Update Kestrel startup sample code with file descriptor for 3.0

[xfoxfu]

Issue description

The sample code provided in AspNetCore.Docs/aspnetcore/fundamentals/servers/kestrel/samples/2.x/KestrelSample/Program.cs fails to start up when FileDescriptor defined on Dotnet Core 3.0 preview.

The command line outputs:

crit: Microsoft.AspNetCore.Server.Kestrel[0]
      Unable to start Kestrel.
System.NotImplementedException: This property is not implemented by this class.
   at System.Net.EndPoint.get_AddressFamily()
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportFactory.BindAsync(EndPoint endpoint, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<>c__DisplayClass21_0`1.<<StartAsync>g__OnBind|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.ListenOptions.BindAsync(AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.EndpointsStrategy.BindAsync(AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)
Unhandled exception. System.NotImplementedException: This property is not implemented by this class.
   at System.Net.EndPoint.get_AddressFamily()
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind()
   at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportFactory.BindAsync(EndPoint endpoint, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.<>c__DisplayClass21_0`1.<<StartAsync>g__OnBind|0>d.MoveNext()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.ListenOptions.BindAsync(AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.EndpointsStrategy.BindAsync(AddressBindContext context)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IServerAddressesFeature addresses, KestrelServerOptions serverOptions, ILogger logger, Func`2 createBinding)
   at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServer.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Hosting.WebHost.StartAsync(CancellationToken cancellationToken)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token)
   at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host)
   at KestrelSample.Program.Main(String[] args) in /AspNetCore.Docs/aspnetcore/fundamentals/servers/kestrel/samples/2.x/KestrelSample/Program.cs:line 74

Software versions

Check the .NET target framework(s) being used, and include the version number(s).

• .NET Core netcoreapp3.0
• .NET Framework
• .NET Standard

If using the .NET Core SDK, include dotnet --info output. If using .NET Framework without the .NET Core SDK, include info from Visual Studio's Help > About Microsoft Visual Studio dialog.

dotnet --info output or About VS info

.NET Core SDK (reflecting any global.json):
 Version:   3.0.100-preview7-012821
 Commit:    6348f1068a

Runtime Environment:
 OS Name:     Mac OS X
 OS Version:  10.14
 OS Platform: Darwin
 RID:         osx.10.14-x64
 Base Path:   /usr/local/share/dotnet/sdk/3.0.100-preview7-012821/

Host (useful for support):
  Version: 3.0.0-preview7-27912-14
  Commit:  4da6ee6450

.NET Core SDKs installed:
  3.0.100-preview7-012821 [/usr/local/share/dotnet/sdk]

.NET Core runtimes installed:
  Microsoft.AspNetCore.App 3.0.0-preview7.19365.7 [/usr/local/share/dotnet/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 3.0.0-preview7-27912-14 [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

To install additional .NET Core runtimes or SDKs:
  https://aka.ms/dotnet-download

[guardrex]

Hello ... We aren't able to provide product support. Your best option is to consult with devs on a support forum, such as Stack Overflow, or a support chat, such as Slack or Gitter. If you think that you found a framework bug, open an issue on the engineering repo.

[Rick-Anderson]

Can you create an issue from the doc page? That will connect the doc to the issue. Go to the bottom of the page and select the Content feedback issue.

[Rick-Anderson]

@guardrex - I asked @coderfox to open an integrated issued from the doc page and ask to update the topic to 3.0. That's a valid doc issue.

[Rick-Anderson]

@guardrex see #13743

[guardrex]

Actually, this more of a @tdykstra thing.

I'll note in passing that AFAIK we have all of the ListenOptions coverage that engineering requested. For any error like that between 2.2 and 3.0, I recommend an engineering issue. If they surface a delta for a given scenario for 3.0 or if they agree that the doc doesn't cover an implementation scenario, then we would normally re-open over here and work it. This isn't actionable here in its current form.

Anywho ---- this is more of a @tdykstra area of the TOC, so I defer to my friend on this one.

[tdykstra]

this is more of a @tdykstra area of the TOC

@guardrex But you have #12842 - Kestrel 3.0 updates, which includes the sample app

[Rick-Anderson]

Closing because it's a duplicate of #12842

[guardrex]

when FileDescriptor defined

@coderfox, you're using custom code that generates that error, correct? ... i.e., this isn't an OOB template app, correct?

[xfoxfu]

@guardrex I can't quite catch up with the meaning of OOB template, but I modified nothing of the sample code except the beginning #define instruction and the target framework.

In your sample code, there are multiple sections of starting the application and bind to a socket, and I am just using the section of binding to existing file descriptors by defining FileDescriptor instead of the default one.

[guardrex]

@coderfox Try the following and see if it runs ...

Project File

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp3.0</TargetFramework>
  </PropertyGroup>
  
</Project>

Program.cs

using System;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;

namespace KestrelSample
{
    public class Program
    {
        public static void Main(string[] args)
        {
            CreateHostBuilder(args).Build().Run();
        }

        public static IHostBuilder CreateHostBuilder(string[] args) =>
            Host.CreateDefaultBuilder(args)
                .ConfigureWebHostDefaults(webBuilder =>
                {
                    webBuilder.ConfigureKestrel(serverOptions =>
                    {
                        var fds = Environment
                            .GetEnvironmentVariable("SD_LISTEN_FDS_START");
                        var fd = ulong.Parse(fds);

                        serverOptions.ListenHandle(fd);
                        serverOptions.ListenHandle(fd, listenOptions =>
                        {
                            listenOptions.UseHttps("testCert.pfx", "testpassword");
                        });
                    })
                    .UseStartup<Startup>();
                });
    }
}

[xfoxfu]

@guardrex No. Exactly the same exception is thrown.

[guardrex]

MOVED TO #12842 (comment)