Handle SIGTERMs for graceful shutdown (#876)

src/Microsoft.AspNetCore.Hosting/Internal/WebHost.cs

@@ -176,7 +176,7 @@ namespace Microsoft.AspNetCore.Hosting.Internal
                 var model = new ErrorPageModel();
                 var runtimeType = Microsoft.Extensions.Internal.RuntimeEnvironment.RuntimeType;
                 model.RuntimeDisplayName = (runtimeType == "CoreCLR") ? ".NET Core" : runtimeType == "CLR" ? ".NET Framework" : "Mono";
-#if NETSTANDARD1_3
+#if NETSTANDARD1_3 || NETSTANDARD1_5
                 var systemRuntimeAssembly = typeof(System.ComponentModel.DefaultValueAttribute).GetTypeInfo().Assembly;
                 var assemblyVersion = new AssemblyName(systemRuntimeAssembly.FullName).Version.ToString();
                 var clrVersion = assemblyVersion;

src/Microsoft.AspNetCore.Hosting/WebHostExtensions.cs

@@ -2,6 +2,10 @@
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
+#if NETSTANDARD1_5
+using System.Reflection;
+using System.Runtime.Loader;
+#endif
 using System.Threading;
 using Microsoft.AspNetCore.Hosting.Server.Features;
 using Microsoft.Extensions.DependencyInjection;
@@ -16,18 +20,33 @@ namespace Microsoft.AspNetCore.Hosting
         /// <param name="host">The <see cref="IWebHost"/> to run.</param>
         public static void Run(this IWebHost host)
         {
+            var done = new ManualResetEventSlim(false);
             using (var cts = new CancellationTokenSource())
             {
+                Action shutdown = () =>
+                {
+                    if (!cts.IsCancellationRequested)
+                    {
+                        Console.WriteLine("Application is shutting down...");
+                        cts.Cancel();
+                    }
+
+                    done.Wait();
+                };
+
+#if NETSTANDARD1_5
+                var assemblyLoadContext = AssemblyLoadContext.GetLoadContext(typeof(WebHostExtensions).GetTypeInfo().Assembly);
+                assemblyLoadContext.Unloading += context => shutdown();
+#endif
                 Console.CancelKeyPress += (sender, eventArgs) =>
                 {
-                    Console.WriteLine("Application is shutting down...");
+                    shutdown();
-                    cts.Cancel();
-
                     // Don't terminate the process immediately, wait for the Main thread to exit gracefully.
                     eventArgs.Cancel = true;
                 };
 
                 host.Run(cts.Token, "Application started. Press Ctrl+C to shut down.");
+                done.Set();
             }
         }
 

src/Microsoft.AspNetCore.Hosting/project.json

@@ -69,6 +69,12 @@
       "dependencies": {
         "System.Diagnostics.StackTrace": "4.3.0-*"
       }
+    },
+    "netstandard1.5": {
+      "dependencies": {
+        "System.Diagnostics.StackTrace": "4.3.0-*",
+        "System.Runtime.Loader": "4.3.0-*"
+      }
     }
   },
   "tools": {