How to restart asp.net core app programmatically?

Before you read my answer: This solution is going to stop the app and cause the application to re-enter the startup in the next request.

.NET Core 2 There may come a time when you wish to force your ASP.Net Core 2 site to recycle programmatically. Even in MVC/WebForms days this wasn't necessarily a recommended practice but alas, there is a way. ASP.Net Core 2 allows for the injection of an IApplicationLifetime object that will let you do a few handy things. First, it will let you register events for Startup, Shutting Down and Shutdown similar to what might have been available via a Global.asax back in the day. But, it also exposes a method to allow you to shutdown the site (without a hack!). You'll need to inject this into your site, then simply call it. Below is an example of a controller with a route that will shutdown a site.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Mvc;

namespace MySite.Controllers
{
    public class WebServicesController : Controller
    {
        private IApplicationLifetime ApplicationLifetime { get; set; }

        public WebServicesController(IApplicationLifetime appLifetime)
        {
            ApplicationLifetime = appLifetime;
        }

        public async Task ShutdownSite()
        {
            ApplicationLifetime.StopApplication();
            return "Done";
        }

    }
}

Source: http://www.blakepell.com/asp-net-core-ability-to-restart-your-site-programatically-updated-for-2-0

ASP.NET Core 3+

Since the accepted answer is using IApplicationLifetime which became obsolete in ASP.NET Core 3 onwards, the new recommended way is to use IHostApplicationLifetime which is located in the Microsoft.Extensions.Hosting namespace.

In my Blazor application, I can use following code:

@inject IHostApplicationLifetime AppLifetime

<button @onclick="() => AppLifetime.StopApplication()">Restart</button>

For .NET Core 2.2 you can use following code:

using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Hosting;
using System.Threading;

namespace BuildMonitor
{
    public class Program
    {
        private static CancellationTokenSource cancelTokenSource = new System.Threading.CancellationTokenSource();

        public static void Main(string[] args)
        {
            var host = CreateWebHostBuilder(args).Build();
            host.RunAsync(cancelTokenSource.Token).GetAwaiter().GetResult();
        }

        public static IWebHostBuilder CreateWebHostBuilder(string[] args) =>
            WebHost.CreateDefaultBuilder(args)
                .UseStartup<Startup>();

        public static void Shutdown()
        {
            cancelTokenSource.Cancel();
        }
    }
}

And server shutdown could be placed for example behind some web page:

using System;
using Microsoft.AspNetCore.Mvc.RazorPages;

namespace BuildMonitor.Pages
{
    public class StopServerModel : PageModel
    {
        public void OnGet()
        {
            Console.WriteLine("Forcing server shutdown.");
            Program.Shutdown();
        }
    }
}

stopServer.bat could be for example like this:

@echo off
rem curl http://localhost:5000/StopServer >nul 2>&1
powershell.exe -Command (new-object System.Net.WebClient).DownloadString('http://localhost:5000/StopServer') >nul
exit /b 0

None of the solutions above did what I wanted. So that is what I came up with:

 public class Program
{
    private static CancellationTokenSource cts = new CancellationTokenSource();
    private static string[] _args;
    private static bool _restartRequest;

    public static async Task Main(string[] args)
    {
        _args = args;

        await StartServer();
        while (_restartRequest)
        {
            _restartRequest = false;
            Console.WriteLine("Restarting App");
            await StartServer();
        }
    }

    public static void Restart()
    {
        _restartRequest = true;
        cts.Cancel();
    }

    private static async Task StartServer()
    {
        try
        {
            cts = new CancellationTokenSource();
            await CreateHostBuilder(_args).RunConsoleAsync(cts.Token);
        }
        catch (OperationCanceledException e)
        {
            Console.WriteLine(e);
        }
    }

    public static IHostBuilder CreateHostBuilder(string[] args) =>
        Host.CreateDefaultBuilder(args)
            .ConfigureWebHostDefaults(webBuilder =>
            {
                webBuilder.UseStartup<Startup>();
            });
}