Fix telemetry reporting for mutable settings

Author: andrewlock

tracer/src/Datadog.Trace/ClrProfiler/AutoInstrumentation/ManualInstrumentation/Tracer/ConfigureIntegration.cs

@@ -64,12 +64,13 @@ internal static void ConfigureSettingsWithManualOverrides(Dictionary<string, obj
         // TODO: these will eventually live elsewhere
         var currentSettings = tracerSettings.MutableSettings;
 
+        var manualTelemetry = new ConfigurationTelemetry();
         var newMutableSettings = MutableSettings.CreateUpdatedMutableSettings(
             dynamicConfig,
             manualConfig,
             initialSettings,
             tracerSettings,
-            TelemetryFactory.Config,
+            manualTelemetry,
             new OverrideErrorLog()); // TODO: We'll later report these
 
         var isSameMutableSettings = currentSettings.Equals(newMutableSettings);
@@ -90,6 +91,12 @@ internal static void ConfigureSettingsWithManualOverrides(Dictionary<string, obj
         if (isSameMutableSettings && isSameExporterSettings)
         {
             Log.Debug("No changes detected in the new configuration in code");
+            // Even though there were no "real" changes, there may be _effective_ changes in telemetry that
+            // need to be recorded (e.g. the customer set the value in code but it was already set via
+            // env vars). We _should_ record exporter settings too, but that introduces a bunch of complexity
+            // which we'll resolve later anyway, so just have that gap for now (it's very niche).
+            // If there are changes, they're recorded automatically in ConfigureInternal
+            manualTelemetry.CopyTo(TelemetryFactory.Config);
             return;
         }
 

tracer/src/Datadog.Trace/Configuration/DynamicConfigurationManager.cs

@@ -80,7 +80,7 @@ private static void OnConfigurationChanged(IConfigurationSource dynamicConfig)
                 tracerSettings,
                 // TODO: In the future this will 'live' elsewhere
                 currentSettings: tracerSettings.MutableSettings,
-                TelemetryFactory.Config,
+                new ConfigurationTelemetry(),
                 new OverrideErrorLog()); // TODO: We'll later report these
         }
 
@@ -90,7 +90,7 @@ private static void OnConfigurationChanged(
             MutableSettings initialSettings,
             TracerSettings tracerSettings,
             MutableSettings currentSettings,
-            IConfigurationTelemetry telemetry,
+            ConfigurationTelemetry telemetry,
             OverrideErrorLog errorLog)
         {
             var newMutableSettings = MutableSettings.CreateUpdatedMutableSettings(
@@ -104,6 +104,12 @@ private static void OnConfigurationChanged(
             if (currentSettings.Equals(newMutableSettings))
             {
                 Log.Debug("No changes detected in the new dynamic configuration");
+                // Even though there were no "real" changes, there may be _effective_ changes in telemetry that
+                // need to be recorded (e.g. the customer set the value in code but it was already set via
+                // env vars). We _should_ record exporter settings too, but that introduces a bunch of complexity
+                // which we'll resolve later anyway, so just have that gap for now (it's very niche).
+                // If there are changes, they're recorded automatically in ConfigureInternal
+                telemetry.CopyTo(TelemetryFactory.Config);
                 return;
             }
 

tracer/src/Datadog.Trace/Telemetry/TelemetryController.cs

@@ -95,6 +95,14 @@ public void RecordTracerSettings(TracerSettings settings, string defaultServiceN
         // ImmutableTracerSettings, at which point that config would become "current", so we
         // need to keep it around
         settings.Telemetry.CopyTo(_configuration);
+        // if the mutable settings have changed since the start, re-record them
+        // to ensure they have the correct values. This is a temporary measure before
+        // we fully extract mutable settings
+        if (!ReferenceEquals(settings.MutableSettings, settings.InitialMutableSettings))
+        {
+            settings.MutableSettings.Telemetry.CopyTo(_configuration);
+        }
+
         _application.RecordTracerSettings(settings, defaultServiceName);
         _namingVersion = ((int)settings.MetadataSchemaVersion).ToString();
         _logTagBuilder.Update(settings);