Add Service and Environment dimensions to EMF metrics when Application Signals is enabled

When both OTEL_AWS_APPLICATION_SIGNALS_ENABLED and
OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED are true, inject
"Service" and "Environment" dimensions into EMF metrics.

- Service: extracted from resource via get_service_attribute(), falls
  back to "UnknownService"
- Environment: extracted from deployment.environment resource attribute,
  falls back to "lambda:default"
- Case-insensitive check prevents overwriting user-set dimensions
- Lambda wrapper sets OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED=true
  by default

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: syed-ahsan-ishtiaque

CHANGELOG.md

@@ -11,6 +11,8 @@ For any change that affects end users of this package, please add an entry under
 If your change does not need a CHANGELOG entry, add the "skip changelog" label to your PR.
 
 ## Unreleased
+- Add Service and Environment dimensions to EMF metrics when Application Signals EMF export is enabled
+  ([#548](https://github.com/aws-observability/aws-otel-python-instrumentation/pull/548))
 - Add Resource and CFN Attributes for Bedrock AgentCore spans
   ([#495](https://github.com/aws-observability/aws-otel-python-instrumentation/pull/495))
 - Add botocore instrumentation extension for Bedrock AgentCore services with span attributes

aws-opentelemetry-distro/src/amazon/opentelemetry/distro/exporter/aws/metrics/base_emf_exporter.py

@@ -6,11 +6,13 @@
 import json
 import logging
 import math
+import os
 import time
 from abc import ABC, abstractmethod
 from collections import defaultdict
 from typing import Any, Dict, List, Optional, Tuple
 
+from amazon.opentelemetry.distro._aws_resource_attribute_configurator import get_service_attribute
 from opentelemetry.sdk.metrics import Counter
 from opentelemetry.sdk.metrics import Histogram as HistogramInstr
 from opentelemetry.sdk.metrics import ObservableCounter, ObservableGauge, ObservableUpDownCounter, UpDownCounter
@@ -28,6 +30,7 @@
 )
 from opentelemetry.sdk.metrics.view import ExponentialBucketHistogramAggregation
 from opentelemetry.sdk.resources import Resource
+from opentelemetry.semconv.resource import ResourceAttributes
 from opentelemetry.util.types import Attributes
 
 logger = logging.getLogger(__name__)
@@ -184,6 +187,51 @@ def _get_dimension_names(self, attributes: Attributes) -> List[str]:
         # For now, use all attributes as dimensions
         return list(attributes.keys())
 
+    def _has_dimension_case_insensitive(self, dimension_names: List[str], dimension_to_check: str) -> bool:
+        """Check if dimension already exists (case-insensitive match)."""
+        dimension_lower = dimension_to_check.lower()
+        return any(dim.lower() == dimension_lower for dim in dimension_names)
+
+    @staticmethod
+    def _is_application_signals_emf_export_enabled() -> bool:
+        """Check if Application Signals EMF export is enabled.
+
+        Returns True only if BOTH:
+        - OTEL_AWS_APPLICATION_SIGNALS_ENABLED is true
+        - OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED is true
+        """
+        app_signals_enabled = os.environ.get("OTEL_AWS_APPLICATION_SIGNALS_ENABLED", "false").lower() == "true"
+        emf_export_enabled = os.environ.get("OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED", "false").lower() == "true"
+        return app_signals_enabled and emf_export_enabled
+
+    def _add_application_signals_dimensions(
+        self, dimension_names: List[str], emf_log: Dict, resource: Resource
+    ) -> None:
+        """Add Service and Environment dimensions if not already present (case-insensitive)."""
+        if not self._is_application_signals_emf_export_enabled():
+            return
+
+        # Add Service dimension if not already set by user
+        if not self._has_dimension_case_insensitive(dimension_names, "Service"):
+            if resource:
+                service_name, _ = get_service_attribute(resource)
+            else:
+                service_name = "UnknownService"
+            dimension_names.insert(0, "Service")
+            emf_log["Service"] = str(service_name)
+
+        # Add Environment dimension if not already set by user
+        if not self._has_dimension_case_insensitive(dimension_names, "Environment"):
+            environment_value = None
+            if resource and resource.attributes:
+                environment_value = resource.attributes.get(ResourceAttributes.DEPLOYMENT_ENVIRONMENT)
+            if not environment_value:
+                environment_value = "lambda:default"
+            # Insert after Service if it exists, otherwise at the beginning
+            insert_pos = 1 if "Service" in dimension_names else 0
+            dimension_names.insert(insert_pos, "Environment")
+            emf_log["Environment"] = str(environment_value)
+
     def _get_attributes_key(self, attributes: Attributes) -> str:
         """
         Create a hashable key from attributes for grouping metrics.
@@ -493,6 +541,9 @@ def _create_emf_log(
         for name, value in all_attributes.items():
             emf_log[name] = str(value)
 
+        # Add Service and Environment dimensions if Application Signals EMF export is enabled
+        self._add_application_signals_dimensions(dimension_names, emf_log, resource)
+
         # Add CloudWatch Metrics if we have metrics, include dimensions only if they exist
         if metric_definitions:
             cloudwatch_metric = {"Namespace": self.namespace, "Metrics": metric_definitions}

aws-opentelemetry-distro/tests/amazon/opentelemetry/distro/exporter/aws/metrics/test_base_emf_exporter.py

@@ -1,8 +1,9 @@
 # Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
+import os
 import unittest
-from unittest.mock import Mock
+from unittest.mock import Mock, patch
 
 from amazon.opentelemetry.distro.exporter.aws.metrics.base_emf_exporter import BaseEmfExporter, MetricRecord
 from opentelemetry.sdk.metrics.export import MetricExportResult
@@ -286,6 +287,173 @@ def test_export_failure_handling(self):
         result = self.exporter.export(metrics_data)
         self.assertEqual(result, MetricExportResult.FAILURE)
 
+    def test_has_dimension_case_insensitive(self):
+        """Test case-insensitive dimension checking."""
+        dimension_names = ["Service", "Environment", "operation"]
+
+        # Exact match
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "Service"))
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "Environment"))
+
+        # Case variations
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "service"))
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "SERVICE"))
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "environment"))
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "ENVIRONMENT"))
+        self.assertTrue(self.exporter._has_dimension_case_insensitive(dimension_names, "OPERATION"))
+
+        # Non-existent dimension
+        self.assertFalse(self.exporter._has_dimension_case_insensitive(dimension_names, "NotExists"))
+
+        # Empty list
+        self.assertFalse(self.exporter._has_dimension_case_insensitive([], "Service"))
+
+    def test_add_application_signals_dimensions_disabled(self):
+        """Test that dimensions are not added when feature is disabled."""
+        # Default exporter has feature disabled
+        dimension_names = ["operation"]
+        emf_log = {}
+        resource = Resource.create({"service.name": "my-service", "deployment.environment": "production"})
+
+        self.exporter._add_application_signals_dimensions(dimension_names, emf_log, resource)
+
+        # Dimensions should not be added
+        self.assertEqual(dimension_names, ["operation"])
+        self.assertNotIn("Service", emf_log)
+        self.assertNotIn("Environment", emf_log)
+
+    @patch.dict(
+        os.environ,
+        {"OTEL_AWS_APPLICATION_SIGNALS_ENABLED": "true", "OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED": "true"},
+    )
+    def test_add_application_signals_dimensions_enabled(self):
+        """Test that dimensions are added when feature is enabled."""
+        exporter = ConcreteEmfExporter(namespace="TestNamespace")
+        dimension_names = ["operation"]
+        emf_log = {}
+        resource = Resource.create({"service.name": "my-service", "deployment.environment": "production"})
+
+        exporter._add_application_signals_dimensions(dimension_names, emf_log, resource)
+
+        # Service and Environment should be added at the beginning
+        self.assertEqual(dimension_names, ["Service", "Environment", "operation"])
+        self.assertEqual(emf_log["Service"], "my-service")
+        self.assertEqual(emf_log["Environment"], "production")
+
+    @patch.dict(
+        os.environ,
+        {"OTEL_AWS_APPLICATION_SIGNALS_ENABLED": "true", "OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED": "true"},
+    )
+    def test_add_application_signals_dimensions_fallback_values(self):
+        """Test fallback values when resource attributes are not available."""
+        exporter = ConcreteEmfExporter(namespace="TestNamespace")
+        dimension_names = ["operation"]
+        emf_log = {}
+        # Resource without deployment.environment
+        resource = Resource.create({"service.name": "my-service"})
+
+        exporter._add_application_signals_dimensions(dimension_names, emf_log, resource)
+
+        # Service should use service.name, Environment should fallback to lambda:default
+        self.assertIn("Service", dimension_names)
+        self.assertIn("Environment", dimension_names)
+        self.assertEqual(emf_log["Service"], "my-service")
+        self.assertEqual(emf_log["Environment"], "lambda:default")
+
+    @patch.dict(
+        os.environ,
+        {"OTEL_AWS_APPLICATION_SIGNALS_ENABLED": "true", "OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED": "true"},
+    )
+    def test_add_application_signals_dimensions_no_resource(self):
+        """Test fallback when resource is None."""
+        exporter = ConcreteEmfExporter(namespace="TestNamespace")
+        dimension_names = ["operation"]
+        emf_log = {}
+
+        exporter._add_application_signals_dimensions(dimension_names, emf_log, None)
+
+        # Should use fallback values
+        self.assertIn("Service", dimension_names)
+        self.assertIn("Environment", dimension_names)
+        self.assertEqual(emf_log["Service"], "UnknownService")
+        self.assertEqual(emf_log["Environment"], "lambda:default")
+
+    @patch.dict(
+        os.environ,
+        {"OTEL_AWS_APPLICATION_SIGNALS_ENABLED": "true", "OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED": "true"},
+    )
+    def test_add_application_signals_dimensions_service_already_set(self):
+        """Test that Service dimension is not overwritten if already set (case-insensitive)."""
+        exporter = ConcreteEmfExporter(namespace="TestNamespace")
+
+        # User has set "service" (lowercase)
+        dimension_names = ["service", "operation"]
+        emf_log = {"service": "user-service"}
+        resource = Resource.create({"service.name": "my-service", "deployment.environment": "production"})
+
+        exporter._add_application_signals_dimensions(dimension_names, emf_log, resource)
+
+        # Service should NOT be added (case-insensitive match), but Environment should be
+        self.assertIn("Environment", dimension_names)
+        self.assertNotIn("Service", dimension_names)  # "Service" not added because "service" exists
+        self.assertEqual(emf_log.get("service"), "user-service")  # User value preserved
+        self.assertEqual(emf_log.get("Environment"), "production")
+
+    @patch.dict(
+        os.environ,
+        {"OTEL_AWS_APPLICATION_SIGNALS_ENABLED": "true", "OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED": "true"},
+    )
+    def test_add_application_signals_dimensions_environment_already_set(self):
+        """Test that Environment dimension is not overwritten if already set (case-insensitive)."""
+        exporter = ConcreteEmfExporter(namespace="TestNamespace")
+
+        # User has set "ENVIRONMENT" (uppercase)
+        dimension_names = ["ENVIRONMENT", "operation"]
+        emf_log = {"ENVIRONMENT": "user-environment"}
+        resource = Resource.create({"service.name": "my-service", "deployment.environment": "production"})
+
+        exporter._add_application_signals_dimensions(dimension_names, emf_log, resource)
+
+        # Environment should NOT be added (case-insensitive match), but Service should be
+        self.assertIn("Service", dimension_names)
+        self.assertNotIn("Environment", dimension_names)  # "Environment" not added because "ENVIRONMENT" exists
+        self.assertEqual(emf_log.get("Service"), "my-service")
+        self.assertEqual(emf_log.get("ENVIRONMENT"), "user-environment")  # User value preserved
+
+    @patch.dict(
+        os.environ,
+        {"OTEL_AWS_APPLICATION_SIGNALS_ENABLED": "true", "OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED": "true"},
+    )
+    def test_create_emf_log_with_application_signals_enabled(self):
+        """Test EMF log creation with Application Signals EMF export enabled."""
+        exporter = ConcreteEmfExporter(namespace="TestNamespace")
+
+        record = exporter._create_metric_record("test_metric", "Count", "Test")
+        record.value = 50.0
+        record.timestamp = 1234567890
+        record.attributes = {"operation": "test"}
+
+        records = [record]
+        resource = Resource.create(
+            {
+                "service.name": "test-service",
+                "deployment.environment": "production",
+            }
+        )
+
+        result = exporter._create_emf_log(records, resource, 1234567890)
+
+        # Check that Service and Environment dimensions were added
+        self.assertEqual(result["Service"], "test-service")
+        self.assertEqual(result["Environment"], "production")
+
+        # Check CloudWatch metrics dimensions include Service and Environment
+        cw_metrics = result["_aws"]["CloudWatchMetrics"][0]
+        dimensions = cw_metrics["Dimensions"][0]
+        self.assertIn("Service", dimensions)
+        self.assertIn("Environment", dimensions)
+        self.assertIn("operation", dimensions)
+
 
 if __name__ == "__main__":
     unittest.main()

aws-opentelemetry-distro/tests/amazon/opentelemetry/distro/test_aws_opentelementry_configurator.py

@@ -1327,7 +1327,9 @@ def test_create_emf_exporter_lambda_without_valid_headers(
             result = _create_emf_exporter()
 
             self.assertEqual(result, mock_exporter_instance)
-            mock_console_exporter.assert_called_once_with(namespace="test-namespace")
+            mock_console_exporter.assert_called_once_with(
+                namespace="test-namespace",
+            )
 
     @patch("amazon.opentelemetry.distro.aws_opentelemetry_configurator._fetch_logs_header")
     @patch("amazon.opentelemetry.distro.aws_opentelemetry_configurator._is_lambda_environment")
@@ -1474,7 +1476,9 @@ def test_create_emf_exporter_lambda_without_valid_headers_none_namespace(
             result = _create_emf_exporter()
 
             self.assertEqual(result, mock_exporter_instance)
-            mock_console_exporter.assert_called_once_with(namespace=None)
+            mock_console_exporter.assert_called_once_with(
+                namespace=None,
+            )
 
     @patch("amazon.opentelemetry.distro.aws_opentelemetry_configurator._fetch_logs_header")
     @patch("amazon.opentelemetry.distro.aws_opentelemetry_configurator._is_lambda_environment")

lambda-layer/src/otel-instrument

@@ -115,6 +115,10 @@ if [ -z "${OTEL_AWS_APPLICATION_SIGNALS_ENABLED}" ]; then
     export OTEL_AWS_APPLICATION_SIGNALS_ENABLED="true";
 fi
 
+if [ -z "${OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED}" ]; then
+    export OTEL_AWS_APPLICATION_SIGNALS_EMF_EXPORT_ENABLED="true";
+fi
+
 # - If Application Signals is enabled
 
 if [ "${OTEL_AWS_APPLICATION_SIGNALS_ENABLED}" = "true" ]; then