Refactoring the code

Author: surajitshil-03

src/Agent.Sdk/Knob/AgentKnobs.cs

@@ -203,12 +203,15 @@ public class AgentKnobs
         public static readonly Knob UseNode24 = new Knob(
             nameof(UseNode24),
             "Forces the agent to use Node 24 handler for all Node-based tasks",
+            new PipelineFeatureSource("UseNode24"),
             new RuntimeKnobSource("AGENT_USE_NODE24"),
             new EnvironmentKnobSource("AGENT_USE_NODE24"),
             new BuiltInDefaultKnobSource("false"));
+
         public static readonly Knob UseNode24InUnsupportedSystem = new Knob(
             nameof(UseNode24InUnsupportedSystem),
             "Forces the agent to use Node 24 handler for all Node-based tasks, even if it's in an unsupported system",
+            new PipelineFeatureSource("UseNode24InUnsupportedSystem"),
             new RuntimeKnobSource("AGENT_USE_NODE24_IN_UNSUPPORTED_SYSTEM"),
             new EnvironmentKnobSource("AGENT_USE_NODE24_IN_UNSUPPORTED_SYSTEM"),
             new BuiltInDefaultKnobSource("false"));
@@ -718,8 +721,8 @@ public class AgentKnobs
         public static readonly Knob UseNode24ToStartContainer = new Knob(
             nameof(UseNode24ToStartContainer),
             "If true, try to start container job using Node24, then fallback to Node20, then Node16.",
-            new RuntimeKnobSource("AZP_AGENT_USE_NODE24_TO_START_CONTAINER"),
             new PipelineFeatureSource("UseNode24ToStartContainer"),
+            new RuntimeKnobSource("AZP_AGENT_USE_NODE24_TO_START_CONTAINER"),
             new BuiltInDefaultKnobSource("false"));
 
         public static readonly Knob EnableNewMaskerAndRegexes = new Knob(

src/Agent.Worker/ExecutionContext.cs

@@ -62,6 +62,13 @@ public interface IExecutionContext : IAgentService, IKnobValueContext
         void QueueAttachFile(string type, string name, string filePath);
         ITraceWriter GetTraceWriter();
 
+        // correlation context for enhanced tracing
+        void SetCorrelationStep(string stepId);
+        void ClearCorrelationStep();
+        void SetCorrelationTask(string taskId);
+        void ClearCorrelationTask();
+        string BuildCorrelationId();
+
         // timeline record update methods
         void Start(string currentOperation = null);
         TaskResult Complete(TaskResult? result = null, string currentOperation = null, string resultCode = null);
@@ -93,7 +100,7 @@ public interface IExecutionContext : IAgentService, IKnobValueContext
         void PublishTaskRunnerTelemetry(Dictionary<string, string> taskRunnerData);
     }
 
-    public sealed class ExecutionContext : AgentService, IExecutionContext, IDisposable
+    public sealed class ExecutionContext : AgentService, IExecutionContext, ICorrelationContext, IDisposable
     {
         private const int _maxIssueCount = 10;
 
@@ -104,6 +111,8 @@ public sealed class ExecutionContext : AgentService, IExecutionContext, IDisposa
         private readonly HashSet<string> _outputvariables = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
         private readonly List<TaskRestrictions> _restrictions = new List<TaskRestrictions>();
         private readonly string _buildLogsFolderName = "buildlogs";
+        private readonly AsyncLocal<string> _correlationStep = new AsyncLocal<string>();
+        private readonly AsyncLocal<string> _correlationTask = new AsyncLocal<string>();
         private IAgentLogPlugin _logPlugin;
         private IPagingLogger _logger;
         private IJobServerQueue _jobServerQueue;
@@ -202,6 +211,9 @@ public override void Initialize(IHostContext hostContext)
             }
 
             _jobServerQueue = HostContext.GetService<IJobServerQueue>();
+
+            // Register this ExecutionContext for enhanced correlation
+            HostContext.CorrelationContextManager.SetCurrentExecutionContext(this);
         }
 
         public void CancelToken()
@@ -996,8 +1008,68 @@ public void PublishTaskRunnerTelemetry(Dictionary<string, string> taskRunnerData
             PublishTelemetry(taskRunnerData, IsAgentTelemetry: true);
         }
 
+        // Correlation context methods for enhanced tracing
+        public void SetCorrelationStep(string stepId)
+        {
+            _correlationStep.Value = stepId;
+        }
+
+        public void ClearCorrelationStep()
+        {
+            _correlationStep.Value = null;
+        }
+
+        public void SetCorrelationTask(string taskId)
+        {
+            _correlationTask.Value = taskId;
+        }
+
+        public void ClearCorrelationTask()
+        {
+            _correlationTask.Value = null;
+        }
+
+        public string BuildCorrelationId()
+        {
+            var step = _correlationStep.Value;
+            var task = _correlationTask.Value;
+
+            if (string.IsNullOrEmpty(step))
+            {
+                return string.IsNullOrEmpty(task) ? string.Empty : $"TASK-{ShortenGuid(task)}";
+            }
+
+            return string.IsNullOrEmpty(task) ? $"STEP-{ShortenGuid(step)}" : $"STEP-{ShortenGuid(step)}|TASK-{ShortenGuid(task)}";
+        }
+
+        /// <summary>
+        /// Shorten a GUID to first 12 characters for more readable logs while maintaining uniqueness
+        /// </summary>
+        private static string ShortenGuid(string guid)
+        {
+            if (string.IsNullOrEmpty(guid))
+                return guid;
+            
+            // Use first 12 characters total: 8 from first segment + 4 from second segment
+            // This ensures consistent output length regardless of input length
+            // e.g., "verylongstring-1234..." becomes "verylong1234" (12 chars)
+            // e.g., "60cf5508-70a7-..." becomes "60cf550870a7" (12 chars)
+            var parts = guid.Split('-');
+            if (parts.Length >= 2 && parts[0].Length >= 8 && parts[1].Length >= 4)
+            {
+                return parts[0].Substring(0, 8) + parts[1].Substring(0, 4);
+            }
+            
+            // Fallback: remove hyphens and take first 12 chars
+            var cleaned = guid.Replace("-", "");
+            return cleaned.Length > 12 ? cleaned.Substring(0, 12) : cleaned;
+        }
+
         public void Dispose()
         {
+            // Clear the correlation context registration
+            HostContext.CorrelationContextManager.ClearCurrentExecutionContext();
+            
             _cancellationTokenSource?.Dispose();
             _forceCompleteCancellationTokenSource?.Dispose();
 

src/Agent.Worker/Handlers/NodeHandler.cs

@@ -125,7 +125,7 @@ public async Task RunAsync()
                 ExecutionContext.PublishTaskRunnerTelemetry(telemetryData);
 
                 await VsoTaskLibManager.DownloadVsoTaskLibAsync(ExecutionContext);
-                
+
                 // Ensure compat vso-task-lib exist at the root of _work folder
                 // This will make vsts-agent work against 2015 RTM/QU1 TFS, since tasks in those version doesn't package with task lib
                 // Put the 0.5.5 version vso-task-lib into the root of _work/node_modules folder, so tasks are able to find those lib.
@@ -205,7 +205,7 @@ public async Task RunAsync()
                         }
                         else
                         {
-                            node20ResultsInGlibCErrorHost = await CheckIfNode20ResultsInGlibCError();
+                            node20ResultsInGlibCErrorHost = await CheckIfNodeResultsInGlibCError(NodeHandler.Node20_1Folder);
                             ExecutionContext.EmitHostNode20FallbackTelemetry(node20ResultsInGlibCErrorHost);
                             supportsNode20 = !node20ResultsInGlibCErrorHost;
                         }
@@ -218,8 +218,8 @@ public async Task RunAsync()
                         }
                         else
                         {
-                            node24ResultsInGlibCErrorHost = await CheckIfNode24ResultsInGlibCError();
-                            ExecutionContext.EmitHostNode24FallbackTelemetry(node24ResultsInGlibCErrorHost); // Add this method
+                            node24ResultsInGlibCErrorHost = await CheckIfNodeResultsInGlibCError(NodeHandler.Node24Folder);
+                            ExecutionContext.EmitHostNode24FallbackTelemetry(node24ResultsInGlibCErrorHost);
                             supportsNode24 = !node24ResultsInGlibCErrorHost;
                         }
                     }
@@ -317,21 +317,47 @@ public async Task RunAsync()
             }
         }
 
-        private async Task<bool> CheckIfNode20ResultsInGlibCError()
+        private async Task<bool> CheckIfNodeResultsInGlibCError(string nodeFolder)
         {
-            var node20 = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Externals), NodeHandler.Node20_1Folder, "bin", $"node{IOUtil.ExeExtension}");
-            List<string> nodeVersionOutput = await ExecuteCommandAsync(ExecutionContext, node20, "-v", requireZeroExitCode: false, showOutputOnFailureOnly: true);
-            var node20ResultsInGlibCError = WorkerUtilities.IsCommandResultGlibcError(ExecutionContext, nodeVersionOutput, out string nodeInfoLine);
+            var nodePath = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Externals), nodeFolder, "bin", $"node{IOUtil.ExeExtension}");
+            List<string> nodeVersionOutput = await ExecuteCommandAsync(ExecutionContext, nodePath, "-v", requireZeroExitCode: false, showOutputOnFailureOnly: true);
+            var nodeResultsInGlibCError = WorkerUtilities.IsCommandResultGlibcError(ExecutionContext, nodeVersionOutput, out string nodeInfoLine);
 
-            return node20ResultsInGlibCError;
+            return nodeResultsInGlibCError;
         }
-        private async Task<bool> CheckIfNode24ResultsInGlibCError()
+
+        private string GetNodeFolderWithFallback(string preferredNodeFolder, bool node20ResultsInGlibCError, bool node24ResultsInGlibCError, bool inContainer)
         {
-            var node24 = Path.Combine(HostContext.GetDirectory(WellKnownDirectory.Externals), NodeHandler.Node24Folder, "bin", $"node{IOUtil.ExeExtension}");
-            List<string> nodeVersionOutput = await ExecuteCommandAsync(ExecutionContext, node24, "-v", requireZeroExitCode: false, showOutputOnFailureOnly: true);
-            var node24ResultsInGlibCError = WorkerUtilities.IsCommandResultGlibcError(ExecutionContext, nodeVersionOutput, out string nodeInfoLine);
+            switch (preferredNodeFolder)
+            {
+                case var folder when folder == NodeHandler.Node24Folder:
+                    if (node24ResultsInGlibCError)
+                    {
+                        // Fallback to Node20, then Node16 if Node20 also fails
+                        if (node20ResultsInGlibCError)
+                        {
+                            NodeFallbackWarning("20", "16", inContainer);
+                            return NodeHandler.Node16Folder;
+                        }
+                        else
+                        {
+                            NodeFallbackWarning("24", "20", inContainer);
+                            return NodeHandler.Node20_1Folder;
+                        }
+                    }
+                    return NodeHandler.Node24Folder;
+
+                case var folder when folder == NodeHandler.Node20_1Folder:
+                    if (node20ResultsInGlibCError)
+                    {
+                        NodeFallbackWarning("20", "16", inContainer);
+                        return NodeHandler.Node16Folder;
+                    }
+                    return NodeHandler.Node20_1Folder;
 
-            return node24ResultsInGlibCError;
+                default:
+                    return preferredNodeFolder;
+            }
         }
 
         public string GetNodeLocation(bool node20ResultsInGlibCError, bool node24ResultsInGlibCError, bool inContainer)
@@ -350,39 +376,12 @@ public string GetNodeLocation(bool node20ResultsInGlibCError, bool node24Results
             if (taskHasNode24Data)
             {
                 Trace.Info($"Task.json has node24 handler data: {taskHasNode24Data}");
-
-                if (node24ResultsInGlibCError)
-                {
-                    // Fallback to Node20, then Node16 if Node20 also fails
-                    if (node20ResultsInGlibCError)
-                    {
-                        nodeFolder = NodeHandler.Node16Folder;
-                        Node16FallbackWarning(inContainer);
-                    }
-                    else
-                    {
-                        nodeFolder = NodeHandler.Node20_1Folder;
-                        Node20FallbackWarning(inContainer);
-                    }
-                }
-                else
-                {
-                    nodeFolder = NodeHandler.Node24Folder;
-                }
+                nodeFolder = GetNodeFolderWithFallback(NodeHandler.Node24Folder, node20ResultsInGlibCError, node24ResultsInGlibCError, inContainer);
             }
             else if (taskHasNode20_1Data)
             {
                 Trace.Info($"Task.json has node20_1 handler data: {taskHasNode20_1Data} node20ResultsInGlibCError = {node20ResultsInGlibCError}");
-
-                if (node20ResultsInGlibCError)
-                {
-                    nodeFolder = NodeHandler.Node16Folder;
-                    Node16FallbackWarning(inContainer);
-                }
-                else
-                {
-                    nodeFolder = NodeHandler.Node20_1Folder;
-                }
+                nodeFolder = GetNodeFolderWithFallback(NodeHandler.Node20_1Folder, node20ResultsInGlibCError, node24ResultsInGlibCError, inContainer);
             }
             else if (taskHasNode16Data)
             {
@@ -403,42 +402,15 @@ public string GetNodeLocation(bool node20ResultsInGlibCError, bool node24Results
             if (useNode24)
             {
                 Trace.Info($"Found UseNode24 knob, using node24 for node tasks: {useNode24}");
-
-                if (node24ResultsInGlibCError)
-                {
-                    // Fallback to Node20, then Node16 if Node20 also fails
-                    if (node20ResultsInGlibCError)
-                    {
-                        nodeFolder = NodeHandler.Node16Folder;
-                        Node16FallbackWarning(inContainer);
-                    }
-                    else
-                    {
-                        nodeFolder = NodeHandler.Node20_1Folder;
-                        Node20FallbackWarning(inContainer);
-                    }
-                }
-                else
-                {
-                    nodeFolder = NodeHandler.Node24Folder;
-                }
+                nodeFolder = GetNodeFolderWithFallback(NodeHandler.Node24Folder, node20ResultsInGlibCError, node24ResultsInGlibCError, inContainer);
             }
-            if (useNode20_1)
+            else if (useNode20_1)
             {
                 Trace.Info($"Found UseNode20_1 knob, using node20_1 for node tasks {useNode20_1} node20ResultsInGlibCError = {node20ResultsInGlibCError}");
-
-                if (node20ResultsInGlibCError)
-                {
-                    nodeFolder = NodeHandler.Node16Folder;
-                    Node16FallbackWarning(inContainer);
-                }
-                else
-                {
-                    nodeFolder = NodeHandler.Node20_1Folder;
-                }
+                nodeFolder = GetNodeFolderWithFallback(NodeHandler.Node20_1Folder, node20ResultsInGlibCError, node24ResultsInGlibCError, inContainer);
             }
 
-            if (useNode10)
+            else if (useNode10)
             {
                 Trace.Info($"Found UseNode10 knob, use node10 for node tasks: {useNode10}");
                 nodeFolder = NodeHandler.node10Folder;
@@ -501,37 +473,14 @@ public string GetNodeLocation(bool node20ResultsInGlibCError, bool node24Results
             return nodeHandlerHelper.GetNodeFolderPath(nodeFolder, HostContext);
         }
 
-        private void Node16FallbackWarning(bool inContainer)
+        private void NodeFallbackWarning(string fromVersion, string toVersion, bool inContainer)
         {
-            if (inContainer)
-            {
-                ExecutionContext.Warning($"The container operating system doesn't support Node20. Using Node16 instead. " +
-                                "Please upgrade the operating system of the container to remain compatible with future updates of tasks: " +
-                                "https://github.com/nodesource/distributions");
-            }
-            else
-            {
-                ExecutionContext.Warning($"The agent operating system doesn't support Node20. Using Node16 instead. " +
-                            "Please upgrade the operating system of the agent to remain compatible with future updates of tasks: " +
+            string systemType = inContainer ? "container" : "agent";
+            ExecutionContext.Warning($"The {systemType} operating system doesn't support Node{fromVersion}. Using Node{toVersion} instead. " +
+                            $"Please upgrade the operating system of the {systemType} to remain compatible with future updates of tasks: " +
                             "https://github.com/nodesource/distributions");
-            }
         }
 
-        private void Node20FallbackWarning(bool inContainer)
-        {
-            if (inContainer)
-            {
-                ExecutionContext.Warning($"The container operating system doesn't support Node24. Using Node20 instead. " +
-                                "Please upgrade the operating system of the container to remain compatible with future updates of tasks.");
-            }
-            else
-            {
-                ExecutionContext.Warning($"The agent operating system doesn't support Node24. Using Node20 instead. " +
-                            "Please upgrade the operating system of the agent to remain compatible with future updates of tasks.");
-            }
-        }
-
-
         private void OnDataReceived(object sender, ProcessDataReceivedEventArgs e)
         {
             // drop any outputs after the task get force completed.