.Net Core で Linux デーモンを作成する方法

Linux で実行されている .NET Core デーモンを適切に強制終了することと、別の非同期メソッドの代わりにイベントを待機することは可能ですか?

using System;
using System.Runtime.Loader;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    public class Program
    {
        private static TaskCompletionSource<object> taskToWait;

        public static void Main(string[] args)
        {
            taskToWait = new TaskCompletionSource<object>();

            AssemblyLoadContext.Default.Unloading += SigTermEventHandler;
            Console.CancelKeyPress += new ConsoleCancelEventHandler(CancelHandler);

            //eventSource.Subscribe(eventSink) or something...

            taskToWait.Task.Wait();

            AssemblyLoadContext.Default.Unloading -= SigTermEventHandler;
            Console.CancelKeyPress -= new ConsoleCancelEventHandler(CancelHandler);

        }


        private static void SigTermEventHandler(AssemblyLoadContext obj)
        {
            System.Console.WriteLine("Unloading...");
            taskToWait.TrySetResult(null);
        }

        private static void CancelHandler(object sender, ConsoleCancelEventArgs e)
        {
            System.Console.WriteLine("Exiting...");
            taskToWait.TrySetResult(null);
        }

    }
}

.net コア Web ホストがコンソール アプリケーションでシャットダウンを待機する方法に似たアイデアをいじりました。私は GitHub でそれをレビューしていて、Run をどのように実行したかの要点を抽出することができました

https://github.com/aspnet/Hosting/blob/15008b0b7fcb54235a9de3ab844c066aaf42ea44/src/Microsoft.AspNetCore.Hosting/WebHostExtensions.cs#L86

public static class ConsoleHost {
    /// <summary>
    /// Block the calling thread until shutdown is triggered via Ctrl+C or SIGTERM.
    /// </summary>
    public static void WaitForShutdown() {
        WaitForShutdownAsync().GetAwaiter().GetResult();
    }


    /// <summary>
    /// Runs an application and block the calling thread until host shutdown.
    /// </summary>
    /// <param name="host">The <see cref="IWebHost"/> to run.</param>
    public static void Wait() {
        WaitAsync().GetAwaiter().GetResult();
    }

    /// <summary>
    /// Runs an application and returns a Task that only completes when the token is triggered or shutdown is triggered.
    /// </summary>
    /// <param name="host">The <see cref="IConsoleHost"/> to run.</param>
    /// <param name="token">The token to trigger shutdown.</param>
    public static async Task WaitAsync(CancellationToken token = default(CancellationToken)) {
        //Wait for the token shutdown if it can be cancelled
        if (token.CanBeCanceled) {
            await WaitAsync(token, shutdownMessage: null);
            return;
        }
        //If token cannot be cancelled, attach Ctrl+C and SIGTERN shutdown
        var done = new ManualResetEventSlim(false);
        using (var cts = new CancellationTokenSource()) {
            AttachCtrlcSigtermShutdown(cts, done, shutdownMessage: "Application is shutting down...");
            await WaitAsync(cts.Token, "Application running. Press Ctrl+C to shut down.");
            done.Set();
        }
    }

    /// <summary>
    /// Returns a Task that completes when shutdown is triggered via the given token, Ctrl+C or SIGTERM.
    /// </summary>
    /// <param name="token">The token to trigger shutdown.</param>
    public static async Task WaitForShutdownAsync(CancellationToken token = default (CancellationToken)) {
        var done = new ManualResetEventSlim(false);
        using (var cts = CancellationTokenSource.CreateLinkedTokenSource(token)) {
            AttachCtrlcSigtermShutdown(cts, done, shutdownMessage: string.Empty);
            await WaitForTokenShutdownAsync(cts.Token);
            done.Set();
        }
    }

    private static async Task WaitAsync(CancellationToken token, string shutdownMessage) {
        if (!string.IsNullOrEmpty(shutdownMessage)) {
            Console.WriteLine(shutdownMessage);
        }
        await WaitForTokenShutdownAsync(token);
    }


    private static void AttachCtrlcSigtermShutdown(CancellationTokenSource cts, ManualResetEventSlim resetEvent, string shutdownMessage) {
        Action ShutDown = () => {
            if (!cts.IsCancellationRequested) {
                if (!string.IsNullOrWhiteSpace(shutdownMessage)) {
                    Console.WriteLine(shutdownMessage);
                }
                try {
                    cts.Cancel();
                } catch (ObjectDisposedException) { }
            }
            //Wait on the given reset event
            resetEvent.Wait();
        };

        AppDomain.CurrentDomain.ProcessExit += delegate { ShutDown(); };
        Console.CancelKeyPress += (sender, eventArgs) => {
            ShutDown();
            //Don't terminate the process immediately, wait for the Main thread to exit gracefully.
            eventArgs.Cancel = true;
        };
    }

    private static async Task WaitForTokenShutdownAsync(CancellationToken token) {
        var waitForStop = new TaskCompletionSource<object>();
        token.Register(obj => {
            var tcs = (TaskCompletionSource<object>)obj;
            tcs.TrySetResult(null);
        }, waitForStop);
        await waitForStop.Task;
    }
}

IConsoleHost のようなものを適応させてみました しかし、私がそれを過剰に設計していることにすぐに気付きました。主要部分を await ConsoleUtil.WaitForShutdownAsync(); のようなものに抽出しました Console.ReadLine のように動作する

これにより、ユーティリティを次のように使用できるようになりました

public class Program {

    public static async Task Main(string[] args) {
        //relevant code goes here
        //...

        //wait for application shutdown
        await ConsoleUtil.WaitForShutdownAsync();
    }
}

そこから systemd を作成します 次のリンクのように、残りの部分は取得できます

C# で Linux デーモンを作成する