在Azure上托管gRPC服务器后，gRPC客户端无法与gRPC服务器通信

Question

下面的代码片段显示了如何在gRPC AspNet核心应用程序中启用gRPC web：

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddGrpc();
    }

    // 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();
        }
        else
        {
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseDefaultFiles();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseGrpcWeb();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapGrpcService<SubmissionService>().EnableGrpcWeb();
        });
    }
}

客户端应用程序的代码如下所示：

public static async Task SendSomethingAsync(string payload, ILoggerFactory loggerFactory)
        {
            const string url = "https://MASKED.azurewebsites.net/";
            //const string url = "https://localhost:44308";
            AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);
            var handler = new GrpcWebHandler(GrpcWebMode.GrpcWebText, new HttpClientHandler());
            using var channel = GrpcChannel.ForAddress(url, new GrpcChannelOptions
            {
                HttpClient = new HttpClient(handler),
                LoggerFactory = loggerFactory
            });

            var client = new TestgRPC.gRPC.PayloadSubmission.PayloadSubmissionClient(channel);
            var submitted = await client.SubmitAsync(new SubmissionRequest
            {
                ClientKey = "678",
                ConnectionId = "abcdef",
                UserId = "3",
                MyObjectPayload= payload,
            });

            Console.WriteLine($"Submitted: {submitted}");
        }

Answer 1

问题是我们需要将应用程序部署为一个自包含的应用程序。显然，安装在Azure应用程序服务上的默认。NET Core3.1不能容纳gRPC-web应用程序。