Fix StandBy mode bug

Author: mathewc

src/WebJobs.Script.WebHost/App_Start/WebHostResolver.cs

@@ -124,29 +124,17 @@ private void EnsureInitialized(WebHostSettings settings)
             {
                 if (_standbyHostManager == null)
                 {
-                    _standbyScriptHostConfig = CreateStandbyScriptHostConfiguration(settings);
-                    StandbyManager.Initialize(_standbyScriptHostConfig);
+                    _standbyScriptHostConfig = CreateScriptHostConfiguration(settings, true);
                     _standbyHostManager = new WebScriptHostManager(_standbyScriptHostConfig, _secretManagerFactory, _eventManager, _settingsManager, settings);
                     _standbyReceiverManager = new WebHookReceiverManager(_standbyHostManager.SecretManager);
+
                     InitializeFileSystem();
+                    StandbyManager.Initialize(_standbyScriptHostConfig);
                 }
             }
         }
 
-        internal static ScriptHostConfiguration CreateStandbyScriptHostConfiguration(WebHostSettings settings)
-        {
-            settings.ScriptPath = Path.Combine(Path.GetTempPath(), "Functions", "Standby");
-
-            var scriptHostConfig = CreateScriptHostConfiguration(settings);
-
-            scriptHostConfig.FileLoggingMode = FileLoggingMode.Always;
-            scriptHostConfig.HostConfig.StorageConnectionString = null;
-            scriptHostConfig.HostConfig.DashboardConnectionString = null;
-
-            return scriptHostConfig;
-        }
-
-        internal static ScriptHostConfiguration CreateScriptHostConfiguration(WebHostSettings settings)
+        internal static ScriptHostConfiguration CreateScriptHostConfiguration(WebHostSettings settings, bool inStandbyMode = false)
         {
             var scriptHostConfig = new ScriptHostConfiguration
             {
@@ -158,6 +146,14 @@ internal static ScriptHostConfiguration CreateScriptHostConfiguration(WebHostSet
                 LoggerFactoryBuilder = settings.LoggerFactoryBuilder
             };
 
+            if (inStandbyMode)
+            {
+                scriptHostConfig.RootScriptPath = Path.Combine(Path.GetTempPath(), "Functions", "Standby");
+                scriptHostConfig.FileLoggingMode = FileLoggingMode.DebugOnly;
+                scriptHostConfig.HostConfig.StorageConnectionString = null;
+                scriptHostConfig.HostConfig.DashboardConnectionString = null;
+            }
+
             scriptHostConfig.HostConfig.HostId = Utility.GetDefaultHostId(_settingsManager, scriptHostConfig);
 
             return scriptHostConfig;

test/WebJobs.Script.Tests.Integration/Host/StandbyManagerTests.cs

@@ -116,10 +116,8 @@ public async Task StandbyMode_EndToEnd()
 
                 await Task.Delay(2000);
 
-                // verify host logs
-                string hostLogDirectory = Path.Combine(webHostSettings.LogPath, "Host");
-                string hostLogFilePath = Directory.EnumerateFiles(hostLogDirectory).First();
-                string[] logLines = File.ReadAllLines(hostLogFilePath);
+                // verify logs
+                string[] logLines = traceWriter.Traces.Select(p => p.Message).ToArray();
                 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")));

test/WebJobs.Script.Tests/WebHostResolverTests.cs

@@ -44,13 +44,16 @@ public void GetScriptHostConfiguration_SetsHostId()
         }
 
         [Fact]
-        public void CreateStandbyScriptHostConfiguration_StandbyMode_ReturnsExpectedConfiguration()
+        public void CreateScriptHostConfiguration_StandbyMode_ReturnsExpectedConfiguration()
         {
-            var settings = new WebHostSettings();
+            var settings = new WebHostSettings
+            {
+                IsSelfHost = true
+            };
 
-            var config = WebHostResolver.CreateStandbyScriptHostConfiguration(settings);
+            var config = WebHostResolver.CreateScriptHostConfiguration(settings, true);
 
-            Assert.Equal(FileLoggingMode.Always, config.FileLoggingMode);
+            Assert.Equal(FileLoggingMode.DebugOnly, config.FileLoggingMode);
             Assert.Null(config.HostConfig.StorageConnectionString);
             Assert.Null(config.HostConfig.DashboardConnectionString);
             Assert.Equal(Path.Combine(Path.GetTempPath(), "Functions", "Standby"), config.RootScriptPath);