Initial test at stopping direct log shipping in func

Author: bouwkast

tracer/missing-nullability-files.csv

@@ -485,6 +485,7 @@ src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Kafka/KafkaProduceSyncDelivery
 src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Kafka/KafkaProduceSyncIntegration.cs
 src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Kafka/Offset.cs
 src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Kafka/Partition.cs
+src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Logging/AzureFunctionsHostDetector.cs
 src/Datadog.Trace/ClrProfiler/AutoInstrumentation/MongoDb/IBsonDocumentProxy.cs
 src/Datadog.Trace/ClrProfiler/AutoInstrumentation/MongoDb/MongoDbTags.cs
 src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Msmq/MessageQueueTransactionType.cs

tracer/src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Logging/AzureFunctionsHostDetector.cs

@@ -0,0 +1,68 @@
+// <copyright file="AzureFunctionsHostDetector.cs" company="Datadog">
+// Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.
+// This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.
+// </copyright>
+
+using System;
+using System.Diagnostics;
+using System.Linq;
+using Datadog.Trace.Logging;
+
+internal static class AzureFunctionsHostDetector
+{
+    private static readonly IDatadogLogger Log = DatadogLogging.GetLoggerFor(typeof(AzureFunctionsHostDetector));
+
+    public static readonly bool IsRunningInFunctionsHost;
+
+    static AzureFunctionsHostDetector()
+    {
+        IsRunningInFunctionsHost = DetectIfFunctionsHost();
+
+        if (IsRunningInFunctionsHost)
+        {
+            Log.Information("Detected Azure Functions host process. Direct log submission will be disabled for ILogger to prevent duplicate logs.");
+        }
+    }
+
+    private static bool DetectIfFunctionsHost()
+    {
+        try
+        {
+            var process = Process.GetCurrentProcess();
+            var processName = process.ProcessName.ToLowerInvariant();
+
+            // Check if we're in a known Azure Functions host process
+            if (processName == "func" ||
+                processName.Contains("microsoft.azure.webjobs.script"))
+            {
+                var functionsRuntime = Environment.GetEnvironmentVariable("FUNCTIONS_WORKER_RUNTIME");
+                if (string.IsNullOrEmpty(functionsRuntime))
+                {
+                    return false; // Not Azure Functions
+                }
+
+                // The host process won't have this, but the worker will
+                var workerId = Environment.GetEnvironmentVariable("FUNCTIONS_WORKER_ID");
+                if (!string.IsNullOrEmpty(workerId))
+                {
+                    // We're in the worker process, not the host
+                    return false;
+                }
+
+                // function host will have these loaded (I think)
+                var hasHostAssemblies = AppDomain.CurrentDomain.GetAssemblies()
+                    .Any(a => a.GetName().Name == "Microsoft.Azure.WebJobs.Script.WebHost" ||
+                              a.GetName().Name == "Microsoft.Azure.WebJobs.Script");
+
+                return hasHostAssemblies;
+            }
+
+            return false;
+        }
+        catch (Exception ex)
+        {
+            Log.Error(ex, "Error detecting Azure Functions host process");
+            return false;
+        }
+    }
+}

tracer/src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Logging/ILogger/DirectSubmission/LoggerFactoryConstructorIntegration.cs

@@ -1,4 +1,4 @@
-// <copyright file="LoggerFactoryConstructorIntegration.cs" company="Datadog">
+// <copyright file="LoggerFactoryConstructorIntegration.cs" company="Datadog">
 // Unless explicitly stated otherwise all files in this repository are licensed under the Apache 2 License.
 // This product includes software developed at Datadog (https://www.datadoghq.com/). Copyright 2017 Datadog, Inc.
 // </copyright>
@@ -51,6 +51,11 @@ public static CallTargetReturn OnMethodEnd<TTarget>(TTarget instance, Exception?
                 return CallTargetReturn.GetDefault();
             }
 
+            if (AzureFunctionsHostDetector.IsRunningInFunctionsHost)
+            {
+                return CallTargetReturn.GetDefault();
+            }
+
             if (exception is not null)
             {
                 // If there's an exception during the constructor, things aren't going to work anyway

tracer/src/Datadog.Trace/ClrProfiler/AutoInstrumentation/Logging/ILogger/DirectSubmission/LoggerFactoryIntegrationCommon.cs

@@ -76,6 +76,13 @@ internal static bool TryAddDirectSubmissionLoggerProvider(TLoggerFactory loggerF
                 return false;
             }
 
+            if (AzureFunctionsHostDetector.IsRunningInFunctionsHost)
+            {
+                // We're in the host process, skip adding the provider entirely
+                Log.Debug("Skipping DirectSubmissionLoggerProvider creation in Azure Functions host process");
+                return false;
+            }
+
             var provider = new DirectSubmissionLoggerProvider(
                 TracerManager.Instance.DirectLogSubmission.Sink,
                 TracerManager.Instance.DirectLogSubmission.Settings.MinimumLevel,