Django gRPC 应用

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官方文档: https://djangogrpcframework.readthedocs.io/en/latest/index.html

项目设置

创建一个名为的新Django项目quickstart，然后启动一个名为的新应用 account：

# Create a virtual environment
python3 -m venv env
source env/bin/activate
# Install Django and Django gRPC framework
pip install django
pip install djangorestframework
pip install djangogrpcframework
pip install grpcio
pip install grpcio-tools
# Create a new project and a new application
django-admin startproject quickstart
cd quickstart
django-admin startapp account

现在同步数据库：

python manage.py migrate

 

更新设置

添加django_grpc_framework到INSTALLED_APPS，设置模块位于 quickstart/settings.py：

INSTALLED_APPS = [
    ...
    'django_grpc_framework',
]

 

定义原型

我们的第一步是定义gRPC服务和消息，在quickstart/account.proto旁边创建一个文件 quickstart/manage.py：

syntax = "proto3";

package account;

import "google/protobuf/empty.proto";

service UserController {
    rpc List(UserListRequest) returns (stream User) {}
    rpc Create(User) returns (User) {}
    rpc Retrieve(UserRetrieveRequest) returns (User) {}
    rpc Update(User) returns (User) {}
    rpc Destroy(User) returns (google.protobuf.Empty) {}
}

message User {
    int32 id = 1;
    string username = 2;
    string email = 3;
    repeated int32 groups = 4;
}

message UserListRequest {
}

message UserRetrieveRequest {
    int32 id = 1;
}

或者您可以根据User模型自动生成它：

 
python manage.py generateproto --model django.contrib.auth.models.User --fields id,username,email,groups --file account.proto

接下来，我们需要从quickstart目录生成gRPC代码，运行：

python -m grpc_tools.protoc --proto_path=./ --python_out=./ --grpc_python_out=./ ./account.proto

编写串行

然后，我们将定义一个序列化器，让我们创建一个名为的新模块 account/serializers.py：

from django.contrib.auth.models import User
from django_grpc_framework import proto_serializers
import account_pb2

class UserProtoSerializer(proto_serializers.ModelProtoSerializer):
    class Meta:
        model = User
        proto_class = account_pb2.User
        fields = ['id', 'username', 'email', 'groups']

 

写作服务

现在我们编写一些服务，创建account/services.py：

from django.contrib.auth.models import User
from django_grpc_framework import generics
from account.serializers import UserProtoSerializer

class UserService(generics.ModelService):
    """
    gRPC service that allows users to be retrieved or updated.
    """
    queryset = User.objects.all().order_by('-date_joined')
    serializer_class = UserProtoSerializer

 

注册处理程序

好的，让我们连接gRPC处理程序，编辑quickstart/urls.py：

import account_pb2_grpc
from account.services import UserService

urlpatterns = []


def grpc_handlers(server):
    account_pb2_grpc.add_UserControllerServicer_to_server(UserService.as_servicer(), server)

 

完成后，项目布局应如下所示：

.
./quickstart
./quickstart/asgi.py
./quickstart/__init__.py
./quickstart/settings.py
./quickstart/urls.py
./quickstart/wsgi.py
./manage.py
./account
./account/migrations
./account/migrations/__init__.py
./account/services.py
./account/models.py
./account/serializers.py
./account/__init__.py
./account/apps.py
./account/admin.py
./account/tests.py
./account.proto
./account_pb2_grpc.py
./account_pb2.py

拨打我们的服务

用开发模式启动服务器：

python manage.py grpcrunserver --dev

 

现在，我们可以从gRPC客户端访问我们的服务：

import grpc
import account_pb2
import account_pb2_grpc

with grpc.insecure_channel('localhost:50051') as channel:
    stub = account_pb2_grpc.UserControllerStub(channel)
    for user in stub.List(account_pb2.UserListRequest()):
        print(user, end='')

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