React to Hosting changes.

test/TestSites/Program.cs

@@ -0,0 +1,20 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using Microsoft.AspNet.Hosting;
+
+namespace TestSites
+{
+    public static class Program
+    {
+        public static void Main(string[] args)
+        {
+            var application = new WebApplicationBuilder()
+                .UseConfiguration(WebApplicationConfiguration.GetDefault(args))
+                .UseStartup("TestSites")
+                .Build();
+
+            application.Run();
+        }
+    }
+}

test/TestSites/Properties/launchSettings.json

@@ -12,13 +12,13 @@
       "commandName": "IISExpress",
       "launchBrowser": true,
       "environmentVariables": {
-        "ASPNET_ENV": "HelloWorld"
+        "ASPNET_ENVIRONMENT": "HelloWorld"
       }
     },
     "web": {
       "commandName": "web",
       "environmentVariables": {
-        "Hosting:Environment": "Development"
+        "ASPNET_ENVIRONMENT": "HelloWorld"
       }
     }
   }

test/TestSites/hosting.json

@@ -0,0 +1,3 @@
+{
+  "server": "Microsoft.AspNet.Server.Kestrel"
+}

test/TestSites/project.json

@@ -20,8 +20,10 @@
     }
   },
   "commands": {
-    "weblistener": "Microsoft.AspNet.Server.WebListener",
+    "web": "TestSites"
-    "web": "Microsoft.AspNet.Server.Kestrel"
+  },
+  "compilationOptions": {
+    "emitEntryPoint": true
   },
   "publishExclude": [
     "node_modules",