpc_method_handlers)
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+ # This class is part of an EXPERIMENTAL API.
+class Echo(object):
+    """The echo service definition.
+    """
+
+    @staticmethod
+    def Reply(request,
+            target,
+            options=(),
+            channel_credentials=None,
+            call_credentials=None,
+            compression=None,
+            wait_for_ready=None,
+            timeout=None,
+            metadata=None):
+        return grpc.experimental.unary_unary(request, target, '/echo.Echo/Reply',
+            echo__pb2.EchoRequest.SerializeToString,
+            echo__pb2.EchoReply.FromString,
+            options, channel_credentials,
+            call_credentials, compression, wait_for_ready, timeout, metadata)

blueprint/grpc.py

@@ -0,0 +1,7 @@
+from .generated import echo_pb2_grpc, echo_pb2
+
+
+class Echoer(echo_pb2_grpc.EchoServicer):
+
+    def Reply(self, request, context):
+        return echo_pb2.EchoReply(message=f'You said: {request.message}')

blueprint/proto/echo.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+
+package echo;
+
+// The echo service definition.
+service Echo {
+  // Echo back reply.
+  rpc Reply (EchoRequest) returns (EchoReply) {}
+}
+
+// The request message containing the user's message.
+message EchoRequest {
+  string message = 1;
+}
+
+// The response message containing the original message.
+message EchoReply {
+  string message = 1;
+}

requirements.txt

@@ -1,3 +1,6 @@
 pytest==5.3.2
 pytest-cov==2.8.1
-Flask==1.1.1
+Flask==1.1.1
+grpcio==1.28.1
+grpcio-tools==1.28.1
+pytest-grpc==0.7.0

tests/conftest.py

@@ -1,11 +1,22 @@
-import logging
 import pytest
 
-LOGGER = logging.getLogger(__name__)
 
+@pytest.fixture(scope='module')
+def grpc_add_to_server():
+    from blueprint.generated.echo_pb2_grpc import add_EchoServicer_to_server
 
-@pytest.fixture(scope='function')
-def example_fixture():
-    LOGGER.info("Setting Up Example Fixture...")
-    yield
-    LOGGER.info("Tearing Down Example Fixture...")
+    return add_EchoServicer_to_server
+
+
+@pytest.fixture(scope='module')
+def grpc_servicer():
+    from blueprint.grpc import Echoer
+
+    return Echoer()
+
+
+@pytest.fixture(scope='module')
+def grpc_stub(grpc_channel):
+    from blueprint.generated.echo_pb2_grpc import EchoStub
+
+    return EchoStub(grpc_channel)

tests/test_grpc.py

@@ -0,0 +1,9 @@
+from .context import blueprint
+
+
+def test_reply(grpc_stub):
+    value = 'test-data'
+    request = blueprint.echo_pb2.EchoRequest(message=value)
+    response = grpc_stub.Reply(request)
+
+    assert response.message == f'You said: {value}'