Key4.Grpc.ServerExceptionInterceptor

.NET Interceptor and middleware propagating errors between gRPC services.

Uses AutoWrapper for the returned object. Uses HttpExceptions for the mapping .net exception <-> HTTP status code.

Usage

Startup / Middleware registration

• Add the middleware to the configuration in Startup.cs of the client gRPC project. With an optional parameter ShowDetails (defaults to false).

 public void Configure(IApplicationBuilder app, IWebHostEnvironment env, IApiVersionDescriptionProvider provider)
 {
    // configurations
    app.UseK4GrpcException(options => options.ShowDetails = env.IsDevelopment() || env.IsStaging());
 }

• Add the interceptor to the gRPC configuration in Startup.cs of the server gRPC project.

public void ConfigureServices(IServiceCollection services)
{
    // configurations
    services.AddGrpc(options => options.Interceptors.Add<K4GrpcExceptionInterceptor>());
}

Example

Example of an error returned by a gRPC client when an exception is thrown at the server level.

• Example of error when ShowDetails is set to true.

{
    "statusCode": 403,
    "isError": true,
    "responseException": {
        "exceptionMessage": "No permissions for user",
        "details": "   at key4.Agency.BackOffice.API.Controllers.EchoController.ThrowAsync() in C:\\Repos\\key4.agency.docker\\key4.agency.api\\key4.Agency.BackOffice.API\\Controllers\\EchoController.cs:line 48\n   at lambda_method82(Closure , Object )\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\n",
        "status": 403,
        "type": "https://httpstatuses.com/403",
        "instance": "/v1/operations",
        "remoteException": {
            "message": "Status(StatusCode=\"PermissionDenied\", Detail=\"No permissions for user\")",
            "details": "   at key4.Service.Agency.Server.ThrowService.Throw(ThrowRequest request, ServerCallContext context) in C:\\Repos\\key4.agency.docker\\key4.service.agency\\1. Presentation\\key4.Service.Agency.Server\\Services\\ThrowService.cs:line 26\n   at Grpc.Shared.Server.UnaryServerMethodInvoker`3.ResolvedInterceptorInvoker(TRequest resolvedRequest, ServerCallContext resolvedContext)\n   at Grpc.Shared.Server.UnaryServerMethodInvoker`3.ResolvedInterceptorInvoker(TRequest resolvedRequest, ServerCallContext resolvedContext)\n   at key4.Grpc.ServerExceptionInterceptor.K4GrpcExceptionInterceptor.UnaryServerHandler[TRequest,TResponse](TRequest request, ServerCallContext context, UnaryServerMethod`2 continuation) in C:\\Repos\\key4.grpc\\key4.Grpc.ServerExceptionInterceptor\\K4GrpcExceptionInterceptor.cs:line 24"
        }
    }
}

• Example of error when ShowDetails is set to false.

{
    "statusCode": 403,
    "isError": true,
    "responseException": {
        "exceptionMessage": "No permissions for user",
        "status": 403,
        "type": "https://httpstatuses.com/403",
        "instance": "/v1/operations",
        "remoteException": {
            "message": "Status(StatusCode=\"PermissionDenied\", Detail=\"No permissions for user\")"
        }
    }
}

gRPC error codes

Mapping for gRPC status codes <-> HTTP status codes is as follow: