Next-Level Application Development: Mastering gRPC in .NET 8

<PackageReference Include="Google.Protobuf" Version="3.23.4" />
<PackageReference Include="Grpc.Net.Client" Version="2.55.0" />
<PackageReference Include="Grpc.Net.Client.Web" Version="2.55.0" />
<PackageReference Include="Grpc.Tools" Version="2.56.0">

//This line specifies the version of the Protocol Buffers language that is used in the file.
syntax = "proto3";

//This line specifies the C# namespace that will be used to generate the code for the messages and services defined in the file.
option csharp_namespace = "HangFire.Protos";

//This line specifies the package name for the messages and services defined in the file.
package HelloWorld;

//This line defines a service called HelloWorld. The service has a single method called SayHello. The SayHello method takes a HelloRequest message as input and returns a HelloReply message as output.
service HelloWorld {
  // Sends a Hello to Server
  rpc SayHello (HelloRequest) returns (HelloReply);
}
//This line defines a message called HelloRequest. The HelloRequest message has a single field called message. The message field is a string that contains the input we will send
//request payload
message HelloRequest {
  string message = 1;
}
//This line defines a message called HelloReply. The HelloReply message has a single field called message. The message field is a string that contains the message that the server sent to the client.
//reponse payload
message HelloReply {
  string message = 1;
}


//The number 1 in the line string message = 1; refers to the field number of the message field. In Protocol Buffers, field numbers are used to uniquely identify fields in messages. The field number 1 is the first field in the HelloRequest/HelloReply message.

   public class HangFireJobManager
  {
      public async Task<bool> ExecuteFireAndForgetJob()
      {
          try
          {
              //serviceEndpoint contains the address of the gRPC server.
              var serviceEndpoint = "https://localhost:7218";

              //The GrpcChannel.ForAddress() method creates a channel to the gRPC server. The GrpcChannelOptions object specifies that the channel will use the GrpcWebHandler to handle HTTP requests.
              var channel = GrpcChannel.ForAddress(serviceEndpoint, new GrpcChannelOptions
              {
                  HttpHandler = new GrpcWebHandler(new HttpClientHandler())
              });
             // The HelloWorld service is a gRPC service that is defined in the HelloWorld.proto file. The HelloWorld.HelloWorldClient class is a class that provides a client for the HelloWorld service.
             var client = new HelloWorld.HelloWorldClient(channel);
              //The helloRequest variable is a HelloRequest message. The Message field of the helloRequest message is set to the string "Calling Server From Client".
              Console.WriteLine("Sending Request to Server");
              var helloRequest = new HelloRequest
              {
                  Message = "Calling Server From Client"
              };
              //The client.SayHello() method sends the helloRequest message to the server and returns a HelloReply message.
              var ServerResponse = await Task.FromResult(client.SayHello(helloRequest));
             // The Serverresponse variable is a HelloReply message.The Message field of the Serverresponse message is set to the greeting that the server sent to the client.
              Console.WriteLine($"Server Reponse :{ServerResponse.Message}");
              return true;

          }
          catch (Exception ex)
          {
              //logging needs to be implemeented
          }
          return true;
      }

  }

//register hangfire service 
builder.Services.AddSingleton<HangFireJobManager>();

//add background job in app builder
var backGroundJobSerivice = app.Services.GetService<IRecurringJobManager>();
backGroundJobSerivice
.AddOrUpdate("MyGrpcJob",() => app.Services.GetService<HangFireJobManager>().ExecuteFireAndForgetJob(),Cron.Daily);

<PackageReference Include="Grpc.AspNetCore" Version="2.55.0" />
 <PackageReference Include="Grpc.AspNetCore.Web" Version="2.55.0" />
<PackageReference Include="Grpc.Tools" Version="2.56.0">

syntax = "proto3";

option csharp_namespace = "GrpcServer.Protos";

package HelloWorld;

// The HelloWorld service definition.
service HelloWorld {
  // Sends a SayHello
  rpc SayHello (HelloRequest) returns (HelloReply);
}

// The request message containing the HelloRequest.
message HelloRequest {
  string message = 1;
}

// The response message containing the HelloReply.
message HelloReply {
  string message = 1;
}

//The HelloWorldService class inherits from the HelloWorld.HelloWorldBase class. The HelloWorld.HelloWorldBase class is a base class that provides the implementation for the SayHello() method in HelloWorld.proto that we have created.
public class HelloWorldService : HelloWorld.HelloWorldBase
{
    public override async Task<HelloReply> SayHello(HelloRequest request, ServerCallContext context)
    {

        HelloReply responseModel = new HelloReply();
        try
        {
            Console.WriteLine($"Request From the Client:{request.Message}");
            responseModel.Message = "Hello From the Server";
            Console.WriteLine("Server Response Sent");
            return responseModel;
        }
        catch (Exception ex)
        {
            //log any error 
            throw;
        }
    }
}

//builder code 

//This line of code registers the Grpc service in the ASP.NET Core application. The Grpc service provides the infrastructure for hosting gRPC services in ASP.NET Core applications.
builder.Services.AddGrpc();

//http request pipeline code 

//This line of code enables gRPC-Web support in the ASP.NET Core application. gRPC-Web is a protocol that allows gRPC services to be accessed over HTTP.
app.UseGrpcWeb(new GrpcWebOptions { DefaultEnabled = true });
//This line of code maps the HelloWorldService class to a gRPC endpoint.
app.MapGrpcService<HelloWorldService>();