submit metric for dynamodb stream type

Author: nhulston

datadog_lambda/metric.py

@@ -188,3 +188,12 @@ def submit_errors_metric(lambda_context):
         lambda_context (object): Lambda context dict passed to the function by AWS
     """
     submit_enhanced_metric("errors", lambda_context)
+
+def submit_dynamodb_stream_type_metric(event):
+    stream_view_type = (
+        event.get('Records', [{}])[0]
+        .get('dynamodb', {})
+        .get('StreamViewType')
+    )
+    if stream_view_type:
+        lambda_metric("datadog.serverless.dynamodb.stream.type", 1, timestamp=None, tags=[f"streamtype:{stream_view_type}"], force_async=True)

datadog_lambda/span_pointers.py

@@ -6,6 +6,8 @@
 
 from ddtrace._trace._span_pointer import _SpanPointerDirection
 from ddtrace._trace._span_pointer import _SpanPointerDescription
+
+from datadog_lambda.metric import submit_dynamodb_stream_type_metric
 from datadog_lambda.trigger import EventTypes
 
 
@@ -28,6 +30,7 @@ def calculate_span_pointers(
                 return _calculate_s3_span_pointers_for_event(event)
 
             elif event_source.equals(EventTypes.DYNAMODB):
+                submit_dynamodb_stream_type_metric(event) # Temporary metric. TODO eventually remove(@nhulston)
                 return _calculate_dynamodb_span_pointers_for_event(event)
 
     except Exception as e: