I have a server to server calls and I use GRPC (with .net core 5) It's working and test in local.
After that, I have moved all the services to Kubernetes Pod (Docker Desktop) and also tested through the flow (with swagger post-call) and it's working there too.
Now for monitoring, I added ISTIO and added the label to my namespace "istio-injection=enabled" restarted all my pods and now all are having 2 containers inside each pod.
I tested the basic services (again swagger) and it's working. when it comes to testing the GRPC call. The call is failing from the caller side saying
Grpc.Core.RpcException: Status(StatusCode="Unavailable", Detail="upstream connect error or disconnect/reset before headers. reset reason: protocol error")
I checked the logs at GRPC server-side and it has no clue about this call and the service is just running. then I am kind of thinking that error is coming from the caller side whereas it is not able to or make a call to GRPC server.
The error detail:
Grpc.Core.RpcException: Status(StatusCode="Unavailable", Detail="upstream connect error or disconnect/reset before headers. reset reason: protocol error")
at Basket.API.GrpcServices.DiscountGrpcService.GetDiscount(String productName) in /src/Services/Basket/Basket.API/GrpcServices/DiscountGrpcService.cs:line 21
at Basket.API.Controllers.BasketController.UpdateBasket(ShoppingCart basket) in /src/Services/Basket/Basket.API/Controllers/BasketController.cs:line 47 at lambda_method7(Closure , Object )
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Obje
Again, I remove the Istio and tested and that's started working again (without changing anything) I added istio back and it started failing again. all other services are working with istio but not this call (This is only GRPC call I have).