Host specialization improvements

Author: mathewc

src/WebJobs.Script.WebHost/Properties/Resources.Designer.cs

@@ -256,7 +256,7 @@
 }</value>
   </data>
   <data name="HostSpecializationTrace" xml:space="preserve">
-    <value>Host has been specialized</value>
+    <value>Starting host specialization</value>
   </data>
   <data name="TraceAddOrUpdateFunctionSecret" xml:space="preserve">
     <value>{0} secret '{1}' for '{2}' {3}.</value>

src/WebJobs.Script.WebHost/Properties/Resources.resx

@@ -122,9 +122,14 @@ internal void EnsureInitialized(WebHostSettings settings)
 
                     if (_standbyHostManager != null)
                     {
-                        // we're undergoing the one and only one
+                        // we're starting the one and only one
                         // standby mode specialization
                         _activeScriptHostConfig.TraceWriter.Info(Resources.HostSpecializationTrace);
+
+                        // After specialization, we need to ensure that custom timezone
+                        // settings configured by the user (WEBSITE_TIME_ZONE) are honored.
+                        // DateTime caches timezone information, so we need to clear the cache.
+                        TimeZoneInfo.ClearCachedData();
                     }
 
                     _standbyHostManager?.Dispose();

src/WebJobs.Script.WebHost/WebHostResolver.cs

@@ -84,6 +84,7 @@ public async Task StandbyMode_EndToEnd()
                     IsSelfHost = true,
                     LogPath = Path.Combine(testRootPath, "Logs"),
                     SecretsPath = Path.Combine(testRootPath, "Secrets"),
+                    ScriptPath = testRootPath,
                     TraceWriter = traceWriter
                 };
 
@@ -111,6 +112,12 @@ public async Task StandbyMode_EndToEnd()
                 responseBody = await response.Content.ReadAsStringAsync();
                 Assert.Equal("WarmUp complete.", responseBody);
 
+                // Now specialize the host
+                ScriptSettingsManager.Instance.SetSetting(EnvironmentSettingNames.AzureWebsitePlaceholderMode, "0");
+                request = new HttpRequestMessage(HttpMethod.Get, "api/dne");
+                response = await httpClient.SendAsync(request);
+                Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
+
                 httpServer.Dispose();
                 httpClient.Dispose();
 
@@ -121,6 +128,7 @@ public async Task StandbyMode_EndToEnd()
                 Assert.Equal(2, logLines.Count(p => p.Contains("Host is in standby mode")));
                 Assert.Equal(1, logLines.Count(p => p.Contains("Stopping Host")));
                 Assert.Equal(2, logLines.Count(p => p.Contains("Executed 'Functions.WarmUp' (Succeeded")));
+                Assert.Equal(1, logLines.Count(p => p.Contains("Starting host specialization")));
             }
         }
     }