React to WebListener configuration changes.

src/MusicStore/Program.cs

@@ -1,4 +1,5 @@
 using Microsoft.AspNetCore.Hosting;
+using Microsoft.Net.Http.Server;
 
 namespace MusicStore
 {
@@ -6,14 +7,27 @@ namespace MusicStore
     {
         public static void Main(string[] args)
         {
-            var host = new WebHostBuilder()
+            var builder = new WebHostBuilder()
                 // We set the server by name before default args so that command line arguments can override it.
                 // This is used to allow deployers to choose the server for testing.
                 .UseServer("Microsoft.AspNetCore.Server.Kestrel")
                 .UseDefaultHostingConfiguration(args)
                 .UseIISIntegration()
-                .UseStartup("MusicStore")
-                .Build();
+                .UseStartup("MusicStore");
+
+            if (string.Equals(builder.GetSetting("server"), "Microsoft.AspNetCore.Server.WebListener", System.StringComparison.Ordinal)
+                && string.Equals(builder.GetSetting("environment"), "NtlmAuthentication", System.StringComparison.Ordinal))
+            {
+                // Set up NTLM authentication for WebListener like below.
+                // For IIS and IISExpress: Use inetmgr to setup NTLM authentication on the application vDir or
+                // modify the applicationHost.config to enable NTLM.
+                builder.UseWebListener(options =>
+                {
+                    options.Listener.AuthenticationManager.AuthenticationSchemes = AuthenticationSchemes.NTLM;
+                });
+            }
+
+            var host = builder.Build();
 
             host.Run();
         }

src/MusicStore/StartupNtlmAuthentication.cs

@@ -102,16 +102,6 @@ namespace MusicStore
             // request pipeline.
             // Note: Not recommended for production.
             app.UseDeveloperExceptionPage();
-
-            // Set up NTLM authentication for WebListener like below.
-            // For IIS and IISExpress: Use inetmgr to setup NTLM authentication on the application vDir or
-            // modify the applicationHost.config to enable NTLM.
-            var listener = app.ServerFeatures.Get<WebListener>();
-            if (listener != null)
-            {
-                listener.AuthenticationManager.AuthenticationSchemes = AuthenticationSchemes.NTLM;
-            }
-
             app.UseDatabaseErrorPage();
 
             // Add the runtime information page that can be used by developers