Dapr DotNet5 HTTP 调用

版本介绍

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

注意:

Asp.Net Core

项目中的 launchSettings.json 文件，该文件的中的端口号应和 darp –app-port 端口号相同，否则 dapr 无法正常启动

Asp.Net Core

项目。

工程结构

3 个 .NET 5 项目，ClientA、ServiceB、ServiceC。1 个 .NET Standard 项目，Dtos 。Dtos 用于存储各种传输模型。调用路径如下图所示。新建两个 service 的意义在于展示 http 链路调用通过 dapr 如何实现。

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 做为客户端调用服务 dotnet5-service-b;
2. dotnet5-service-b 做为服务中转，既收来自 dotnet5-client-a 客户端的请求，又发起对 dotnet5-service-c 的调用;
3. dotnet5-service-c 响应 dotnet5-service-b 的请求；
4. dotnet5-service-b 响应 dotnet5-client-a 的请求。

ServiceC

ServiceC 做为 http 调用链路调用终端只需监听 http 调用端口。通过 nuget 包管理工具，选中->Show pre-release packages，搜索 dapr ，选中 Dapr.AspNetCore 安装包。

Startup

在 ConfigureServices(IServiceCollection services) 方法中通过链式调用 AddDapr() 方法注册 Dapr 到 IOC 容器中。内容如下：

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 中添加 Talk 方法，打印接收的信息并告诉调用方当前服务是谁。具体内容如下：

[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 端口号一定要修改为 –app-port 相同的端口号，否则通过 dapr 启动项目的时候无法正常启动

{\"$schema\": \"http://json.schemastore.org/launchsettings.json\",\"iisSettings\": {\"windowsAuthentication\": false,\"anonymousAuthentication\": true,\"iisExpress\": {\"applicationUrl\": \"http://localhost:35737\",\"sslPort\": 44379}},\"profiles\": {\"IIS Express\": {15a8\"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\"}}}}

启动

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

ServiceB

ServiceB 做为调用链中的一个中转节点，既要监听服务，同时还要发起请求。由于

Dapr.AspNetCore

已经引用了

Dapr.Client

。因此不需要再次引用

Dapr.Client

。

Startup

下面是 Dapr.AspNetCore AddDapr() 源码，从源码中可知 AddDapr() 方法向控制器中注册 Dapr 集成。同时通过依赖注入容器注册 DaprClient 。DaprClient 可以和 Dapr 运行时交互。比如 HTTP 调用,也正因为如此，ServiceB 的 Startup 文件我们只需拷贝 ServiceC 的 Startup 文件即可。源码如下：

/// <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

通过构造器注入 DaprClient 以发起 Http 调用 ServiceC 提供的服务。

[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

参考 ServiceC 更改端口号。

启动

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

ClientA

ClientA 的目的是发起对 ServiceB 服务的调用，因此只需添加

Dapr.Client

用于和 Dapr 运行时交互即可。内容如下：

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);1489await Task.Delay(5 * 1000);}}}

每间隔 5 秒向 ServiceB 发送一次请求。

启动

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

ClientA 接收内容:

== APP == This is ServiceB

SerivceB 接收内容:

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

ServiceC 接收内容:

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

总结

至此，DOTNET5 通过 dapr HTTP 调用的示例就结束了。

源码地址