feat: Add an option to disable the file system watcher. (#2536)

jaffinito · web-flow · commit 27d0ed005073 · 2024-06-12T10:27:34.000-07:00
diff --git a/src/Agent/NewRelic/Agent/Core/Config/Configuration.cs b/src/Agent/NewRelic/Agent/Core/Config/Configuration.cs
@@ -797,6 +797,8 @@ public partial class configurationService
         
         private bool forceNewTransactionOnNewThreadField;
         
+        private bool disableFileSystemWatcherField;
+        
         /// <summary>
         /// configurationService class constructor
         /// </summary>
@@ -810,6 +812,7 @@ public configurationService()
             this.sendDataOnExitThresholdField = ((float)(60000F));
             this.completeTransactionsOnThreadField = false;
             this.forceNewTransactionOnNewThreadField = false;
+            this.disableFileSystemWatcherField = false;
         }
         
         public string obscuringKey
@@ -1032,6 +1035,20 @@ public bool forceNewTransactionOnNewThread
             }
         }
         
+        [System.Xml.Serialization.XmlAttributeAttribute()]
+        [System.ComponentModel.DefaultValueAttribute(false)]
+        public bool disableFileSystemWatcher
+        {
+            get
+            {
+                return this.disableFileSystemWatcherField;
+            }
+            set
+            {
+                this.disableFileSystemWatcherField = value;
+            }
+        }
+        
         #region Clone method
         /// <summary>
         /// Create a clone of this configurationService object
diff --git a/src/Agent/NewRelic/Agent/Core/Config/Configuration.xsd b/src/Agent/NewRelic/Agent/Core/Config/Configuration.xsd
@@ -223,6 +223,14 @@
                             </xs:annotation>
                         </xs:attribute>
 
+                        <xs:attribute name="disableFileSystemWatcher" type="xs:boolean" default="false">
+                            <xs:annotation>
+                                <xs:documentation>
+                                    If disableFileSystemWatcher is set to true, then newrelic.config and instrumentation XML file changes, additions, or deletions will not be detected and applied after the application has been started.
+                                </xs:documentation>
+                            </xs:annotation>
+                        </xs:attribute>
+
                     </xs:complexType>
                 </xs:element>
 
diff --git a/src/Agent/NewRelic/Agent/Core/Config/ConfigurationTracker.cs b/src/Agent/NewRelic/Agent/Core/Config/ConfigurationTracker.cs
@@ -25,6 +25,12 @@ public class ConfigurationTracker : IDisposable
 
         public ConfigurationTracker(IConfigurationService configurationService, INativeMethods nativeMethods)
         {
+            if (configurationService.Configuration.DisableFileSystemWatcher)
+            {
+                Log.Debug("Live updates to newrelic.config will not be applied because they have been disabled by local configuration.");
+                return;
+            }
+
             _nativeMethods = nativeMethods;
             var fileName = configurationService.Configuration.NewRelicConfigFilePath;
             if (fileName == null)
diff --git a/src/Agent/NewRelic/Agent/Core/Configuration/DefaultConfiguration.cs b/src/Agent/NewRelic/Agent/Core/Configuration/DefaultConfiguration.cs
@@ -2058,6 +2058,19 @@ public IEnumerable<IDictionary<string, string>> IgnoredInstrumentation
             }
         }
 
+        public bool DisableFileSystemWatcher
+        {
+            get
+            {
+                if(ServerlessModeEnabled || !LoggingEnabled)
+                {
+                    return true;
+                }
+
+                return EnvironmentOverrides(_localConfiguration.service.disableFileSystemWatcher, "NEW_RELIC_DISABLE_FILE_SYSTEM_WATCHER");
+            }
+        }
+
         #region AI Monitoring
 
         public bool AiMonitoringEnabled
diff --git a/src/Agent/NewRelic/Agent/Core/Configuration/ReportedConfiguration.cs b/src/Agent/NewRelic/Agent/Core/Configuration/ReportedConfiguration.cs
@@ -662,6 +662,9 @@ public ReportedConfiguration(IConfiguration configuration)
         [JsonProperty("agent.instrumentation.ignore")]
         public IEnumerable<IDictionary<string, string>> IgnoredInstrumentation => _configuration.IgnoredInstrumentation;
 
+        [JsonProperty("agent.disable_file_system_watcher")]
+        public bool DisableFileSystemWatcher => _configuration.DisableFileSystemWatcher;
+
         [JsonProperty("agent.ai_monitoring.enabled")]
         public bool AiMonitoringEnabled => _configuration.AiMonitoringEnabled;
 
diff --git a/src/Agent/NewRelic/Agent/Core/Instrumentation/InstrumentationWatcher.cs b/src/Agent/NewRelic/Agent/Core/Instrumentation/InstrumentationWatcher.cs
@@ -1,6 +1,7 @@
 // Copyright 2020 New Relic, Inc. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+using NewRelic.Agent.Configuration;
 using NewRelic.Agent.Core.Utilities;
 using NewRelic.Agent.Core.Wrapper;
 using NewRelic.Core.Logging;
@@ -16,18 +17,26 @@ public class InstrumentationWatcher : IDisposable
 
         private readonly IInstrumentationService _instrumentationService;
         private readonly IWrapperService _wrapperService;
+        private readonly IConfigurationService _configurationService;
 
         private List<FileSystemWatcher> _fileWatchers;
         private SignalableAction _action;
 
-        public InstrumentationWatcher(IWrapperService wrapperService, IInstrumentationService instrumentationService)
+        public InstrumentationWatcher(IWrapperService wrapperService, IInstrumentationService instrumentationService, IConfigurationService configurationService)
         {
             _wrapperService = wrapperService;
             _instrumentationService = instrumentationService;
+            _configurationService = configurationService;
         }
 
         public void Start()
         {
+            if (_configurationService.Configuration.DisableFileSystemWatcher)
+            {
+                Log.Debug("Live instrumentation updates due to instrumentation file changes will not be applied because they have been disabled by local configuration.");
+                return;
+            }
+
             if (AgentInstallConfiguration.HomeExtensionsDirectory == null)
             {
                 Log.Warn("Live instrumentation updates due to instrumentation file changes will not be applied because HomeExtensionsDirectory is null.");
diff --git a/src/Agent/NewRelic/Agent/Extensions/NewRelic.Agent.Extensions/Configuration/IConfiguration.cs b/src/Agent/NewRelic/Agent/Extensions/NewRelic.Agent.Extensions/Configuration/IConfiguration.cs
@@ -212,7 +212,7 @@ public interface IConfiguration
         bool LoggingEnabled { get; }
         string LoggingLevel { get; }
         IEnumerable<IDictionary<string, string>> IgnoredInstrumentation { get; }
-
+        bool DisableFileSystemWatcher { get; }
         bool AiMonitoringEnabled { get; }
         bool AiMonitoringStreamingEnabled { get; }
         bool AiMonitoringRecordContentEnabled { get; }
diff --git a/tests/Agent/IntegrationTests/IntegrationTestHelpers/NewRelicConfigModifier.cs b/tests/Agent/IntegrationTests/IntegrationTestHelpers/NewRelicConfigModifier.cs
@@ -497,5 +497,11 @@ public void SetDebugStartupDelaySeconds(int delaySeconds)
             CommonUtils.ModifyOrCreateXmlAttributeInNewRelicConfig(_configFilePath, new[] { "configuration", },
                 "debugStartupDelaySeconds", delaySeconds.ToString());
         }
+
+        public NewRelicConfigModifier SetDisableFileSystemWatcher(bool enabled = true)
+        {
+            CommonUtils.ModifyOrCreateXmlAttributeInNewRelicConfig(_configFilePath, new[] { "configuration", "service" }, "disableFileSystemWatcher", enabled.ToString().ToLower());
+            return this;
+        }
     }
 }
diff --git a/tests/Agent/IntegrationTests/IntegrationTests/ReJit/NetCore/RejitAddFile.cs b/tests/Agent/IntegrationTests/IntegrationTests/ReJit/NetCore/RejitAddFile.cs
@@ -25,10 +25,12 @@ public abstract class RejitAddFileBase<TFixture> : NewRelicIntegrationTest<TFixt
         where TFixture:AspNetCoreReJitMvcApplicationFixture
     {
         private readonly AspNetCoreReJitMvcApplicationFixture _fixture;
+        private readonly bool _disableFileSystemWatcher;
 
-        protected RejitAddFileBase(TFixture fixture, ITestOutputHelper output) : base(fixture)
+        protected RejitAddFileBase(TFixture fixture, ITestOutputHelper output, bool disableFileSystemWatcher) : base(fixture)
         {
             _fixture = fixture;
+            _disableFileSystemWatcher = disableFileSystemWatcher;
 
             _fixture.TestLogger = output;
             _fixture.Actions(
@@ -37,6 +39,7 @@ protected RejitAddFileBase(TFixture fixture, ITestOutputHelper output) : base(fi
                     var configModifier = new NewRelicConfigModifier(_fixture.DestinationNewRelicConfigFilePath);
                     configModifier.SetLogLevel("finest");
                     configModifier.AutoInstrumentBrowserMonitoring(false);
+                    configModifier.SetDisableFileSystemWatcher(disableFileSystemWatcher);
                 },
                 exerciseApplication: () =>
                 {
@@ -61,20 +64,29 @@ public void Test()
             {
                 //transactions
                 new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/Home/Index", callCount = 1 },
-                new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 },
                 new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/Rejit/GetAddFile", callCount = 1 },
 
                 // Unscoped
                 new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", callCount = 1 },
-                new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", callCount = 1 },
-                new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", callCount = 2 },
 
                 // Scoped
                 new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", metricScope = "WebTransaction/MVC/Home/Index", callCount = 1 },
-                new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 },
                 new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", metricScope = "WebTransaction/MVC/Rejit/GetAddFile", callCount = 1 }
             };
 
+            // Id file system watcher is disabled, these won't exist.
+            if (_disableFileSystemWatcher)
+            {
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", callCount = 1 });
+            }
+            else
+            {
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 });
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", callCount = 1 });
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", callCount = 1 });
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", callCount = 2 });
+            }
+
             var metrics = CommonUtils.GetMetrics(_fixture.AgentLog);
             _fixture.TestLogger?.WriteLine(_fixture.AgentLog.GetFullLogAsString());
 
@@ -84,18 +96,26 @@ public void Test()
         }
     }
 
-    public class RejitAddFile : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixture>
+    public class RejitAddFileWithFileWatcherEnabled : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixture>
+    {
+        public RejitAddFileWithFileWatcherEnabled(AspNetCoreReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+            : base(fixture, output, false)
+        {
+        }
+    }
+
+    public class RejitAddFileWithFileWatcherDisabled : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixture>
     {
-        public RejitAddFile(AspNetCoreReJitMvcApplicationFixture fixture, ITestOutputHelper output)
-            : base(fixture, output)
+        public RejitAddFileWithFileWatcherDisabled(AspNetCoreReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+            : base(fixture, output, true)
         {
         }
     }
 
     public class RejitAddFileWithTieredCompilation : RejitAddFileBase<AspNetCoreReJitMvcApplicationFixtureWithTieredCompilation>
     {
         public RejitAddFileWithTieredCompilation(AspNetCoreReJitMvcApplicationFixtureWithTieredCompilation fixture, ITestOutputHelper output)
-            : base(fixture, output)
+            : base(fixture, output, false)
         {
         }
     }
diff --git a/tests/Agent/IntegrationTests/IntegrationTests/ReJit/NetFramework/RejitAddFile.cs b/tests/Agent/IntegrationTests/IntegrationTests/ReJit/NetFramework/RejitAddFile.cs
@@ -20,21 +20,25 @@ namespace NewRelic.Agent.IntegrationTests.ReJit.NetFramework
     /// Files: Integration.Testing.AddXmlFileTest.xml
     /// </summary>
     [NetFrameworkTest]
-    public class RejitAddFile : NewRelicIntegrationTest<AspNetFrameworkReJitMvcApplicationFixture>
+    public abstract class RejitAddFileBase<TFixture> : NewRelicIntegrationTest<TFixture>
+        where TFixture : AspNetFrameworkReJitMvcApplicationFixture
     {
         private readonly AspNetFrameworkReJitMvcApplicationFixture _fixture;
+        private readonly bool _disableFileSystemWatcher;
 
-        public RejitAddFile(AspNetFrameworkReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+        public RejitAddFileBase(TFixture fixture, ITestOutputHelper output, bool disableFileSystemWatcher)
             : base(fixture)
         {
             _fixture = fixture;
+            _disableFileSystemWatcher = disableFileSystemWatcher;
 
             _fixture.TestLogger = output;
             _fixture.Actions(
                 setupConfiguration: () =>
                 {
                     var configModifier = new NewRelicConfigModifier(_fixture.DestinationNewRelicConfigFilePath);
                     configModifier.AutoInstrumentBrowserMonitoring(false);
+                    configModifier.SetDisableFileSystemWatcher(disableFileSystemWatcher);
                 },
                 exerciseApplication: () =>
                 {
@@ -59,20 +63,29 @@ public void Test()
             {
 				//transactions
 				new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/HomeController/Index", CallCountAllHarvests = 1 },
-                new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 },
                 new Assertions.ExpectedMetric { metricName = @"WebTransaction/MVC/RejitController/GetAddFile", CallCountAllHarvests = 1 },
 
 				// Unscoped
 				new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", CallCountAllHarvests = 1 },
-                new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 },
-                new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", CallCountAllHarvests = 2 },
 
 				// Scoped
 				new Assertions.ExpectedMetric { metricName = @"DotNet/HomeController/Index", metricScope = "WebTransaction/MVC/HomeController/Index", CallCountAllHarvests = 1 },
-                new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 },
                 new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", metricScope = "WebTransaction/MVC/RejitController/GetAddFile", CallCountAllHarvests = 1 }
             };
 
+            // Id file system watcher is disabled, these won't exist.
+            if (_disableFileSystemWatcher)
+            {
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", CallCountAllHarvests = 1 });
+            }
+            else
+            {
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 });
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 });
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"Custom/MyCustomAddMetricName", metricScope = "WebTransaction/Custom/MyCustomAddMetricName", CallCountAllHarvests = 1 });
+                expectedMetrics.Add(new Assertions.ExpectedMetric { metricName = @"DotNet/RejitController/GetAddFile", CallCountAllHarvests = 2 });
+            }
+
             var metrics = CommonUtils.GetMetrics(_fixture.AgentLog);
             _fixture.TestLogger?.WriteLine(_fixture.AgentLog.GetFullLogAsString());
 
@@ -81,4 +94,20 @@ public void Test()
             );
         }
     }
+
+    public class RejitAddFileWithFileWatcherEnabled : RejitAddFileBase<AspNetFrameworkReJitMvcApplicationFixture>
+    {
+        public RejitAddFileWithFileWatcherEnabled(AspNetFrameworkReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+            : base(fixture, output, false)
+        {
+        }
+    }
+
+    public class RejitAddFileWithFileWatcherDisabled : RejitAddFileBase<AspNetFrameworkReJitMvcApplicationFixture>
+    {
+        public RejitAddFileWithFileWatcherDisabled(AspNetFrameworkReJitMvcApplicationFixture fixture, ITestOutputHelper output)
+            : base(fixture, output, true)
+        {
+        }
+    }
 }
diff --git a/tests/Agent/UnitTests/Core.UnitTest/Configuration/DefaultConfigurationTests.cs b/tests/Agent/UnitTests/Core.UnitTest/Configuration/DefaultConfigurationTests.cs
@@ -4023,6 +4023,39 @@ public void LoggingLevelValueIsCached()
 
         #endregion Agent Logs
 
+        [TestCase(false, null, true, false, ExpectedResult = false)] // default
+        [TestCase(true, null, true, false, ExpectedResult = true)]
+        [TestCase(false, true, true, false, ExpectedResult = true)]
+        [TestCase(true, false, true, false, ExpectedResult = false)]
+        [TestCase(false, null, false, false, ExpectedResult = true)]
+        [TestCase(false, null, false, true, ExpectedResult = true)]
+        [TestCase(false, null, true, true, ExpectedResult = true)]
+        [TestCase(true, null, false, false, ExpectedResult = true)]
+        [TestCase(true, null, false, true, ExpectedResult = true)]
+        [TestCase(true, null, true, true, ExpectedResult = true)]
+        [TestCase(false, true, false, false, ExpectedResult = true)]
+        [TestCase(false, true, false, true, ExpectedResult = true)]
+        [TestCase(false, true, true, true, ExpectedResult = true)]
+        [TestCase(true, false, false, false, ExpectedResult = true)]
+        [TestCase(true, false, false, true, ExpectedResult = true)]
+        [TestCase(true, false, true, true, ExpectedResult = true)]
+        public bool ValidateDisableFileSystemWatcher(bool localWatcherDisabled, bool? envWatcherDisabled, bool loggingEnabled, bool serverlessMode)
+        {
+            // Setup config values
+            _localConfig.service.disableFileSystemWatcher = localWatcherDisabled;
+
+            if (envWatcherDisabled.HasValue)
+            {
+                Mock.Arrange(() => _environment.GetEnvironmentVariable("NEW_RELIC_DISABLE_FILE_SYSTEM_WATCHER")).Returns(envWatcherDisabled.ToString().ToLower());
+            }
+
+            _localConfig.log.enabled = loggingEnabled;
+            Mock.Arrange(() => _bootstrapConfiguration.ServerlessModeEnabled).Returns(serverlessMode);
+
+            // test
+            return _defaultConfig.DisableFileSystemWatcher;
+        }
+
         private void CreateDefaultConfiguration()
         {
             _defaultConfig = new TestableDefaultConfiguration(_environment, _localConfig, _serverConfig, _runTimeConfig, _securityPoliciesConfiguration, _bootstrapConfiguration, _processStatic, _httpRuntimeStatic, _configurationManagerStatic, _dnsStatic);
diff --git a/tests/Agent/UnitTests/Core.UnitTest/DataTransport/AgentSettingsTests.cs b/tests/Agent/UnitTests/Core.UnitTest/DataTransport/AgentSettingsTests.cs
diff --git a/tests/Agent/UnitTests/Core.UnitTest/DataTransport/ConnectModelTests.cs b/tests/Agent/UnitTests/Core.UnitTest/DataTransport/ConnectModelTests.cs
diff --git a/tests/Agent/UnitTests/Core.UnitTest/DataTransport/ExhaustiveTestConfiguration.cs b/tests/Agent/UnitTests/Core.UnitTest/DataTransport/ExhaustiveTestConfiguration.cs

Original file line number	Diff line number	Diff line change
`@@ -497,5 +497,11 @@ public void SetDebugStartupDelaySeconds(int delaySeconds)`
`497`	`497`	`CommonUtils.ModifyOrCreateXmlAttributeInNewRelicConfig(_configFilePath, new[] { "configuration", },`
`498`	`498`	`"debugStartupDelaySeconds", delaySeconds.ToString());`
`499`	`499`	`}`
	`500`	`+`
	`501`	`+ public NewRelicConfigModifier SetDisableFileSystemWatcher(bool enabled = true)`
	`502`	`+ {`
	`503`	`+ CommonUtils.ModifyOrCreateXmlAttributeInNewRelicConfig(_configFilePath, new[] { "configuration", "service" }, "disableFileSystemWatcher", enabled.ToString().ToLower());`
	`504`	`+ return this;`
	`505`	`+ }`
`500`	`506`	`}`
`501`	`507`	`}`