Refactoring to allow lazy loading of datadog.api

datadog_lambda/metric.py

@@ -45,15 +45,24 @@ def lambda_metric(metric_name, value, timestamp=None, tags=None, force_async=Fal
     Otherwise, the metrics will be submitted to the Datadog API
     periodically and at the end of the function execution in a
     background thread.
+
+    Note that if the extension is present, it will override the DD_FLUSH_TO_LOG value
+    and always use the layer to send metrics to the extension
     """
     flush_to_logs = os.environ.get("DD_FLUSH_TO_LOG", "").lower() == "true"
     tags = tag_dd_lambda_layer(tags)
 
-    if flush_to_logs or (force_async and not should_use_extension):
-        write_metric_point_to_stdout(metric_name, value, timestamp=timestamp, tags=tags)
-    else:
-        logger.debug("Sending metric %s to Datadog via lambda layer", metric_name)
+    if should_use_extension:
         lambda_stats.distribution(metric_name, value, tags=tags, timestamp=timestamp)
+    else:
+        if flush_to_logs or force_async:
+            write_metric_point_to_stdout(
+                metric_name, value, timestamp=timestamp, tags=tags
+            )
+        else:
+            lambda_stats.distribution(
+                metric_name, value, tags=tags, timestamp=timestamp
+            )
 
 
 def write_metric_point_to_stdout(metric_name, value, timestamp=None, tags=[]):

tests/test_metric.py

@@ -8,6 +8,8 @@
 
 from botocore.exceptions import ClientError as BotocoreClientError
 from datadog.api.exceptions import ClientError
+
+
 from datadog_lambda.metric import lambda_metric
 from datadog_lambda.api import decrypt_kms_api_key, KMS_ENCRYPTION_CONTEXT_KEY
 from datadog_lambda.thread_stats_writer import ThreadStatsWriter
@@ -33,6 +35,17 @@ def test_lambda_metric_tagged_with_dd_lambda_layer(self):
             ]
         )
 
+    # let's fake that the extension is present, this should override DD_FLUSH_TO_LOG
+    @patch("datadog_lambda.metric.should_use_extension", True)
+    def test_lambda_metric_flush_to_log_with_extension(self):
+        os.environ["DD_FLUSH_TO_LOG"] = "True"
+        lambda_metric("test", 1)
+        expected_tag = _format_dd_lambda_layer_tag()
+        self.mock_metric_lambda_stats.distribution.assert_has_calls(
+            [call("test", 1, timestamp=None, tags=[expected_tag])]
+        )
+        del os.environ["DD_FLUSH_TO_LOG"]
+
     def test_lambda_metric_flush_to_log(self):
         os.environ["DD_FLUSH_TO_LOG"] = "True"