Store Dotnet Core Grpc Server as a Console Application?

Question

I am trying to save the Grpc server as a console daemon. This gRPC server is a microservice that runs in a docker container.

All the examples I can find use the following:

Console.ReadKey();

This really blocks the main thread and continues to work, but does not work in docker with the following error:

"Cannot read keys when either application does not have a console or when console input has been redirected. Try Console.Read."

Now, I could probably try to find a workaround for dockers, but this is still not the case. Does anyone know of a good “finished production” to support the job?

Answer 1

ManualResetEvent, , .

, :

class Program
{
  public static ManualResetEvent Shutdown = new ManualResetEvent(false);

  static void Main(string[] args)
  {
    Task.Run(() =>
    {
      Console.WriteLine("Waiting in other thread...");
      Thread.Sleep(2000);
      Shutdown.Set();
    });

    Console.WriteLine("Waiting for signal");
    Shutdown.WaitOne();

    Console.WriteLine("Resolved");
  }
}

, - :

using System;
using System.Net.Sockets;
using System.Threading;
using System.Threading.Tasks;
using Grpc.Core;
using Helloworld;

namespace GreeterServer
{
  class GreeterImpl : Greeter.GreeterBase
  {
    // Server side handler of the SayHello RPC
    public override Task<HelloReply> SayHello(HelloRequest request, ServerCallContext context)
    {
      Program.Shutdown.Set(); // <--- Signals the main thread to continue 
      return Task.FromResult(new HelloReply {Message = "Hello " + request.Name});
    }
  }

  class Program
  {
    const int Port = 50051;

    public static ManualResetEvent Shutdown = new ManualResetEvent(false);

    public static void Main(string[] args)
    {
      Server server = new Server
      {
        Services = {Greeter.BindService(new GreeterImpl())},
        Ports = {new ServerPort("localhost", Port, ServerCredentials.Insecure)}
      };
      server.Start();

      Shutdown.WaitOne(); // <--- Waits for ever or signal received

      server.ShutdownAsync().Wait();
    }
  }
}

Answer 2

Microsoft.Extensions.Hosting pacakge, asp.net .

​​asp.net, API HostBuilder, gRPC- . - , (, Control-C):

using System;
using System.Threading.Tasks;
using Microsoft.Extensions.Hosting;

public class Program
{
    public static async Task Main(string[] args)
    {
        var hostBuilder = new HostBuilder();

         // register your configuration and services.
        ....

        await hostBuilder.RunConsoleAsync();
    }
}

gRPC, / Grpc.Core.Server . - - , , , , , . IHostedService. , GrpcHostedService :

using System.Threading;
using System.Threading.Tasks;
using Grpc.Core;
using Microsoft.Extensions.Hosting;

namespace Grpc.Host
{
    public class GrpcHostedService: IHostedService
    {
        private Server _server;

        public GrpcHostedService(Server server)
        {
            _server = server;
        }

        public Task StartAsync(CancellationToken cancellationToken)
        {
            _server.Start();
            return Task.CompletedTask;
        }

        public async Task StopAsync(CancellationToken cancellationToken) => await _server.ShutdownAsync();
    }
}

. GrpcHostedService, , StartAsync , . , StopAsync, , Grpc.

Program.cs :

public class Program
{
    public static async Task Main(string[] args)
    {
        var hostBuilder = new HostBuilder()
             // Add configuration, logging, ...
            .ConfigureServices((hostContext, services) =>
            {
                // Better to use Dependency Injection for GreeterImpl
                Server server = new Server
                {
                    Services = {Greeter.BindService(new GreeterImpl())},
                    Ports = {new ServerPort("localhost", 5000, ServerCredentials.Insecure)}
                };
                services.AddSingleton<Server>(server);
                services.AddSingleton<IHostedService, GrpcHostedService>();
            });

        await hostBuilder.RunConsoleAsync();
    }
}

, StartAsync , , , StartAsync Server, , gRPC.

Control-C, StopAsync , StopAsync Server, .

HostBuilder .