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Dapr 运用

Zhang_Xiang 人气:1

Dapr 运用

  • 前置条件
    • Docker
    • Win10

Dapr 部署

本文将采用本地部署的方式。

安装 Dapr CLI

打开 Windows PowerShell 或 cmd ，运行以下命令以安装 Dapr CLI，并添加安装路径到系统环境变量中。

powershell -Command "iwr -useb https://raw.githubusercontent.comhttps://img.qb5200.com/download-x/dapr/cli/master/install/install.ps1 | iex"

这里安装可能会失败。如果失败可以手动安装。

  • 打开 Dapr 发布页面下载 dapr_windows_amd64.zip
  • 解压文件 zip 文件
  • 把解压后的文件拷贝到 C:\dapr 中

安装 MySql

Docker 启动 Mysql

docker run --name mysqltest -e MYSQL_ROOT_PASSWORD=123456 -d mysql

使用 Dapr CLI 安装 Darp runtime

在 Windows PowerShell 或 cmd 中使用命令 dapr init 以安装 Dapr。

同时可以在 Docker 中查看 Dapr 容器。

至此，一个本地 Dapr 服务搭建完成。

使用 Asp.Net Core 搭建 ProductService 服务

ProductService 提供两个服务

  • 获取所有产品集合
  • 添加产品

  1. 使用 ASP.Net Core 创建 ProductService ，具体参考源码

  2. Dapr 启动 ProductService

    dapr run --app-id productService --app-port 5000 dotnet run

  3. 获取所有产品集合，使用 curl 命令

    curl -X GET http://localhost:5000/getlist

    或者

    curl -X GET http://localhost:54680/v1.0/invoke/productService/method/getlist

  4. 添加一个产品

    curl -X POST https://localhost:5001/product -H "Content-Type: application/json" -d "{ \"id\": \"14a3611d-1561-455f-9c72-381eed2f6ee3\" }"

  5. 重点，通过 Dapr 添加一个产品，先看添加产品的代码

     /// <summary>
 /// 创建产品
 /// </summary>
 /// <param name="productCreate">产品创建模型</param>
 /// <returns></returns>
 [Topic("product")]
 [HttpPost("product")]
 public async Task<bool> CreateProduct(ProductCreate productCreate)
 {
     _productContext.Products.Add(new Product
     {
         ProductID = productCreate.ID
     });
     return await _productContext.SaveChangesAsync() == 1;
 }

    • 使用 Dapr cli 发布事件

       dapr invoke -a productService -m product -p "{\"id\":\"b1ccf14a-408a-428e-b0f0-06b97cbe4135\"}"

      输出为：

      true
App invoked successfully

    • 使用 curl 命令直接请求 ProductService 地址

      curl -X POST http://localhost:5000/product -H "Content-Type: application/json" -d "{ \"id\": \"14a3611d-1561-455f-9c72-381eed2f64e3\" }"

      输出为：

      true

    • 使用 curl 命令通过 Dapr runtime

      curl -X POST http://localhost:54680/v1.0/invoke/productService/method/product -H "Content-Type: application/json" -d "{ \"id\": \"14a3611d-1561-455f-9c72-381eed2f54e3\" }"

      输出为：

      true

注意：

  • Dapr 使用 App 端口号应与服务端口号相同，例如：ASP.Net Core 服务端口号为5000，则在使用 Dapr 托管应用程序时的端口号也应使用 5000

至此， ProductService 创建完成。

使用 Golang 创建 gRPC Server

  1. 创建 Server

    package main

import (
    "context"
    "fmt"
    "log"
    "net"

    "github.com/golang/protobuf/ptypes/any"
    "github.com/golang/protobuf/ptypes/empty"

    pb "github.comhttps://img.qb5200.com/download-x/dapr/go-sdkhttps://img.qb5200.com/download-x/daprclient"
    "google.golang.org/grpc"
)

// server is our user app
type server struct {
}

func main() {
    // create listiner
    lis, err := net.Listen("tcp", ":4000")
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }

    // create grpc server
    s := grpc.NewServer()
    pb.RegisterDaprClientServer(s, &server{})

    fmt.Println("Client starting...")

    // and start...
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}

// Sample method to invoke
func (s *server) MyMethod() string {
    return "Hi there!"
}

// This method gets invoked when a remote service has called the app through Dapr
// The payload carries a Method to identify the method, a set of metadata properties and an optional payload
func (s *server) OnInvoke(ctx context.Context, in *pb.InvokeEnvelope) (*any.Any, error) {
    var response string

    fmt.Println(fmt.Sprintf("Got invoked with: %s", string(in.Data.Value)))

    switch in.Method {
    case "MyMethod":
        response = s.MyMethod()
    }
    return &any.Any{
        Value: []byte(response),
    }, nil
}

// Dapr will call this method to get the list of topics the app wants to subscribe to. In this example, we are telling Dapr
// To subscribe to a topic named TopicA
func (s *server) GetTopicSubscriptions(ctx context.Context, in *empty.Empty) (*pb.GetTopicSubscriptionsEnvelope, error) {
    return &pb.GetTopicSubscriptionsEnvelope{
        Topics: []string{"TopicA"},
    }, nil
}

// Dapper will call this method to get the list of bindings the app will get invoked by. In this example, we are telling Dapr
// To invoke our app with a binding named storage
func (s *server) GetBindingsSubscriptions(ctx context.Context, in *empty.Empty) (*pb.GetBindingsSubscriptionsEnvelope, error) {
    return &pb.GetBindingsSubscriptionsEnvelope{
        Bindings: []string{"storage"},
    }, nil
}

// This method gets invoked every time a new event is fired from a registerd binding. The message carries the binding name, a payload and optional metadata
func (s *server) OnBindingEvent(ctx context.Context, in *pb.BindingEventEnvelope) (*pb.BindingResponseEnvelope, error) {
    fmt.Println("Invoked from binding")
    return &pb.BindingResponseEnvelope{}, nil
}

// This method is fired whenever a message has been published to a topic that has been subscribed. Dapr sends published messages in a CloudEvents 0.3 envelope.
func (s *server) OnTopicEvent(ctx context.Context, in *pb.CloudEventEnvelope) (*empty.Empty, error) {
    fmt.Println("Topic message arrived")
    return &empty.Empty{}, nil
}

  2. 使用 Dapr 命令启动 StorageService

     dapr run --app-id client --protocol grpc --app-port 4000 go run main.go

注意：

  • Dapr 使用 App 端口号应与服务端口号相同，使用 --protocal grpc 指定通讯协议为 grpc 。此外，OnInvoke 中的 switch 方法用于调用者路由。

使用 ASP.NET Core 创建 StorageService

  1. 使用 NuGet 获取程序管理包控制台安装以下包
    • Dapr.AspNetCore
    • Dapr.Client.Grpc
    • Grpc.AspNetCore
    • Grpc.Net.Client
    • Grpc.Tools

  2. Startup.cs 文件中修改代码如下：

    /// <summary>
/// This method gets called by the runtime. Use this method to add services to the container.
/// </summary>
/// <param name="services">Services.</param>
public void ConfigureServices(IServiceCollection services)
{
    services.AddControllers().AddDapr();
    services.AddDbContextPool<StorageContext>(options => { options.UseMySql(Configuration.GetConnectionString("MysqlConnection")); });
}
     /// <summary>
/// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
/// </summary>
/// <param name="app">app.</param>
/// <param name="env">env.</param>
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }

    app.UseRouting();
    app.UseCloudEvents();

    app.UseAuthorization();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapSubscribeHandler();
        endpoints.MapControllers();
    });
}

  3. 添加 StorageController.cs 文件，内容如下

    using System;
using System.Linq;
using System.Threading.Tasks;
using Dapr.Client.Grpc;
using Google.Protobuf;
using Grpc.Net.Client;
using Microsoft.AspNetCore.Mvc;
using StorageService.Api.Entities;

namespace StorageService.Api.Controllers
{
    [ApiController]
    public class StorageController : ControllerBase
    {
        private readonly StorageContext _storageContext;

        public StorageController(StorageContext storageContext)
        {
            _storageContext = storageContext;
        }

        /// <summary>
        /// 初始化仓库.
        /// </summary>
        /// <returns>是否成功.</returns>
        [HttpGet("InitialStorage")]
        public async Task<bool> InitialStorage()
        {
            string defaultPort = Environment.GetEnvironmentVariable("DAPR_GRPC_PORT") ?? "54681";

            // Set correct switch to make insecure gRPC service calls. This switch must be set before creating the GrpcChannel.
            AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);

            // Create Client
            string daprUri = $"http://127.0.0.1:{defaultPort}";
            GrpcChannel channel = GrpcChannel.ForAddress(daprUri);
            var client = new Dapr.Client.Grpc.Dapr.DaprClient(channel);
            Console.WriteLine(daprUri);

            InvokeServiceResponseEnvelope result = await client.InvokeServiceAsync(new InvokeServiceEnvelope
            {
                Method = "MyMethod",
                Id = "client",
                Data = new Google.Protobuf.WellKnownTypes.Any
                {
                    Value = ByteString.CopyFromUtf8("Hello ProductService")
                }
            });
            Console.WriteLine("this is call result:" + result.Data.Value.ToStringUtf8());
            //var productResult = result.Data.Unpack<ProductList.V1.ProductList>();
            //Console.WriteLine("this is call result:" + productResult.Results.FirstOrDefault());
            return true;
        }

        /// <summary>
        /// 修改库存
        /// </summary>
        /// <param name="storage"></param>
        /// <returns></returns>
        [HttpPut("Reduce")]
        public bool Reduce(Storage storage)
        {
            Storage storageFromDb = _storageContext.Storage.FirstOrDefault(q => q.ProductID.Equals(storage.ProductID));
            if (storageFromDb == null)
            {
                return false;
            }

            if (storageFromDb.Amount <= storage.Amount)
            {
                return false;
            }

            storageFromDb.Amount -= storage.Amount;
            return true;
        }
    }
}

  4. 使用 Dapr cli 启用 StorageService 服务

    dapr run --app-id storageService --app-port 5003 dotnet run

  5. 使用 curl 命令访问 StorageService InitialStorage 方法

    curl -X GET http://localhost:56349/v1.0/invoke/storageService/method/InitialStorage

    输入

    true

    其中打印信息为：

    this is call result:Hi there!

注意：

  • Dapr 使用 App 端口号应与服务端口号相同，例如：ASP.Net Core 服务端口号为5003，则在使用 Dapr 托管应用程序时的端口号也应使用 5003，在 Client.InvokeServiceAsync 中的 Id 指被调用方的 App-Id ,Method 指被调用方方法名称。参考 Go Server 中 OnInvoke 方法的 Switch 。

源码地址

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