Add test for the use of the 'vertex_ai' system, and improve how this system is determined.

Author: michaelsafyan

instrumentation-genai/opentelemetry-instrumentation-google-genai/src/opentelemetry/instrumentation/google_genai/generate_content.py

@@ -91,12 +91,25 @@ def _guess_genai_system_from_env():
     return _get_gemini_system_name()
 
 
+def _get_is_vertexai(models_object: Union[Models, AsyncModels]):
+    # Since commit 8e561de04965bb8766db87ad8eea7c57c1040442 of "googleapis/python-genai",
+    # it is possible to obtain the information using a documented property.
+    if hasattr(models_object, 'vertexai'):
+        vertexai_attr = getattr(models_object, 'vertexai')
+        if vertexai_attr is not None:
+            return vertexai_attr
+    # For earlier revisions, it is necessary to deeply inspect the internals.
+    if hasattr(models_object, '_api_client'):
+        client = getattr(models_object, "_api_client")
+        if not client:
+            return None
+        if hasattr(client, 'vertexai'):
+            return getattr(client, "vertexai")
+    return None
+
 
 def _determine_genai_system(models_object: Union[Models, AsyncModels]):
-    client = getattr(models_object, "_api_client")
-    if not client:
-        return _guess_genai_system_from_env()
-    vertexai_attr = getattr(client, "vertexai")
+    vertexai_attr = _get_is_vertexai(models_object)
     if vertexai_attr is None:
         return _guess_genai_system_from_env()
     if vertexai_attr:

instrumentation-genai/opentelemetry-instrumentation-google-genai/tests/generate_content/test_sync_nonstreaming.py

@@ -75,6 +75,17 @@ def test_generated_span_has_minimal_genai_attributes(self):
         self.assertEqual(span.attributes["gen_ai.system"], "gemini")
         self.assertEqual(span.attributes["gen_ai.operation.name"], "GenerateContent")
 
+    def test_generated_span_has_vertex_ai_system_when_configured(self):
+        self.set_use_vertex(True)
+        self.configure_valid_response(response_text="Yep, it works!")
+        self.generate_content(
+            model="gemini-2.0-flash",
+            contents="Does this work?")
+        self.otel.assert_has_span_named("google.genai.Models.generate_content")
+        span = self.otel.get_span_named("google.genai.Models.generate_content")
+        self.assertEqual(span.attributes["gen_ai.system"], "vertex_ai")
+        self.assertEqual(span.attributes["gen_ai.operation.name"], "GenerateContent")
+
     def test_generated_span_counts_tokens(self):
         self.configure_valid_response(input_tokens=123, output_tokens=456)
         self.generate_content(