When making Grpc request over http in .net core creates following exception. I am using .net core 3.1

Question

Grpc.Core.RpcException: Status(StatusCode="Internal", Detail="Error starting gRPC call. HttpRequestException: An error occurred while sending the request. IOException: The request was aborted. Http2ConnectionException: The HTTP/2 server sent invalid data on the connection. HTTP/2 error code 'PROTOCOL_ERROR' (0x1).", DebugException="System.Net.Http.HttpRequestException: An error occurred while sending the request.
 ---> System.IO.IOException: The request was aborted.
 ---> System.Net.Http.Http2ConnectionException: The HTTP/2 server sent invalid data on the connection. HTTP/2 error code 'PROTOCOL_ERROR' (0x1).
   at System.Net.Http.Http2Connection.ReadFrameAsync(Boolean initialFrame)
   at System.Net.Http.Http2Connection.ProcessIncomingFramesAsync()
   --- End of inner exception stack trace ---
   at System.Net.Http.Http2Connection.Http2Stream.CheckResponseBodyState()
   at System.Net.Http.Http2Connection.Http2Stream.TryEnsureHeaders()
   at System.Net.Http.Http2Connection.Http2Stream.ReadResponseHeadersAsync(CancellationToken cancellationToken)
   at System.Net.Http.Http2Connection.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.Http2Connection.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithRetryAsync(HttpRequestMessage request, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.RedirectHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
   at Grpc.Net.Client.Internal.GrpcCall`2.RunCall(HttpRequestMessage request, Nullable`1 timeout)")
   at API.Controllers.WeatherForecastController.GetToken(UserDetails aUserDetails) in C:\DotNetCoreFramework -DBAgnostic\Test\API\Controllers\WeatherForecastController.cs:line 80
   at lambda_method(Closure , Object , Object[] )
   at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.SyncObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeActionMethodAsync()
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted).

      public UserDetails GetToken(UserDetails aUserDetails)
        {
            try
            {
                AppContext.SetSwitch(
                    "System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);

                using GrpcChannel channel1 = Grpc.Net.Client.GrpcChannel.ForAddress("http://localhost:5009/");
                var client1 = new Greeter.GreeterClient(channel1);
                UserDetails lUserDetails = client1.GetToken(aUserDetails);
                return lUserDetails;
            }catch(Exception ex) 
            {
                throw ex;
            }
         
        }```
port no in Grpc Service and client is same.

Answer 1

In my program.cs file i used UseUrls set to "http://localhost/5009" and in appsettings.json kestrel sections is as below

"Kestrel": {
    "Endpoints": {
      "HttpsInlineCertFile": {
        "Url": "https://localhost:5010",`enter code here`
        "Protocols": "Http2"
      }
      //,
      //"EndpointDefaults": {
      //  "Url": "http://localhost:5001",
      //  "Protocols": "Http2"
      //}
    }
  }

I removed kestrel section in appsettings.json everything worked fine

Answer 2

I could solve it in that way:

 public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseConfiguration(Configuration)
            .ConfigureKestrel(options =>
            {
                var (httpPort, grpcPort) = GetDefinedPorts();

                options.Listen(IPAddress.Any, httpPort, listenOptions =>
                {
                    listenOptions.Protocols = HttpProtocols.Http1AndHttp2;
                    listenOptions.UseHttps();
                });

                options.Listen(IPAddress.Any, grpcPort, listenOptions =>
                {
                    listenOptions.Protocols = HttpProtocols.Http2;
                });
            })
            .UseStartup<Startup>();

    private static (int httpPort, int grpcPort) GetDefinedPorts()
    {
        var grpcPort = Configuration.GetValue("GRPC_PORT", 5000);
        var port = Configuration.GetValue("PORT", 5001);

        return (port, grpcPort);
    }

Basically I configured two ports:

• An HTPPS port on 5001 that supports HTTP 1 and 2 and then I can open the 'localhost:50001/swagger'
• And another port that uses HTTP and supports only HTTP2 used for gRPC connections.

Answer 3

Combining the previous answers, I came up with this simple solution. You don't have to change any code, just appsettings.json . Example:

  "Kestrel": {
    "Endpoints": {
      "Http": {
        "Url": "http://localhost:5000"
      },
      "Https": {
        "Url": "https://localhost:5001"
      },
      "Grpc": {
        "Url": "http://localhost:5002",
        "Protocols": "Http2"
      }
    }
  }