Grpc.Core.RpcException：'状态（StatusCode="不可用"， Detail="空更新"，

Question

我的GRPC客户端在与我的服务器对话时抛出了以下异常。我推测这个异常意味着连接建立了，但是服务器出错了？

Grpc.Core.RpcException： 'Status（StatusCode=“Unavailable”， Detail=“Empty update”， DebugException=“Grpc.Core.Internal.CoreErrorDetailException： {”created“：”@1615327484.99300000“，”description“：”Failed to pick subchannel“，”file“：”......\src\core\ext\filters\client_channel\client_channel.cc“，”file_line“：5397，”referenced_errors“：[{”created“：”@1615327484.993000000“，”description“：”Empty update“，”file“：”......\src\core\ext\filters\client_channel\lb_policy\pick_first\pick_first.cc“，”file_line“：201，”grpc_status“：14}]}”）'

服务器的配置如下。我错过了什么吗？

public static IHostBuilder CreateHostBuilder(string[] args) =>
    Host.CreateDefaultBuilder(args)
        .ConfigureWebHostDefaults(webBuilder =>
        {
            webBuilder.ConfigureKestrel(options =>
            {
                options.Listen(IPAddress.Loopback, BINDING_PORT, configure => 
                { 
                    configure.UseHttps(GetCertificate());
                    configure.Protocols = Microsoft.AspNetCore.Server.Kestrel.Core.HttpProtocols.Http2;
                });
            });

            webBuilder.UseStartup<Startup>();
        }).UseWindowsService();

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }

    app.UseRouting();

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapGrpcService<LicenseService>().RequireHost($"*:{Program.BINDING_PORT}");

        endpoints.MapGet("/", async context =>
        {
            await context.Response.WriteAsync("Communication with gRPC endpoints must be made through a gRPC client. To learn how to create a client, visit: https://go.microsoft.com/fwlink/?linkid=2086909");
        });
    });
}

我注意到服务器通过BindService初始化，但服务Impl为空。这是意料之中的吗？

   public static void BindService(grpc::ServiceBinderBase serviceBinder, LicensesBase serviceImpl)
    {
      serviceBinder.AddMethod(__Method_GetLicense, serviceImpl == null ? null : new grpc::UnaryServerMethod<global::LicenseService.LicRequest, global::LicenseService.LicReply>(serviceImpl.GetLicense));
    }

Answer 1

我遇到了这个问题，直到我发现在创建客户端时，需要传递与创建服务器所用的证书文件相同的证书文件。

如果您没有传递任何证书文件，将使用默认的根证书文件，并且在我的机器上我没有任何根证书。我看到了关于无法加载任何根证书的相同错误。

此外，在创建到服务器的通道时，客户端必须使用用于创建服务器证书的相同“公用名”（www.example.com）。否则，服务器将拒绝 SSL 连接请求。

Answer 2

我想出了如何添加客户端日志记录，该日志记录生成了以下跟踪，指示证书预配不起作用。

Environment.SetEnvironmentVariable("GRPC_VERBOSITY", "DEBUG"); // enable traces


D0310 09:57:30.795179 Grpc.Core.Internal.UnmanagedLibrary Attempting to load native library "C:\Work\Petri\LicenseClient\LicTester\bin\x64\Debug\grpc_csharp_ext.x64.dll"
D0310 09:57:30.849621 Grpc.Core.Internal.NativeExtension gRPC native library loaded successfully.
D0310 09:57:30.858597 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "grpclb"
D0310 09:57:30.858597 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "priority_experimental"
D0310 09:57:30.858597 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "weighted_target_experimental"
D0310 09:57:30.858597 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "pick_first"
D0310 09:57:30.859599 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "round_robin"
D0310 09:57:30.859599 0 ..\..\..\src\core\ext\filters\client_channel\resolver\dns\c_ares\dns_resolver_ares.cc:491: Using ares dns resolver
D0310 09:57:30.860592 0 ..\..\..\src\core\ext\xds\certificate_provider_registry.cc:33: registering certificate provider factory for "file_watcher"
D0310 09:57:30.861589 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "cds_experimental"
D0310 09:57:30.861589 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "xds_cluster_impl_experimental"
D0310 09:57:30.861589 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "xds_cluster_resolver_experimental"
D0310 09:57:30.861589 0 ..\..\..\src\core\ext\filters\client_channel\lb_policy_registry.cc:42: registering LB policy factory for "xds_cluster_manager_experimental"
E0310 09:57:30.979025 0 ..\..\..\src\core\tsi\ssl_transport_security.cc:761: Could not load any root certificate.
E0310 09:57:30.979025 0 ..\..\..\src\core\tsi\ssl_transport_security.cc:1955: Cannot load server root certificates.
E0310 09:57:30.979025 0 ..\..\..\src\core\lib\security\security_connector\ssl\ssl_security_connector.cc:116: Handshaker factory creation failed with TSI_INVALID_ARGUMENT.
E0310 09:57:30.980022 0 ..\..\..\src\core\ext\transport\chttp2\client\secure\secure_channel_create.cc:107: Failed to create secure subchannel for secure name '127.0.0.1:59740'
E0310 09:57:30.980022 0 ..\..\..\src\core\ext\transport\chttp2\client\secure\secure_channel_create.cc:49: Failed to create channel args during subchannel creation.
E0310 09:57:31.027897 0 ..\..\..\src\core\tsi\ssl_transport_security.cc:761: Could not load any root certificate.
E0310 09:57:31.027897 0 ..\..\..\src\core\tsi\ssl_transport_security.cc:1955: Cannot load server root certificates.
E0310 09:57:31.030887 0 ..\..\..\src\core\lib\security\security_connector\ssl\ssl_security_connector.cc:116: Handshaker factory creation failed with TSI_INVALID_ARGUMENT.
E0310 09:57:31.040860 0 ..\..\..\src\core\ext\transport\chttp2\client\secure\secure_channel_create.cc:107: Failed to create secure subchannel for secure name '127.0.0.1:59740'
E0310 09:57:31.040860 0 ..\..\..\src\core\ext\transport\chttp2\client\secure\secure_channel_create.cc:49: Failed to create channel args during subchannel creation.