Introduction to gRPC using C#

In gRPC, a client application can directly call a method on a server application on a different machine as if it were a local object, making it easier to create distributed applications and services. gRPC uses HTTP/2 as its underlying transport protocol and is based around the idea of defining a service, specifying the methods that can be called remotely with their parameters and return types. On the server side, the server implements this interface and runs a gRPC server to handle client calls. On the client side, the client has a stub (or referred to as just 'client') that provides the same methods as the server.

This project

Contains two applications -

• Server - A gRPC server application that demonstrates the below types of RPCs -

  • Unary RPC
  • Server streaming RPC
  • Client streaming RPC
  • Bidirectional RPC

• Client - A client console application to call any of the RPC endpoints on the server.

Protocol Buffers and .NET tooling

gRPC uses Protocol Buffers for serializing structured data, a contract-first approach to API development. Services and messages are defined in *.proto files.

You can use the protocol buffer compiler called protoc to generate data access classes as well as client and server code in your preferred language. protoc supports many programming languages including C# (Supported languages). But dotnet comes with all the necessary tooling that makes it even easier to generate C# code.

.NET types for services, clients, and messages are automatically generated by including *.proto files in a project.

• Add a package reference to Grpc.Tools

• Add *.proto files to the <Protobuf> item group in the *.csproj file. For example to generate client code, in client's .csproj file -

  <ItemGroup>
      <Protobuf Include="Protos\grpc-demo.proto" GrpcServices="Client" />
  </ItemGroup>
  

  To generate server code, in server's .csproj file -

  <ItemGroup>
      <Protobuf Include="Protos\grpc-demo.proto" GrpcServices="Server" />
  </ItemGroup>
  

gRPC services can be hosted on ASP.NET Core. Services have full integration with ASP.NET Core features such as logging, dependency injection (DI), authentication, and authorization.

How to run it?

This project requires dotnet to be installed in order to run it. Run the server in a terminal window -

dotnet run --project ./server

Run the client in another terminal window -

dotnet run --project ./client

References

• Introduction to HTTP/2
• Introduction to gRPC
• Core concepts, architecture and lifecycle
• Introduction to gRPC on .NET