Isolation for placeholder mode files

Author: mathewc

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

@@ -114,9 +114,11 @@ internal void EnsureInitialized(WebHostSettings settings)
             if (!WebScriptHostManager.InStandbyMode)
             {
                 // standby mode can only change from true to false
-                // When standby mode changes, we reset all instances
+                // when standby mode changes, we reset all instances
                 if (_activeHostManager == null)
                 {
+                    _settingsManager.Reset();
+
                     _activeScriptHostConfig = CreateScriptHostConfiguration(settings);
                     _activeHostManager = new WebScriptHostManager(_activeScriptHostConfig, _secretManagerFactory, _eventManager, _settingsManager, settings);
                     _activeReceiverManager = new WebHookReceiverManager(_activeHostManager.SecretManager);
@@ -139,15 +141,15 @@ internal void EnsureInitialized(WebHostSettings settings)
                     _standbyScriptHostConfig = null;
                     _standbyHostManager = null;
                     _standbyReceiverManager = null;
-                    _settingsManager.Reset();
                 }
             }
             else
             {
                 if (_standbyHostManager == null)
                 {
-                    _standbyScriptHostConfig = CreateScriptHostConfiguration(settings, true);
-                    _standbyHostManager = new WebScriptHostManager(_standbyScriptHostConfig, _secretManagerFactory, _eventManager, _settingsManager, settings);
+                    var standbySetings = CreateStandbySettings(settings);
+                    _standbyScriptHostConfig = CreateScriptHostConfiguration(standbySetings, true);
+                    _standbyHostManager = new WebScriptHostManager(_standbyScriptHostConfig, _secretManagerFactory, _eventManager, _settingsManager, standbySetings);
                     _standbyReceiverManager = new WebHookReceiverManager(_standbyHostManager.SecretManager);
 
                     InitializeFileSystem();
@@ -156,6 +158,26 @@ internal void EnsureInitialized(WebHostSettings settings)
             }
         }
 
+        internal static WebHostSettings CreateStandbySettings(WebHostSettings settings)
+        {
+            // we need to create a new copy of the settings to avoid modifying
+            // the global settings
+            // important that we use paths that are different than the configured paths
+            // to ensure that placeholder files are isolated
+            string tempRoot = Path.GetTempPath();
+            var standbySettings = new WebHostSettings
+            {
+                LogPath = Path.Combine(tempRoot, @"Functions\Standby\Logs"),
+                ScriptPath = Path.Combine(tempRoot, @"Functions\Standby\WWWRoot"),
+                SecretsPath = Path.Combine(tempRoot, @"Functions\Standby\Secrets"),
+                LoggerFactoryBuilder = settings.LoggerFactoryBuilder,
+                TraceWriter = settings.TraceWriter,
+                IsSelfHost = settings.IsSelfHost
+            };
+
+            return standbySettings;
+        }
+
         internal static ScriptHostConfiguration CreateScriptHostConfiguration(WebHostSettings settings, bool inStandbyMode = false)
         {
             var scriptHostConfig = new ScriptHostConfiguration
@@ -170,7 +192,6 @@ internal static ScriptHostConfiguration CreateScriptHostConfiguration(WebHostSet
 
             if (inStandbyMode)
             {
-                scriptHostConfig.RootScriptPath = Path.Combine(Path.GetTempPath(), "Functions", "Standby");
                 scriptHostConfig.FileLoggingMode = FileLoggingMode.DebugOnly;
                 scriptHostConfig.HostConfig.StorageConnectionString = null;
                 scriptHostConfig.HostConfig.DashboardConnectionString = null;

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

@@ -25,6 +25,7 @@ public StandbyManagerTests()
         {
             _settingsManager = ScriptSettingsManager.Instance;
             _traceWriter = new TestTraceWriter(TraceLevel.Info);
+            WebScriptHostManager.ResetStandbyMode();
         }
 
         [Fact]
@@ -81,7 +82,7 @@ public async Task StandbyMode_EndToEnd()
                 var webHostSettings = new WebHostSettings
                 {
                     IsSelfHost = true,
-                    LogPath = Path.Combine(testRootPath, "Logs"),
+                    LogPath = testRootPath,
                     SecretsPath = Path.Combine(testRootPath, "Secrets"),
                     ScriptPath = testRootPath,
                     TraceWriter = traceWriter
@@ -95,7 +96,7 @@ public async Task StandbyMode_EndToEnd()
                 TestHelpers.WaitForWebHost(httpClient);
 
                 var traces = traceWriter.Traces.ToArray();
-                Assert.Equal($"Creating StandbyMode placeholder function directory ({Path.GetTempPath()}Functions\\Standby)", traces[0].Message);
+                Assert.Equal($"Creating StandbyMode placeholder function directory ({Path.GetTempPath()}Functions\\Standby\\WWWRoot)", traces[0].Message);
                 Assert.Equal("StandbyMode placeholder function directory created", traces[1].Message);
 
                 // issue warmup request and verify
@@ -123,12 +124,16 @@ public async Task StandbyMode_EndToEnd()
 
                 await Task.Delay(2000);
 
+                // verify secrets directory
+
                 // 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")));
                 Assert.Equal(1, logLines.Count(p => p.Contains("Starting host specialization")));
+
+                WebScriptHostManager.ResetStandbyMode();
             }
         }
     }

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

@@ -27,6 +27,8 @@ public StandbyModeTests()
 
             _webHostResolver = new WebHostResolver(_settingsManager, new TestSecretManagerFactory(false), eventManagerMock.Object);
             _traceWriter = new TestTraceWriter(TraceLevel.Info);
+
+            WebScriptHostManager.ResetStandbyMode();
         }
 
         [Fact]

test/WebJobs.Script.Tests/WebHostResolverTests.cs

@@ -48,15 +48,15 @@ public void CreateScriptHostConfiguration_StandbyMode_ReturnsExpectedConfigurati
         {
             var settings = new WebHostSettings
             {
-                IsSelfHost = true
+                IsSelfHost = true,
+                ScriptPath = Path.Combine(Path.GetTempPath(), "Functions", "Standby")
             };
 
             var config = WebHostResolver.CreateScriptHostConfiguration(settings, true);
 
             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);
         }
     }
 }