Add default and service name to get_aggregated_resource

opentelemetry-sdk/src/opentelemetry/sdk/resources/__init__.py

@@ -163,22 +163,11 @@ def create(
         Returns:
             The newly-created Resource.
         """
+
         if not attributes:
             attributes = {}
-        resource = _DEFAULT_RESOURCE.merge(
-            OTELResourceDetector().detect()
-        ).merge(Resource(attributes, schema_url))
-        if not resource.attributes.get(SERVICE_NAME, None):
-            default_service_name = "unknown_service"
-            process_executable_name = resource.attributes.get(
-                PROCESS_EXECUTABLE_NAME, None
-            )
-            if process_executable_name:
-                default_service_name += ":" + process_executable_name
-            resource = resource.merge(
-                Resource({SERVICE_NAME: default_service_name}, schema_url)
-            )
-        return resource
+
+        return get_aggregated_resources([], Resource(attributes, schema_url))
 
     @staticmethod
     def get_empty() -> "Resource":
@@ -276,7 +265,8 @@ def detect(self) -> "Resource":
         service_name = os.environ.get(OTEL_SERVICE_NAME)
         if service_name:
             env_resource_map[SERVICE_NAME] = service_name
-        return Resource(env_resource_map)
+
+        return _DEFAULT_RESOURCE.merge(Resource(env_resource_map))
 
 
 def get_aggregated_resources(
@@ -292,7 +282,7 @@ def get_aggregated_resources(
     :return:
     """
     final_resource = initial_resource or _EMPTY_RESOURCE
-    detectors = [OTELResourceDetector()] + detectors
+    detectors = [OTELResourceDetector] + detectors
 
     with concurrent.futures.ThreadPoolExecutor(max_workers=4) as executor:
         futures = [executor.submit(detector.detect) for detector in detectors]
@@ -310,4 +300,21 @@ def get_aggregated_resources(
                 detected_resources = _EMPTY_RESOURCE
             finally:
                 final_resource = final_resource.merge(detected_resources)
-    return final_resource
+
+    if final_resource.attributes.get(SERVICE_NAME):
+        return final_resource
+
+    default_service_name = "unknown_service"
+
+    process_executable_name = final_resource.attributes.get(
+        PROCESS_EXECUTABLE_NAME
+    )
+
+    if process_executable_name:
+        default_service_name = (
+            "%s:%s",
+            default_service_name,
+            process_executable_name,
+        )
+
+    return final_resource.merge(Resource({SERVICE_NAME: default_service_name}))