Task getting canceled

[atulswagle]

Hi,

I am using Ocelot 23.4.3 and Net8.0.
My requirement is very simple, for all downstream API calls I want to add a specific response header and value I have to retrieve from another service.
So, I have added the following Handler, and I am trying to add the header in the HttpResponseMessage object.

public class AddVersionHandler : DelegatingHandler
{
    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {

        HttpResponseMessage response = null;

        try
        {
            response = await base.SendAsync(request, cancellationToken);
            if (response != null)
            {
                response.Headers.Add("X-App-Version", "1.1.1");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Failed to get response: {ex}");
            throw;
        }

        return response;
    }
}

I have registered the Handler as:

services.AddOcelot(Configuration)
    .AddDelegatingHandler<AddVersionHandler>(true);

Important point is if I comment out this delegating handler my app works fine.

I have tried to add the response header in OcelotPipelineConfiguration. I have added it in PreErrorResponderMiddleware after
await next.Invoke(); But I get the same issue.

Is there a better way to handle this?

Failed to get response:

System.Threading.Tasks.TaskCanceledException: The operation was canceled.
 ---> System.IO.IOException: Unable to read data from the transport connection: Operation canceled.
 ---> System.Net.Sockets.SocketException (125): Operation canceled
   --- End of inner exception stack trace ---
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.ThrowException(SocketError error, CancellationToken cancellationToken)
   at System.Net.Sockets.Socket.AwaitableSocketAsyncEventArgs.System.Threading.Tasks.Sources.IValueTaskSource<System.Int32>.GetResult(Int16 token)
   at System.Net.Security.SslStream.EnsureFullTlsFrameAsync[TIOAdapter](CancellationToken cancellationToken, Int32 estimatedSize)
   at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token)
   at System.Net.Security.SslStream.ReadAsyncInternal[TIOAdapter](Memory`1 buffer, CancellationToken cancellationToken)
   at System.Runtime.CompilerServices.PoolingAsyncValueTaskMethodBuilder`1.StateMachineBox`1.System.Threading.Tasks.Sources.IValueTaskSource<TResult>.GetResult(Int16 token)
   at System.Net.Http.HttpConnection.InitialFillAsync(Boolean async)
   at System.Net.Http.HttpConnection.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   --- End of inner exception stack trace ---
   at System.Net.Http.HttpConnection.SendAsync(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.DiagnosticsHandler.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at IVXCloud.Gateway.Handler.AddVersionHandler.SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) in C:\...Handler\AddVersionHandler.cs
info: Ocelot.Requester.Middleware.HttpRequesterMiddleware[0]

Another exception I see is this:

Exception thrown: 'System.NullReferenceException' in System.Private.CoreLib.dll: 'Object reference not set to an instance of an object.'
Stack trace:
 >   at Ocelot.Middleware.DownstreamResponse..ctor(HttpResponseMessage response)
 >   at Ocelot.Requester.Middleware.HttpRequesterMiddleware.<Invoke>d__3.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.Cache.Middleware.OutputCacheMiddleware.<Invoke>d__4.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.DownstreamUrlCreator.Middleware.DownstreamUrlCreatorMiddleware.<Invoke>d__8.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.LoadBalancer.Middleware.LoadBalancingMiddleware.<Invoke>d__3.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.DownstreamPathManipulation.Middleware.ClaimsToDownstreamPathMiddleware.<Invoke>d__3.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.QueryStrings.Middleware.ClaimsToQueryStringMiddleware.<Invoke>d__3.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.Headers.Middleware.ClaimsToHeadersMiddleware.<Invoke>d__3.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.Authorization.Middleware.AuthorizationMiddleware.<Invoke>d__4.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.Claims.Middleware.ClaimsToClaimsMiddleware.<Invoke>d__3.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Ocelot.Authentication.Middleware.AuthenticationMiddleware.<Invoke>d__2.MoveNext()
 >   at Microsoft.AspNetCore.MiddlewareAnalysis.AnalysisMiddleware.<Invoke>d__5.MoveNext()
 >   at Startup.<<Configure>b__10_2>d.MoveNext() in C:\..\Startup.cs

[raman-m]

System.IO.IOException: Unable to read data from the transport connection: Operation canceled.

It appears to be a transport level and protocol (scheme) error. Therefore, the downstream and HTTP version must be adjusted.
Refer to the documentation:

• DownstreamHttpVersion
• DownstreamHttpVersionPolicy

Also, please provide ocelot.json file! Sharing the handler code will not suffice for others to understand your app.

P. Additionally, please conduct a clean experiment to verify the use case without the delegating handler by temporarily removing or disabling. This will allow you to ensure a direct connection to the downstream service.

[raman-m]

Another exception I see is this:
'System.NullReferenceException' in System.Private.CoreLib.dll: 'Object reference not set to an instance of an object.'

Debug your custom middleware! 🤣

[atulswagle]

If I would comment out the response header call in the DelegateHandler, the whole application works fine.

So what I found is if the header name is not starting with "X-" then the application works fine. I am able to see the header element in the downstream calls. So I have updated the header element to "App-Version"