ServiceModel.Grpc.AspNetCore 1.8.3

ServiceModel.Grpc.AspNetCore

ServiceModel.Grpc enables applications to communicate with gRPC services using a code-first approach (no .proto files), helps to get around limitations of gRPC protocol like "only reference types", "exact one input", "no nulls", "no value-types". Provides exception handling. Helps to migrate existing WCF solution to gRPC with minimum effort.

ServiceModel.Grpc.AspNetCore is package with code-first extensions for Grpc.AspNetCore.Server.

Declare a service contract and implement service

A service contract is an interface decorated with the ServiceContract attribute. Interface methods decorated with the OperationContract attribute are treated as gRPC operations.

For example, following ICalculator contract with unary Sum operation and client streaming MultiplyBy operation:

[ServiceContract]
public interface ICalculator
{
    [OperationContract]
    Task<long> Sum(long x, int y, int z, CancellationToken token = default);

    [OperationContract]
    ValueTask<(int Multiplier, IAsyncEnumerable<int> Values)> MultiplyBy(IAsyncEnumerable<int> values, int multiplier, CancellationToken token = default);
}

internal sealed class Calculator : ICalculator
{
    public Task<long> Sum(long x, int y, int z, CancellationToken token) => x + y + z;

    public ValueTask<(int Multiplier, IAsyncEnumerable<int> Values)> MultiplyBy(IAsyncEnumerable<int> values, int multiplier, CancellationToken token)
    {
        var multiplicationResult = DoMultiplication(values, multiplier, token);
        return new ValueTask<(int, IAsyncEnumerable<int>)>((multiplier, multiplicationResult));
    }

    private static async IAsyncEnumerable<int> DoMultiplication(IAsyncEnumerable<int> values, int multiplier, [EnumeratorCancellation] CancellationToken token)
    {
        await foreach (var value in values.WithCancellation(token))
        {
            yield return value * multiplier;
        }
    }
}

Configure service

Enable ServiceModel.Grpc code-first and add service to the routing pipeline.

var builder = WebApplication.CreateBuilder();

// optional Grpc.AspNetCore.Server configuration
builder.Services.AddGrpc(options =>
{
    // ...
});

// enable ServiceModel.Grpc code-first
builder.Services.AddServiceModelGrpc(options =>
{
    options.DefaultMarshallerFactory = ...
    options.DefaultErrorHandlerFactory = ...
    options.Filters = ...
});

var app = builder.Build();

// bind the service
app.MapGrpcService<Calculator>();

app.Run();

Links

• Documentation
• ServiceModel.Grpc GitHub
• Examples