Dapr DotNet5 HTTP 呼叫

Zhang_Xiang發表於2020-11-27
HTTP

Dapr DotNet5 HTTP 呼叫

版本介紹

  • Dotnet 版本：5.0.100
  • Dapr dotnet 版本：0.12.0-preview01

注意: Asp.Net Core 專案中的 launchSettings.json 檔案，該檔案的中的埠號應和 darp --app-port 埠號相同，否則 dapr 無法正常啟動 Asp.Net Core 專案。

工程結構

3 個 .NET 5 專案，ClientA、ServiceB、ServiceC。1 個 .NET Standard 專案，Dtos 。Dtos 用於儲存各種傳輸模型。呼叫路徑如下圖所示。新建兩個 service 的意義在於展示 http 鏈路呼叫通過 dapr 如何實現。

graph LR; dotnet5-client-a--1-->dotnet5-service-b; dotnet5-service-b--2-->dotnet5-service-c; dotnet5-service-c--3-->dotnet5-service-b; dotnet5-service-b--4-->dotnet5-client-a;
  1. dotnet5-client-a 做為客戶端呼叫服務 dotnet5-service-b;
  2. dotnet5-service-b 做為服務中轉，既收來自 dotnet5-client-a 客戶端的請求，又發起對 dotnet5-service-c 的呼叫;
  3. dotnet5-service-c 響應 dotnet5-service-b 的請求；
  4. dotnet5-service-b 響應 dotnet5-client-a 的請求。

ServiceC

ServiceC 做為 http 呼叫鏈路呼叫終端只需監聽 http 呼叫埠。通過 nuget 包管理工具，選中->Show pre-release packages，搜尋 dapr ，選中 Dapr.AspNetCore 安裝包。

Startup

在 ConfigureServices(IServiceCollection services) 方法中通過鏈式呼叫 AddDapr() 方法註冊 Dapr 到 IOC 容器中。內容如下：

using System.Text.Json;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

namespace ServiceC
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddControllers().AddDapr().AddJsonOptions(options => {
                options.JsonSerializerOptions.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;
                options.JsonSerializerOptions.PropertyNameCaseInsensitive = true;
            }
            );
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }

            app.UseRouting();
            app.UseAuthorization();

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

HelloController

在 HelloController 中新增 Talk 方法，列印接收的資訊並告訴呼叫方當前服務是誰。具體內容如下：

[ApiController]
public class HelloController : Controller
{
    [HttpPost("talk")]
    public async Task<SomeResponseBody> Talk(SomeRequestBody someRequestBody)
    {
        Console.WriteLine(string.Format("{0}:{1}", someRequestBody.Id, someRequestBody.Time));
        return await Task.FromResult(new SomeResponseBody
        {
            Msg = "This is ServiceC"
        });
    }
}

launchSetting.json

profiles.ServiceC.applicationUrl 埠號一定要修改為 --app-port 相同的埠號，否則通過 dapr 啟動專案的時候無法正常啟動

{
  "$schema": "http://json.schemastore.org/launchsettings.json",
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
    "iisExpress": {
      "applicationUrl": "http://localhost:35737",
      "sslPort": 44379
    }
  },
  "profiles": {
    "IIS Express": {
      "commandName": "IISExpress",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    },
    "ServiceC": {
      "commandName": "Project",
      "launchBrowser": true,
      "launchUrl": "swagger",
      "applicationUrl": "http://localhost:9201",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

啟動

dapr run --app-id dotnet-server-c --app-port 9201 --dapr-http-port 3520 dotnet run

ServiceB

ServiceB 做為呼叫鏈中的一箇中轉節點，既要監聽服務，同時還要發起請求。由於 Dapr.AspNetCore 已經引用了 Dapr.Client 。因此不需要再次引用 Dapr.Client。

Startup

下面是 Dapr.AspNetCore AddDapr() 原始碼，從原始碼中可知 AddDapr() 方法向控制器中註冊 Dapr 整合。同時通過依賴注入容器註冊 DaprClient 。DaprClient 可以和 Dapr 執行時互動。比如 HTTP 呼叫,也正因為如此，ServiceB 的 Startup 檔案我們只需拷貝 ServiceC 的 Startup 檔案即可。原始碼如下：

/// <summary>
/// Provides extension methods for <see cref="IMvcBuilder" />.
/// </summary>
public static class DaprMvcBuilderExtensions
{
    /// <summary>
    /// Adds Dapr integration for MVC to the provided <see cref="IMvcBuilder" />.
    /// </summary>
    /// <param name="builder">The <see cref="IMvcBuilder" />.</param>
    /// <param name="configureClient">The (optional) <see cref="DaprClientBuilder" /> to use for configuring the DaprClient.</param>
    /// <returns>The <see cref="IMvcBuilder" /> builder.</returns>
    public static IMvcBuilder AddDapr(this IMvcBuilder builder, Action<DaprClientBuilder> configureClient = null)
    {
        if (builder is null)
        {
            throw new ArgumentNullException(nameof(builder));
        }

        // This pattern prevents registering services multiple times in the case AddDapr is called
        // by non-user-code.
        if (builder.Services.Any(s => s.ImplementationType == typeof(DaprMvcMarkerService)))
        {
            return builder;
        }

        builder.Services.AddDaprClient(configureClient);

        builder.Services.AddSingleton<DaprMvcMarkerService>();
        builder.Services.AddSingleton<IApplicationModelProvider, StateEntryApplicationModelProvider>();
        builder.Services.Configure<MvcOptions>(options =>
        {
            options.ModelBinderProviders.Insert(0, new StateEntryModelBinderProvider());
        });

        return builder;
    }

    private class DaprMvcMarkerService
    {
    }
}

HelloController

通過構造器注入 DaprClient 以發起 Http 呼叫 ServiceC 提供的服務。

[ApiController]
public class HelloController : ControllerBase
{

    private readonly DaprClient daprClient;

    public HelloController(DaprClient daprClient)
    {
        this.daprClient = daprClient;
    }

    [HttpPost("talk")]
    public async Task<SomeResponseBody> Talk(SomeRequestBody someRequestBody)
    {
        var data = new { Time = DateTime.Now.ToLongDateString(), Id = "This is Service C." };
        HTTPExtension httpExtension = new HTTPExtension()
        {
            Verb = HTTPVerb.Post
        };
        SomeResponseBody responseBody = await daprClient.InvokeMethodAsync<object, SomeResponseBody>("dotnet-server-c", "talk", data, httpExtension);

        Console.WriteLine(string.Format("{0}:{1} \n recieve message:{2}", someRequestBody.Id, someRequestBody.Time, responseBody.Msg));
        return await Task.FromResult(new SomeResponseBody
        {
            Msg = "This is ServiceB"
        });
    }

launchSetting.json

參考 ServiceC 更改埠號。

啟動

dapr run --app-id dotnet-server-b --app-port 9200 --dapr-http-port 3521 dotnet run

ClientA

ClientA 的目的是發起對 ServiceB 服務的呼叫，因此只需新增 Dapr.Client 用於和 Dapr 執行時互動即可。內容如下：

class Program
    {
        static async Task Main(string[] args)
        {
            var jsonOptions = new JsonSerializerOptions()
            {
                PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
                PropertyNameCaseInsensitive = true,
            };

            var client = new DaprClientBuilder()
                .UseJsonSerializationOptions(jsonOptions)
                .Build();

            var data = new { Time = DateTime.Now.ToLongDateString(), Id="This is Client A" };
            HTTPExtension httpExtension = new HTTPExtension()
            {
                Verb = HTTPVerb.Post
            };
            while (true)
            {
                var a = await client.InvokeMethodAsync<object, SomeResponseBody>("dotnet-server-b", "talk", data, httpExtension);
                Console.WriteLine(a.Msg);
                await Task.Delay(5 * 1000);
            }
        }
    }

每間隔 5 秒向 ServiceB 傳送一次請求。

啟動

dapr run --app-id dotnet5-http-client dotnet run

ClientA 接收內容:

== APP == This is ServiceB

SerivceB 接收內容:

== APP == This is Client A:2020年11月27日 星期五

== APP ==  recieve message:This is ServiceC

ServiceC 接收內容:

== APP == This is Service C.:2020年11月27日 星期五

總結

至此，DOTNET5 通過 dapr HTTP 呼叫的示例就結束了。

原始碼地址

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