feat: PoC for adding lambda function trigger identifier

instrumentation/opentelemetry-instrumentation-aws-lambda/src/opentelemetry/instrumentation/aws_lambda/__init__.py

@@ -167,6 +167,43 @@ def _determine_parent_context(
     return parent_context
 
 
+def _get_trigger_info(
+        lambda_event: Any,
+) -> str:
+    if not lambda_event or not isinstance(lambda_event, dict):
+        return
+
+    # elb
+    if lambda_event.get("headers"):
+        if "host" in lambda_event["headers"]:
+            return lambda_event["headers"]["host"]
+
+    # sns, sqs, s3
+    records = lambda_event.get("Records")
+    if not records or not isinstance(records, list) or not records[0]:
+        return
+
+    event_content = records[0]
+    event_source = event_content.get("eventSource")
+    if not event_source:
+        event_source = event_content.get("EventSource")
+    if not event_source:
+        return
+
+    if event_source == "aws:sns":
+        sns_tag = event_content.get("Sns")
+        if not sns_tag:
+            return
+        return sns_tag.get("TopicArn")
+    elif event_source == "aws:sqs":
+        return event_content.get("eventSourceARN")
+    elif event_source == "aws:s3":
+        s3_tag = event_content.get("s3")
+        if not s3_tag or not s3_tag["bucket"]:
+            return
+        return s3_tag["bucket"].get("arn")
+
+
 def _determine_links() -> Optional[Sequence[Link]]:
     """Determine if a Link should be added to the Span based on the
     environment variable `_X_AMZN_TRACE_ID`.
@@ -370,6 +407,11 @@ def _instrumented_lambda_handler_call(  # noqa pylint: disable=too-many-branches
                         result.get("statusCode"),
                     )
 
+            # Add information of trigger to span if available
+            trigger_id = _get_trigger_info(lambda_event)
+            if trigger_id:
+                span.set_attribute("faas.trigger_id", trigger_id)
+
         now = time.time()
         _tracer_provider = tracer_provider or get_tracer_provider()
         if hasattr(_tracer_provider, "force_flush"):

instrumentation/opentelemetry-instrumentation-aws-lambda/tests/test_aws_lambda_instrumentation_manual.py

@@ -75,6 +75,9 @@ def __init__(self, aws_request_id, invoked_function_arn):
 MOCK_W3C_TRACE_STATE_KEY = "vendor_specific_key"
 MOCK_W3C_TRACE_STATE_VALUE = "test_value"
 
+MOCK_TRIGGER_ARN = "arn:aws:trigger:us-east-2:123456789012:abc.xyz"
+MOCK_HOST = "lambda-alb-123578498.us-east-1.elb.amazonaws.com"
+
 
 def mock_execute_lambda(event=None):
     """Mocks the AWS Lambda execution.
@@ -428,3 +431,51 @@ def test_no_op_tracer_provider(self):
         spans = self.memory_exporter.get_finished_spans()
         assert spans is not None
         self.assertEqual(len(spans), 0)
+
+    def test_set_trigger_info(self):
+        @dataclass
+        class TestCase:
+            name: str
+            expected_link_span_attr_val: str
+            event_payload: dict
+
+        tests = [
+            TestCase(
+                name="valid_sns_event",
+                expected_link_span_attr_val=MOCK_TRIGGER_ARN,
+                event_payload={"Records": [{"EventSource": "aws:sns", "Sns": {"TopicArn": MOCK_TRIGGER_ARN}}]},
+            ),
+            TestCase(
+                name="valid_sqs_event",
+                expected_link_span_attr_val=MOCK_TRIGGER_ARN,
+                event_payload={"Records": [{"eventSource": "aws:sqs", "eventSourceARN": MOCK_TRIGGER_ARN}]},
+            ),
+            TestCase(
+                name="valid_s3_event",
+                expected_link_span_attr_val=MOCK_TRIGGER_ARN,
+                event_payload={"Records": [{"eventSource": "aws:s3", "s3": {"bucket": {"arn": MOCK_TRIGGER_ARN}}}]},
+            ),
+            TestCase(
+                name="valid_elb_event",
+                expected_link_span_attr_val=MOCK_HOST,
+                event_payload={"headers": {"host": MOCK_HOST}},
+            ),
+        ]
+        for test in tests:
+            AwsLambdaInstrumentor().instrument()
+            mock_execute_lambda(test.event_payload)
+            spans = self.memory_exporter.get_finished_spans()
+            assert spans
+
+            self.assertEqual(len(spans), 1)
+            span = spans[0]
+
+            self.assertSpanHasAttributes(
+                span,
+                {
+                    "faas.trigger_id": test.expected_link_span_attr_val,
+                },
+            )
+
+            self.memory_exporter.clear()
+            AwsLambdaInstrumentor().uninstrument()