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| title | author | description | monikerRange | ms.author | ms.date | uid |
|---|---|---|---|---|---|---|
| gRPC services with ASP.NET Core | juntaoluo | Learn the basic concepts when writing gRPC services with ASP.NET Core. | >= aspnetcore-3.0 | johluo | 03/08/2019 | grpc/aspnetcore |
gRPC services with ASP.NET Core
This document shows how to get started with gRPC services using ASP.NET Core.
Get started with gRPC service in ASP.NET Core
[!INCLUDEView or download sample code]
Visual Studio
See Get started with gRPC services for detailed instructions on how to create a gRPC project.
Visual Studio Code / Visual Studio for Mac
Run dotnet new grpc -o GrpcGreeter from the command line.
Add gRPC services to an ASP.NET Core app
gRPC requires the following packages:
- Grpc.AspNetCore.Server
- Google.Protobuf for protobuf message APIs.
- Grpc.Tools
Configure gRPC
gRPC is enabled with the AddGrpc method:
Each gRPC service is added to the routing pipeline through the MapGrpcService method:
ASP.NET Core middlewares and features share the routing pipeline, therefore an app can be configured to serve additional request handlers. The additional request handlers, such as MVC controllers, work in parallel with the configured gRPC services.
Integration with ASP.NET Core APIs
gRPC services have full access to the ASP.NET Core features such as Dependency Injection (DI) and Logging. For example, the service implementation can resolve a logger service from the DI container via the constructor:
public class GreeterService : Greeter.GreeterBase
{
public GreeterService(ILogger<GreeterService> logger)
{
}
}
By default, the gRPC service implementation can resolve other DI services with any lifetime (Singleton, Scoped, or Transient).
Resolve HttpContext in gRPC methods
The gRPC API provides access to some HTTP/2 message data, such as the method, host, header, and trailers. Access is through the ServerCallContext argument passed to each gRPC method:
ServerCallContext does not provide full access to HttpContext in all ASP.NET APIs. The GetHttpContext extension method provides full access to the HttpContext representing the underlying HTTP/2 message in ASP.NET APIs:
Request body data rate limit
By default, the Kestrel server imposes a minimum request body data rate. For client streaming and duplex streaming calls, this rate may not be satisfied and the connection may be timed out. The minimum request body data rate limit must be disabled when the gRPC service includes client streaming and duplex streaming calls:
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args) =>
Host.CreateDefaultBuilder(args)
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseStartup<Startup>();
webBuilder.ConfigureKestrel((context, options) =>
{
options.Limits.MinRequestBodyDataRate = null;
});
});
}