ServiceModel.Grpc.DesignTime 1.8.2

ServiceModel.Grpc.SelfHost

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.DesignTime is package with C# code generator for client and server-side assets.

Declare a service contract

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);
}

Configure code generator for client proxies

For source code generation create a placeholder - a static partial class, name doesn’t matter. Configure which proxies should be generated via ImportGrpcService attribute.

[ImportGrpcService(typeof(ICalculator))]
internal static partial class MyGrpcServices
{
    // generated code ...
    public static IClientFactory AddCalculatorClient(this IClientFactory clientFactory, Action<ServiceModelGrpcClientOptions> configure = null) {}
}

Instruct ClientFactory to use a proxy from generated code.

IClientFactory clientFactory = new ClientFactory();

// register generated proxy for ICalculator
clientFactory.AddCalculatorClient();

// create an instance
ICalculator calculator = clientFactory.CreateClient<ICalculator>(channel);

Configure code generator for server endpoints

Implement service.

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

    public ValueTask<(int Multiplier, IAsyncEnumerable<int> Values)> MultiplyBy(IAsyncEnumerable<int> values, int multiplier, CancellationToken token)
    {
        ...
    }
}

For source code generation create a placeholder - a static partial class, name doesn’t matter. Configure which endpoints should be generated via ExportGrpcService attribute.

Generate code with extensions for ServiceModel.Grpc.AspNetCore.

[ExportGrpcService(typeof(Calculator), GenerateAspNetExtensions = true)]
internal static partial class MyGrpcServices
{
    // generated code ...
    public static IServiceCollection AddCalculatorOptions(this IServiceCollection services, Action<ServiceModelGrpcServiceOptions<Calculator>> configure) {}

    // generated code ...
    public static GrpcServiceEndpointConventionBuilder MapCalculator(this IEndpointRouteBuilder builder) {}
}

Instruct Grpc.AspNetCore.Server to use a proxy from generated code.

var builder = WebApplication.CreateBuilder();

// optional configuration for Calculator endpoint
builder.Services.AddCalculatorOptions(options => { ... });

var app = builder.Build();

// bind generated Calculator endpoint
app.MapCalculator();

Generate code with extensions for ServiceModel.Grpc.SelfHost.

[ExportGrpcService(typeof(Calculator), GenerateSelfHostExtensions = true)]
internal static partial class MyGrpcServices
{
    // generated code ...
    public static Server.ServiceDefinitionCollection AddCalculator(this Server.ServiceDefinitionCollection services, Func<Calculator> serviceFactory, Action<ServiceModelGrpcServiceOptions> configure = default) {}

    // generated code ...
    public static Server.ServiceDefinitionCollection AddCalculator(this Server.ServiceDefinitionCollection services, Calculator service, Action<ServiceModelGrpcServiceOptions> configure = default) {}
}

Instruct Grpc.Core.Server to use a proxy from generated code.

var server = new Grpc.Core.Server();

// bind generated Calculator endpoint with configuration
server.Services.AddCalculator(
    () => new Calculator(),
    options => { ... });

// or bind generated Calculator endpoint with default configuration
server.Services.AddCalculator(() => new Calculator());

Links

• Documentation
• ServiceModel.Grpc GitHub
• Examples