ApplicationShutdownExtensionMethods.cs

using System;
using System.Threading.Tasks;
using Microsoft.Framework.Runtime;
using Mono.Unix;

namespace Example
{
    public static class ApplicationShutdownExtensionMethods
    {
        public static void OnCancelKeyPress(this IApplicationShutdown applicationShutdown)
        {
            Console.WriteLine("To terminate, press CTRL+C");
            Console.CancelKeyPress += delegate
            {
                applicationShutdown.RequestShutdown();
                Console.WriteLine("Received cancel key press");
            };
        }

        public static void OnUnixSignals(this IApplicationShutdown applicationShutdown)
        {
            Task.Factory.StartNew(() =>
            {
                var sigInt = new UnixSignal(Mono.Unix.Native.Signum.SIGINT);
                var sigTerm = new UnixSignal(Mono.Unix.Native.Signum.SIGTERM);
                Console.WriteLine("To terminate, send SIGINT or SIGTERM to the process");
                UnixSignal.WaitAny(new[] { sigInt, sigTerm });
                Console.WriteLine("Received signal");
                applicationShutdown.RequestShutdown();
            }, TaskCreationOptions.LongRunning);
        }
    }
}

Example.service

[Unit]
Description=Example

[Service]
WorkingDirectory=/path/to/kestrel/script
User=someone
ExecStart=/bin/bash kestrel
Environment=TEMP=/tmp
Type=notify
NotifyAccess=main

[Install]
WantedBy=multi-user.target

Startup.cs

public void Configure(IApplicationShutdown applicationShutdown)
{
    applicationShutdown.OnCancelKeyPress();
    applicationShutdown.OnUnixSignals();
    SystemdNotification.Do(); // Stay tuned for a new PR in Hosting
}

SystemdNotification.cs

using System.Runtime.InteropServices;
using Microsoft.AspNet.Hosting;
using Microsoft.Framework.Runtime;

namespace Example
{
    public static class SystemdNotification
    {
        public static void Do()
        {
            sd_notify(0, "READY=1");
        }
        
        [DllImport("libsystemd.so.0")]
        private static extern int sd_notify(int unset_environment, string state);
    }
}