(Feat) datadog_llm_observability callback - emit request_tags on logs (#7883)

* dd - emit tags on llm obs payload

* dd  - show requester tags on traces

* test_get_datadog_tags

* _get_datadog_tags

* fix dd POD_NAME

* test_get_datadog_tags

tests/logging_callback_tests/test_datadog.py

@@ -532,3 +532,48 @@ async def test_datadog_non_serializable_messages():
     # Check that the non-serializable objects were converted to strings
     assert isinstance(dict_payload["messages"][0]["content"], str)
     assert isinstance(dict_payload["response"]["choices"][0]["message"]["content"], str)
+
+
+def test_get_datadog_tags():
+    """Test the _get_datadog_tags static method with various inputs"""
+    # Test with no standard_logging_object and default env vars
+    base_tags = DataDogLogger._get_datadog_tags()
+    assert "env:" in base_tags
+    assert "service:" in base_tags
+    assert "version:" in base_tags
+    assert "POD_NAME:" in base_tags
+    assert "HOSTNAME:" in base_tags
+
+    # Test with custom env vars
+    test_env = {
+        "DD_ENV": "production",
+        "DD_SERVICE": "custom-service",
+        "DD_VERSION": "1.0.0",
+        "HOSTNAME": "test-host",
+        "POD_NAME": "pod-123",
+    }
+    with patch.dict(os.environ, test_env):
+        custom_tags = DataDogLogger._get_datadog_tags()
+        assert "env:production" in custom_tags
+        assert "service:custom-service" in custom_tags
+        assert "version:1.0.0" in custom_tags
+        assert "HOSTNAME:test-host" in custom_tags
+        assert "POD_NAME:pod-123" in custom_tags
+
+    # Test with standard_logging_object containing request_tags
+    standard_logging_obj = create_standard_logging_payload()
+    standard_logging_obj["request_tags"] = ["tag1", "tag2"]
+
+    tags_with_request = DataDogLogger._get_datadog_tags(standard_logging_obj)
+    assert "request_tag:tag1" in tags_with_request
+    assert "request_tag:tag2" in tags_with_request
+
+    # Test with empty request_tags
+    standard_logging_obj["request_tags"] = []
+    tags_empty_request = DataDogLogger._get_datadog_tags(standard_logging_obj)
+    assert "request_tag:" not in tags_empty_request
+
+    # Test with None request_tags
+    standard_logging_obj["request_tags"] = None
+    tags_none_request = DataDogLogger._get_datadog_tags(standard_logging_obj)
+    assert "request_tag:" not in tags_none_request