Merge pull request #149 from d5h/microservices-with-grpc

Add materials for https://github.com/realpython/tutorial-drafts/pull/602

python-microservices-with-grpc/README.md

+# Running the Example
+
+1. Install Docker if you haven't already.
+2. Run `./build_and_run.sh`.

python-microservices-with-grpc/build_and_run.sh

+#!/bin/bash
+
+./gen_certs.sh
+
+DOCKER_BUILDKIT=1 docker build . -f marketplace/Dockerfile -t marketplace --secret id=ca.key,src=ca.key
+DOCKER_BUILDKIT=1 docker build . -f recommendations/Dockerfile -t recommendations --secret id=ca.key,src=ca.key
+
+docker-compose up

python-microservices-with-grpc/docker-compose.yaml

+version: "3.8"
+services:
+
+    marketplace:
+        environment:
+            RECOMMENDATIONS_HOST: recommendations
+        # DOCKER_BUILDKIT=1 docker build . -f marketplace/Dockerfile \
+        #                   -t marketplace --secret id=ca.key,src=ca.key
+        image: marketplace
+        networks:
+            - microservices
+        ports:
+            - 5000:5000
+
+    recommendations:
+        # DOCKER_BUILDKIT=1 docker build . -f recommendations/Dockerfile \
+        #                   -t recommendations --secret id=ca.key,src=ca.key
+        image: recommendations
+        networks:
+            - microservices
+
+networks:
+    microservices:

python-microservices-with-grpc/gen_certs.sh

+#!/bin/bash
+
+# Generate CA key and self-signed cert
+openssl req -x509 -nodes -newkey rsa:4096 -keyout ca.key -out ca.pem -subj /O=me
+
+# Generate a private key and certificate signing request for the client and server
+openssl req -nodes -newkey rsa:4096 -keyout client.key -out client.csr -subj /CN=marketplace
+openssl req -nodes -newkey rsa:4096 -keyout server.key -out server.csr -subj /CN=recommendations
+
+# Sign the client and server certs with the CA cert
+openssl x509 -req -in client.csr -CA ca.pem -CAkey ca.key -set_serial 1 -out client.pem
+openssl x509 -req -in server.csr -CA ca.pem -CAkey ca.key -set_serial 1 -out server.pem

python-microservices-with-grpc/integration_tests.sh

+#!/bin/bash
+
+set -euo pipefail
+
+docker-compose up -d
+trap "docker-compose down" EXIT
+
+sleep 5  # Give the services time to warm up
+docker-compose exec marketplace pytest

python-microservices-with-grpc/kubernetes.yaml

+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+    name: marketplace
+    labels:
+        app: marketplace
+spec:
+    replicas: 1
+    selector:
+        matchLabels:
+            app: marketplace
+    template:
+        metadata:
+            labels:
+                app: marketplace
+        spec:
+            containers:
+                - name: marketplace
+                  image: hidan/python-microservices-article-marketplace:0.1
+                  env:
+                      - name: RECOMMENDATIONS_HOST
+                        value: recommendations
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+    name: recommendations
+    labels:
+        app: recommendations
+spec:
+    replicas: 1
+    selector:
+        matchLabels:
+            app: recommendations
+    template:
+        metadata:
+            labels:
+                app: recommendations
+        spec:
+            containers:
+                - name: recommendations
+                  image: hidan/python-microservices-article-recommendations:0.1
+---
+apiVersion: v1
+kind: Service
+metadata:
+    name: recommendations
+spec:
+    selector:
+        app: recommendations
+    ports:
+        - protocol: TCP
+          port: 50051
+          targetPort: 50051
+---
+apiVersion: v1
+kind: Service
+metadata:
+    name: marketplace
+spec:
+    type: LoadBalancer
+    selector:
+        app: marketplace
+    ports:
+        - protocol: TCP
+          port: 5000
+          targetPort: 5000

python-microservices-with-grpc/marketplace/Dockerfile

+# syntax = docker/dockerfile:1.0-experimental
+# DOCKER_BUILDKIT=1 docker build . -f marketplace/Dockerfile -t marketplace --secret id=ca.key,src=ca.key
+
+FROM python
+
+RUN mkdir /service
+COPY protobufs/ /service/protobufs/
+COPY marketplace/ /service/marketplace/
+COPY ca.pem /service/marketplace/
+
+WORKDIR /service/marketplace
+RUN pip install -r requirements.txt
+RUN python -m grpc_tools.protoc -I ../protobufs --python_out=. \
+           --grpc_python_out=. ../protobufs/recommendations.proto
+RUN openssl req -nodes -newkey rsa:4096 -subj /CN=marketplace \
+                -keyout client.key -out client.csr
+RUN --mount=type=secret,id=ca.key \
+    openssl x509 -req -in client.csr -CA ca.pem -CAkey /run/secrets/ca.key \
+                 -set_serial 1 -out client.pem
+
+EXPOSE 5000
+ENV FLASK_APP=marketplace.py
+ENTRYPOINT [ "flask", "run", "--host=0.0.0.0"]

python-microservices-with-grpc/marketplace/marketplace.py

+import os
+
+from flask import Flask, render_template
+import grpc
+
+from recommendations_pb2 import BookCategory, RecommendationRequest
+from recommendations_pb2_grpc import RecommendationsStub
+
+app = Flask(__name__)
+
+recommendations_host = os.getenv("RECOMMENDATIONS_HOST", "localhost")
+with open("client.key", "rb") as fp:
+    client_key = fp.read()
+with open("client.pem", "rb") as fp:
+    client_cert = fp.read()
+with open("ca.pem", "rb") as fp:
+    ca_cert = fp.read()
+creds = grpc.ssl_channel_credentials(ca_cert, client_key, client_cert)
+recommendations_channel = grpc.secure_channel(
+    f"{recommendations_host}:443", creds
+)
+recommendations_client = RecommendationsStub(recommendations_channel)
+
+
+@app.route("/")
+def render_homepage():
+    recommendations_request = RecommendationRequest(
+        user_id=1, category=BookCategory.MYSTERY, max_results=3
+    )
+    recommendations_response = recommendations_client.Recommend(
+        recommendations_request
+    )
+    return render_template(
+        "homepage.html",
+        recommendations=recommendations_response.recommendations,
+    )

python-microservices-with-grpc/marketplace/marketplace_integration_test.py

+from urllib.request import urlopen
+
+
+def test_render_homepage():
+    homepage_html = urlopen("http://localhost:5000").read().decode("utf-8")
+    assert "<title>Online Books For You</title>" in homepage_html
+    assert homepage_html.count("<li>") == 3

python-microservices-with-grpc/marketplace/recommendations_pb2.py

+# -*- coding: utf-8 -*-
+# flake8: noqa
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: recommendations.proto
+
+from google.protobuf.internal import enum_type_wrapper
+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
+
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+DESCRIPTOR = _descriptor.FileDescriptor(
+    name="recommendations.proto",
+    package="",
+    syntax="proto3",
+    serialized_options=None,
+    serialized_pb=b'\n\x15recommendations.proto"^\n\x15RecommendationRequest\x12\x0f\n\x07user_id\x18\x01 \x01(\x05\x12\x1f\n\x08\x63\x61tegory\x18\x02 \x01(\x0e\x32\r.BookCategory\x12\x13\n\x0bmax_results\x18\x03 \x01(\x05"/\n\x12\x42ookRecommendation\x12\n\n\x02id\x18\x01 \x01(\x05\x12\r\n\x05title\x18\x02 \x01(\t"F\n\x16RecommendationResponse\x12,\n\x0frecommendations\x18\x01 \x03(\x0b\x32\x13.BookRecommendation*?\n\x0c\x42ookCategory\x12\x0b\n\x07MYSTERY\x10\x00\x12\x13\n\x0fSCIENCE_FICTION\x10\x01\x12\r\n\tSELF_HELP\x10\x02\x32O\n\x0fRecommendations\x12<\n\tRecommend\x12\x16.RecommendationRequest\x1a\x17.RecommendationResponseb\x06proto3',
+)
+
+_BOOKCATEGORY = _descriptor.EnumDescriptor(
+    name="BookCategory",
+    full_name="BookCategory",
+    filename=None,
+    file=DESCRIPTOR,
+    values=[
+        _descriptor.EnumValueDescriptor(
+            name="MYSTERY",
+            index=0,
+            number=0,
+            serialized_options=None,
+            type=None,
+        ),
+        _descriptor.EnumValueDescriptor(
+            name="SCIENCE_FICTION",
+            index=1,
+            number=1,
+            serialized_options=None,
+            type=None,
+        ),
+        _descriptor.EnumValueDescriptor(
+            name="SELF_HELP",
+            index=2,
+            number=2,
+            serialized_options=None,
+            type=None,
+        ),
+    ],
+    containing_type=None,
+    serialized_options=None,
+    serialized_start=242,
+    serialized_end=305,
+)
+_sym_db.RegisterEnumDescriptor(_BOOKCATEGORY)
+
+BookCategory = enum_type_wrapper.EnumTypeWrapper(_BOOKCATEGORY)
+MYSTERY = 0
+SCIENCE_FICTION = 1
+SELF_HELP = 2
+
+
+_RECOMMENDATIONREQUEST = _descriptor.Descriptor(
+    name="RecommendationRequest",
+    full_name="RecommendationRequest",
+    filename=None,
+    file=DESCRIPTOR,
+    containing_type=None,
+    fields=[
+        _descriptor.FieldDescriptor(
+            name="user_id",
+            full_name="RecommendationRequest.user_id",
+            index=0,
+            number=1,
+            type=5,
+            cpp_type=1,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+        _descriptor.FieldDescriptor(
+            name="category",
+            full_name="RecommendationRequest.category",
+            index=1,
+            number=2,
+            type=14,
+            cpp_type=8,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+        _descriptor.FieldDescriptor(
+            name="max_results",
+            full_name="RecommendationRequest.max_results",
+            index=2,
+            number=3,
+            type=5,
+            cpp_type=1,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+    ],
+    extensions=[],
+    nested_types=[],
+    enum_types=[],
+    serialized_options=None,
+    is_extendable=False,
+    syntax="proto3",
+    extension_ranges=[],
+    oneofs=[],
+    serialized_start=25,
+    serialized_end=119,
+)
+
+
+_BOOKRECOMMENDATION = _descriptor.Descriptor(
+    name="BookRecommendation",
+    full_name="BookRecommendation",
+    filename=None,
+    file=DESCRIPTOR,
+    containing_type=None,
+    fields=[
+        _descriptor.FieldDescriptor(
+            name="id",
+            full_name="BookRecommendation.id",
+            index=0,
+            number=1,
+            type=5,
+            cpp_type=1,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+        _descriptor.FieldDescriptor(
+            name="title",
+            full_name="BookRecommendation.title",
+            index=1,
+            number=2,
+            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,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+    ],
+    extensions=[],
+    nested_types=[],
+    enum_types=[],
+    serialized_options=None,
+    is_extendable=False,
+    syntax="proto3",
+    extension_ranges=[],
+    oneofs=[],
+    serialized_start=121,
+    serialized_end=168,
+)
+
+
+_RECOMMENDATIONRESPONSE = _descriptor.Descriptor(
+    name="RecommendationResponse",
+    full_name="RecommendationResponse",
+    filename=None,
+    file=DESCRIPTOR,
+    containing_type=None,
+    fields=[
+        _descriptor.FieldDescriptor(
+            name="recommendations",
+            full_name="RecommendationResponse.recommendations",
+            index=0,
+            number=1,
+            type=11,
+            cpp_type=10,
+            label=3,
+            has_default_value=False,
+            default_value=[],
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+    ],
+    extensions=[],
+    nested_types=[],
+    enum_types=[],
+    serialized_options=None,
+    is_extendable=False,
+    syntax="proto3",
+    extension_ranges=[],
+    oneofs=[],
+    serialized_start=170,
+    serialized_end=240,
+)
+
+_RECOMMENDATIONREQUEST.fields_by_name["category"].enum_type = _BOOKCATEGORY
+_RECOMMENDATIONRESPONSE.fields_by_name[
+    "recommendations"
+].message_type = _BOOKRECOMMENDATION
+DESCRIPTOR.message_types_by_name[
+    "RecommendationRequest"
+] = _RECOMMENDATIONREQUEST
+DESCRIPTOR.message_types_by_name["BookRecommendation"] = _BOOKRECOMMENDATION
+DESCRIPTOR.message_types_by_name[
+    "RecommendationResponse"
+] = _RECOMMENDATIONRESPONSE
+DESCRIPTOR.enum_types_by_name["BookCategory"] = _BOOKCATEGORY
+_sym_db.RegisterFileDescriptor(DESCRIPTOR)
+
+RecommendationRequest = _reflection.GeneratedProtocolMessageType(
+    "RecommendationRequest",
+    (_message.Message,),
+    {
+        "DESCRIPTOR": _RECOMMENDATIONREQUEST,
+        "__module__": "recommendations_pb2"
+        # @@protoc_insertion_point(class_scope:RecommendationRequest)
+    },
+)
+_sym_db.RegisterMessage(RecommendationRequest)
+
+BookRecommendation = _reflection.GeneratedProtocolMessageType(
+    "BookRecommendation",
+    (_message.Message,),
+    {
+        "DESCRIPTOR": _BOOKRECOMMENDATION,
+        "__module__": "recommendations_pb2"
+        # @@protoc_insertion_point(class_scope:BookRecommendation)
+    },
+)
+_sym_db.RegisterMessage(BookRecommendation)
+
+RecommendationResponse = _reflection.GeneratedProtocolMessageType(
+    "RecommendationResponse",
+    (_message.Message,),
+    {
+        "DESCRIPTOR": _RECOMMENDATIONRESPONSE,
+        "__module__": "recommendations_pb2"
+        # @@protoc_insertion_point(class_scope:RecommendationResponse)
+    },
+)
+_sym_db.RegisterMessage(RecommendationResponse)
+
+
+_RECOMMENDATIONS = _descriptor.ServiceDescriptor(
+    name="Recommendations",
+    full_name="Recommendations",
+    file=DESCRIPTOR,
+    index=0,
+    serialized_options=None,
+    serialized_start=307,
+    serialized_end=386,
+    methods=[
+        _descriptor.MethodDescriptor(
+            name="Recommend",
+            full_name="Recommendations.Recommend",
+            index=0,
+            containing_service=None,
+            input_type=_RECOMMENDATIONREQUEST,
+            output_type=_RECOMMENDATIONRESPONSE,
+            serialized_options=None,
+        ),
+    ],
+)
+_sym_db.RegisterServiceDescriptor(_RECOMMENDATIONS)
+
+DESCRIPTOR.services_by_name["Recommendations"] = _RECOMMENDATIONS
+
+# @@protoc_insertion_point(module_scope)

python-microservices-with-grpc/marketplace/recommendations_pb2_grpc.py

+# flake8: noqa
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+import grpc
+
+import recommendations_pb2 as recommendations__pb2
+
+
+class RecommendationsStub(object):
+    """Missing associated documentation comment in .proto file"""
+
+    def __init__(self, channel):
+        """Constructor.
+
+        Args:
+            channel: A grpc.Channel.
+        """
+        self.Recommend = channel.unary_unary(
+            "/Recommendations/Recommend",
+            request_serializer=recommendations__pb2.RecommendationRequest.SerializeToString,
+            response_deserializer=recommendations__pb2.RecommendationResponse.FromString,
+        )
+
+
+class RecommendationsServicer(object):
+    """Missing associated documentation comment in .proto file"""
+
+    def Recommend(self, request, context):
+        """Missing associated documentation comment in .proto file"""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details("Method not implemented!")
+        raise NotImplementedError("Method not implemented!")
+
+
+def add_RecommendationsServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+        "Recommend": grpc.unary_unary_rpc_method_handler(
+            servicer.Recommend,
+            request_deserializer=recommendations__pb2.RecommendationRequest.FromString,
+            response_serializer=recommendations__pb2.RecommendationResponse.SerializeToString,
+        ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+        "Recommendations", rpc_method_handlers
+    )
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+# This class is part of an EXPERIMENTAL API.
+class Recommendations(object):
+    """Missing associated documentation comment in .proto file"""
+
+    @staticmethod
+    def Recommend(
+        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,
+            "/Recommendations/Recommend",
+            recommendations__pb2.RecommendationRequest.SerializeToString,
+            recommendations__pb2.RecommendationResponse.FromString,
+            options,
+            channel_credentials,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+        )

python-microservices-with-grpc/marketplace/requirements.txt

+flask ~= 1.1
+grpcio-tools ~= 1.30
+Jinja2 ~= 2.11
+pytest ~= 5.4

python-microservices-with-grpc/marketplace/templates/homepage.html

+<!doctype html>
+<html lang="en">
+<head>
+    <title>Online Books For You</title>
+</head>
+<body>
+    <h1>Mystery books you may like</h1>
+    <ul>
+    {% for book in recommendations %}
+        <li>{{ book.title }}</li>
+    {% endfor %}
+    </ul>
+</body>

python-microservices-with-grpc/protobufs/recommendations.proto

+syntax = "proto3";
+
+enum BookCategory {
+    MYSTERY = 0;
+    SCIENCE_FICTION = 1;
+    SELF_HELP = 2;
+}
+
+message RecommendationRequest {
+    int32 user_id = 1;
+    BookCategory category = 2;
+    int32 max_results = 3;
+}
+
+message BookRecommendation {
+    int32 id = 1;
+    string title = 2;
+}
+
+message RecommendationResponse {
+    repeated BookRecommendation recommendations = 1;
+}
+
+service Recommendations {
+    rpc Recommend (RecommendationRequest) returns (RecommendationResponse);
+}

python-microservices-with-grpc/recommendations/Dockerfile

+# syntax = docker/dockerfile:1.0-experimental
+# DOCKER_BUILDKIT=1 docker build . -f recommendations/Dockerfile -t recommendations --secret id=ca.key,src=ca.key
+
+FROM python
+
+RUN mkdir /service
+COPY protobufs/ /service/protobufs/
+COPY recommendations/ /service/recommendations/
+COPY ca.pem /service/recommendations/
+
+WORKDIR /service/recommendations
+RUN pip install -r requirements.txt
+RUN python -m grpc_tools.protoc -I ../protobufs --python_out=. \
+           --grpc_python_out=. ../protobufs/recommendations.proto
+RUN openssl req -nodes -newkey rsa:4096 -subj /CN=recommendations \
+                -keyout server.key -out server.csr
+RUN --mount=type=secret,id=ca.key \
+    openssl x509 -req -in server.csr -CA ca.pem -CAkey /run/secrets/ca.key \
+                 -set_serial 1 -out server.pem
+
+EXPOSE 50051
+ENTRYPOINT [ "python", "recommendations.py" ]

python-microservices-with-grpc/recommendations/recommendations.py

+from concurrent import futures
+import random
+
+import grpc
+from grpc_interceptor import ExceptionToStatusInterceptor
+from grpc_interceptor.exceptions import NotFound
+
+from recommendations_pb2 import (
+    BookCategory,
+    BookRecommendation,
+    RecommendationResponse,
+)
+import recommendations_pb2_grpc
+
+books_by_category = {
+    BookCategory.MYSTERY: [
+        BookRecommendation(id=1, title="The Maltese Falcon"),
+        BookRecommendation(id=2, title="Murder on the Orient Express"),
+        BookRecommendation(id=3, title="The Hound of the Baskervilles"),
+    ],
+    BookCategory.SCIENCE_FICTION: [
+        BookRecommendation(id=4, title="The Hitchhiker's Guide To The Galaxy"),
+        BookRecommendation(id=5, title="Ender's Game"),
+        BookRecommendation(id=6, title="The Dune Chronicles"),
+    ],
+    BookCategory.SELF_HELP: [
+        BookRecommendation(
+            id=7, title="The 7 Habits of Highly Effective People"
+        ),
+        BookRecommendation(
+            id=8, title="How to Win Friends and Influence People"
+        ),
+        BookRecommendation(id=9, title="Man’s Search for Meaning"),
+    ],
+}
+
+
+class RecommendationService(recommendations_pb2_grpc.RecommendationsServicer):
+    def Recommend(self, request, context):
+        if request.category not in books_by_category:
+            raise NotFound("Category not found")
+
+        books_for_category = books_by_category[request.category]
+        num_results = min(request.max_results, len(books_for_category))
+        books_to_recommend = random.sample(books_for_category, num_results)
+
+        return RecommendationResponse(recommendations=books_to_recommend)
+
+
+def serve():
+    interceptors = [ExceptionToStatusInterceptor()]
+    server = grpc.server(
+        futures.ThreadPoolExecutor(max_workers=10), interceptors=interceptors
+    )
+    recommendations_pb2_grpc.add_RecommendationsServicer_to_server(
+        RecommendationService(), server
+    )
+
+    with open("server.key", "rb") as fp:
+        server_key = fp.read()
+    with open("server.pem", "rb") as fp:
+        server_cert = fp.read()
+    with open("ca.pem", "rb") as fp:
+        ca_cert = fp.read()
+
+    creds = grpc.ssl_server_credentials(
+        [(server_key, server_cert)],
+        root_certificates=ca_cert,
+        require_client_auth=True,
+    )
+    server.add_secure_port("[::]:443", creds)
+    server.start()
+    server.wait_for_termination()
+
+
+if __name__ == "__main__":
+    serve()

python-microservices-with-grpc/recommendations/recommendations_pb2.py

+# -*- coding: utf-8 -*-
+# flake8: noqa
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: recommendations.proto
+
+from google.protobuf.internal import enum_type_wrapper
+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
+
+# @@protoc_insertion_point(imports)
+
+_sym_db = _symbol_database.Default()
+
+
+DESCRIPTOR = _descriptor.FileDescriptor(
+    name="recommendations.proto",
+    package="",
+    syntax="proto3",
+    serialized_options=None,
+    serialized_pb=b'\n\x15recommendations.proto"^\n\x15RecommendationRequest\x12\x0f\n\x07user_id\x18\x01 \x01(\x05\x12\x1f\n\x08\x63\x61tegory\x18\x02 \x01(\x0e\x32\r.BookCategory\x12\x13\n\x0bmax_results\x18\x03 \x01(\x05"/\n\x12\x42ookRecommendation\x12\n\n\x02id\x18\x01 \x01(\x05\x12\r\n\x05title\x18\x02 \x01(\t"F\n\x16RecommendationResponse\x12,\n\x0frecommendations\x18\x01 \x03(\x0b\x32\x13.BookRecommendation*?\n\x0c\x42ookCategory\x12\x0b\n\x07MYSTERY\x10\x00\x12\x13\n\x0fSCIENCE_FICTION\x10\x01\x12\r\n\tSELF_HELP\x10\x02\x32O\n\x0fRecommendations\x12<\n\tRecommend\x12\x16.RecommendationRequest\x1a\x17.RecommendationResponseb\x06proto3',
+)
+
+_BOOKCATEGORY = _descriptor.EnumDescriptor(
+    name="BookCategory",
+    full_name="BookCategory",
+    filename=None,
+    file=DESCRIPTOR,
+    values=[
+        _descriptor.EnumValueDescriptor(
+            name="MYSTERY",
+            index=0,
+            number=0,
+            serialized_options=None,
+            type=None,
+        ),
+        _descriptor.EnumValueDescriptor(
+            name="SCIENCE_FICTION",
+            index=1,
+            number=1,
+            serialized_options=None,
+            type=None,
+        ),
+        _descriptor.EnumValueDescriptor(
+            name="SELF_HELP",
+            index=2,
+            number=2,
+            serialized_options=None,
+            type=None,
+        ),
+    ],
+    containing_type=None,
+    serialized_options=None,
+    serialized_start=242,
+    serialized_end=305,
+)
+_sym_db.RegisterEnumDescriptor(_BOOKCATEGORY)
+
+BookCategory = enum_type_wrapper.EnumTypeWrapper(_BOOKCATEGORY)
+MYSTERY = 0
+SCIENCE_FICTION = 1
+SELF_HELP = 2
+
+
+_RECOMMENDATIONREQUEST = _descriptor.Descriptor(
+    name="RecommendationRequest",
+    full_name="RecommendationRequest",
+    filename=None,
+    file=DESCRIPTOR,
+    containing_type=None,
+    fields=[
+        _descriptor.FieldDescriptor(
+            name="user_id",
+            full_name="RecommendationRequest.user_id",
+            index=0,
+            number=1,
+            type=5,
+            cpp_type=1,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+        _descriptor.FieldDescriptor(
+            name="category",
+            full_name="RecommendationRequest.category",
+            index=1,
+            number=2,
+            type=14,
+            cpp_type=8,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+        _descriptor.FieldDescriptor(
+            name="max_results",
+            full_name="RecommendationRequest.max_results",
+            index=2,
+            number=3,
+            type=5,
+            cpp_type=1,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+    ],
+    extensions=[],
+    nested_types=[],
+    enum_types=[],
+    serialized_options=None,
+    is_extendable=False,
+    syntax="proto3",
+    extension_ranges=[],
+    oneofs=[],
+    serialized_start=25,
+    serialized_end=119,
+)
+
+
+_BOOKRECOMMENDATION = _descriptor.Descriptor(
+    name="BookRecommendation",
+    full_name="BookRecommendation",
+    filename=None,
+    file=DESCRIPTOR,
+    containing_type=None,
+    fields=[
+        _descriptor.FieldDescriptor(
+            name="id",
+            full_name="BookRecommendation.id",
+            index=0,
+            number=1,
+            type=5,
+            cpp_type=1,
+            label=1,
+            has_default_value=False,
+            default_value=0,
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+        _descriptor.FieldDescriptor(
+            name="title",
+            full_name="BookRecommendation.title",
+            index=1,
+            number=2,
+            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,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+    ],
+    extensions=[],
+    nested_types=[],
+    enum_types=[],
+    serialized_options=None,
+    is_extendable=False,
+    syntax="proto3",
+    extension_ranges=[],
+    oneofs=[],
+    serialized_start=121,
+    serialized_end=168,
+)
+
+
+_RECOMMENDATIONRESPONSE = _descriptor.Descriptor(
+    name="RecommendationResponse",
+    full_name="RecommendationResponse",
+    filename=None,
+    file=DESCRIPTOR,
+    containing_type=None,
+    fields=[
+        _descriptor.FieldDescriptor(
+            name="recommendations",
+            full_name="RecommendationResponse.recommendations",
+            index=0,
+            number=1,
+            type=11,
+            cpp_type=10,
+            label=3,
+            has_default_value=False,
+            default_value=[],
+            message_type=None,
+            enum_type=None,
+            containing_type=None,
+            is_extension=False,
+            extension_scope=None,
+            serialized_options=None,
+            file=DESCRIPTOR,
+        ),
+    ],
+    extensions=[],
+    nested_types=[],
+    enum_types=[],
+    serialized_options=None,
+    is_extendable=False,
+    syntax="proto3",
+    extension_ranges=[],
+    oneofs=[],
+    serialized_start=170,
+    serialized_end=240,
+)
+
+_RECOMMENDATIONREQUEST.fields_by_name["category"].enum_type = _BOOKCATEGORY
+_RECOMMENDATIONRESPONSE.fields_by_name[
+    "recommendations"
+].message_type = _BOOKRECOMMENDATION
+DESCRIPTOR.message_types_by_name[
+    "RecommendationRequest"
+] = _RECOMMENDATIONREQUEST
+DESCRIPTOR.message_types_by_name["BookRecommendation"] = _BOOKRECOMMENDATION
+DESCRIPTOR.message_types_by_name[
+    "RecommendationResponse"
+] = _RECOMMENDATIONRESPONSE
+DESCRIPTOR.enum_types_by_name["BookCategory"] = _BOOKCATEGORY
+_sym_db.RegisterFileDescriptor(DESCRIPTOR)
+
+RecommendationRequest = _reflection.GeneratedProtocolMessageType(
+    "RecommendationRequest",
+    (_message.Message,),
+    {
+        "DESCRIPTOR": _RECOMMENDATIONREQUEST,
+        "__module__": "recommendations_pb2"
+        # @@protoc_insertion_point(class_scope:RecommendationRequest)
+    },
+)
+_sym_db.RegisterMessage(RecommendationRequest)
+
+BookRecommendation = _reflection.GeneratedProtocolMessageType(
+    "BookRecommendation",
+    (_message.Message,),
+    {
+        "DESCRIPTOR": _BOOKRECOMMENDATION,
+        "__module__": "recommendations_pb2"
+        # @@protoc_insertion_point(class_scope:BookRecommendation)
+    },
+)
+_sym_db.RegisterMessage(BookRecommendation)
+
+RecommendationResponse = _reflection.GeneratedProtocolMessageType(
+    "RecommendationResponse",
+    (_message.Message,),
+    {
+        "DESCRIPTOR": _RECOMMENDATIONRESPONSE,
+        "__module__": "recommendations_pb2"
+        # @@protoc_insertion_point(class_scope:RecommendationResponse)
+    },
+)
+_sym_db.RegisterMessage(RecommendationResponse)
+
+
+_RECOMMENDATIONS = _descriptor.ServiceDescriptor(
+    name="Recommendations",
+    full_name="Recommendations",
+    file=DESCRIPTOR,
+    index=0,
+    serialized_options=None,
+    serialized_start=307,
+    serialized_end=386,
+    methods=[
+        _descriptor.MethodDescriptor(
+            name="Recommend",
+            full_name="Recommendations.Recommend",
+            index=0,
+            containing_service=None,
+            input_type=_RECOMMENDATIONREQUEST,
+            output_type=_RECOMMENDATIONRESPONSE,
+            serialized_options=None,
+        ),
+    ],
+)
+_sym_db.RegisterServiceDescriptor(_RECOMMENDATIONS)
+
+DESCRIPTOR.services_by_name["Recommendations"] = _RECOMMENDATIONS
+
+# @@protoc_insertion_point(module_scope)

python-microservices-with-grpc/recommendations/recommendations_pb2_grpc.py

+# flake8: noqa
+# Generated by the gRPC Python protocol compiler plugin. DO NOT EDIT!
+import grpc
+
+import recommendations_pb2 as recommendations__pb2
+
+
+class RecommendationsStub(object):
+    """Missing associated documentation comment in .proto file"""
+
+    def __init__(self, channel):
+        """Constructor.
+
+        Args:
+            channel: A grpc.Channel.
+        """
+        self.Recommend = channel.unary_unary(
+            "/Recommendations/Recommend",
+            request_serializer=recommendations__pb2.RecommendationRequest.SerializeToString,
+            response_deserializer=recommendations__pb2.RecommendationResponse.FromString,
+        )
+
+
+class RecommendationsServicer(object):
+    """Missing associated documentation comment in .proto file"""
+
+    def Recommend(self, request, context):
+        """Missing associated documentation comment in .proto file"""
+        context.set_code(grpc.StatusCode.UNIMPLEMENTED)
+        context.set_details("Method not implemented!")
+        raise NotImplementedError("Method not implemented!")
+
+
+def add_RecommendationsServicer_to_server(servicer, server):
+    rpc_method_handlers = {
+        "Recommend": grpc.unary_unary_rpc_method_handler(
+            servicer.Recommend,
+            request_deserializer=recommendations__pb2.RecommendationRequest.FromString,
+            response_serializer=recommendations__pb2.RecommendationResponse.SerializeToString,
+        ),
+    }
+    generic_handler = grpc.method_handlers_generic_handler(
+        "Recommendations", rpc_method_handlers
+    )
+    server.add_generic_rpc_handlers((generic_handler,))
+
+
+# This class is part of an EXPERIMENTAL API.
+class Recommendations(object):
+    """Missing associated documentation comment in .proto file"""
+
+    @staticmethod
+    def Recommend(
+        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,
+            "/Recommendations/Recommend",
+            recommendations__pb2.RecommendationRequest.SerializeToString,
+            recommendations__pb2.RecommendationResponse.FromString,
+            options,
+            channel_credentials,
+            call_credentials,
+            compression,
+            wait_for_ready,
+            timeout,
+            metadata,
+        )

python-microservices-with-grpc/recommendations/recommendations_test.py

+from recommendations import RecommendationService
+
+from recommendations_pb2 import BookCategory, RecommendationRequest
+
+
+def test_recommendations():
+    service = RecommendationService()
+    request = RecommendationRequest(
+        user_id=1, category=BookCategory.MYSTERY, max_results=1
+    )
+    response = service.Recommend(request, None)
+    assert len(response.recommendations) == 1

python-microservices-with-grpc/recommendations/requirements.txt

+grpc-interceptor ~= 0.11.0
+grpcio-tools ~= 1.30
+pytest ~= 5.4