fix(sdk): preserve unavailable error details (#4534)

Co-authored-by: hylin <linhongyu510@users.noreply.github.com>

Author: linhongyu510

sdk/python/openviking_sdk/client.py

@@ -662,6 +662,10 @@ def _raise_exception(self, error: Dict[str, Any]) -> None:
             resource = details.get("resource", "") if details else ""
             resource_type = details.get("type", "resource") if details else "resource"
             raise exc_class(resource, resource_type)
+        if exc_class == UnavailableError:
+            service = details.get("service", "service") if details else "service"
+            reason = details.get("reason", "") if details else message
+            raise exc_class(service, reason)
         raise exc_class(message)
 
     def _zip_directory(self, dir_path: str) -> str:

sdk/python/tests/test_error_mapping.py

@@ -5,6 +5,7 @@
     ConflictError,
     OpenVikingError,
     ResourceExhaustedError,
+    UnavailableError,
     UnimplementedError,
 )
 
@@ -41,3 +42,27 @@ def test_client_preserves_unknown_error_code():
 
     assert exc_info.value.code == "PROVIDER_SPECIFIC"
     assert exc_info.value.details == {"x": 1}
+
+
+def test_client_preserves_unavailable_service_and_reason():
+    client = AsyncHTTPClient(url="http://127.0.0.1:1933")
+
+    with pytest.raises(UnavailableError) as exc_info:
+        client._raise_exception(
+            {
+                "code": "UNAVAILABLE",
+                "message": "Storage backend unavailable: lock contention",
+                "details": {
+                    "service": "storage backend",
+                    "reason": "failed to read lock token (os error 33)",
+                },
+            }
+        )
+
+    assert str(exc_info.value) == (
+        "Storage backend unavailable: failed to read lock token (os error 33)"
+    )
+    assert exc_info.value.details == {
+        "service": "storage backend",
+        "reason": "failed to read lock token (os error 33)",
+    }