Create backups files without having to copy inner tarballs (#110267)

homeassistant/components/backup/manager.py

@@ -4,11 +4,12 @@ from __future__ import annotations
 import asyncio
 from dataclasses import asdict, dataclass
 import hashlib
+import io
 import json
 from pathlib import Path
 import tarfile
 from tarfile import TarError
-from tempfile import TemporaryDirectory
+import time
 from typing import Any, Protocol, cast
 
 from securetar import SecureTarFile, atomic_contents_add
@@ -17,7 +18,7 @@ from homeassistant.const import __version__ as HAVERSION
 from homeassistant.core import HomeAssistant
 from homeassistant.exceptions import HomeAssistantError
 from homeassistant.helpers import integration_platform
-from homeassistant.helpers.json import save_json
+from homeassistant.helpers.json import json_bytes
 from homeassistant.util import dt as dt_util
 from homeassistant.util.json import json_loads_object
 
@@ -228,18 +229,18 @@ class BackupManager:
             LOGGER.debug("Creating backup directory")
             self.backup_dir.mkdir()
 
-        with TemporaryDirectory() as tmp_dir, SecureTarFile(
+        outer_secure_tarfile = SecureTarFile(
             tar_file_path, "w", gzip=False, bufsize=BUF_SIZE
-        ) as tar_file:
-            tmp_dir_path = Path(tmp_dir)
-            save_json(
-                tmp_dir_path.joinpath("./backup.json").as_posix(),
-                backup_data,
-            )
-            with SecureTarFile(
-                tmp_dir_path.joinpath("./homeassistant.tar.gz").as_posix(),
-                "w",
-                bufsize=BUF_SIZE,
+        )
+        with outer_secure_tarfile as outer_secure_tarfile_tarfile:
+            raw_bytes = json_bytes(backup_data)
+            fileobj = io.BytesIO(raw_bytes)
+            tar_info = tarfile.TarInfo(name="./backup.json")
+            tar_info.size = len(raw_bytes)
+            tar_info.mtime = int(time.time())
+            outer_secure_tarfile_tarfile.addfile(tar_info, fileobj=fileobj)
+            with outer_secure_tarfile.create_inner_tar(
+                "./homeassistant.tar.gz", gzip=True
             ) as core_tar:
                 atomic_contents_add(
                     tar_file=core_tar,
@@ -247,7 +248,7 @@ class BackupManager:
                     excludes=EXCLUDE_FROM_BACKUP,
                     arcname="data",
                 )
-            tar_file.add(tmp_dir_path, arcname=".")
+
         return tar_file_path.stat().st_size
 
 

tests/components/backup/test_manager.py

@@ -29,11 +29,11 @@ async def _mock_backup_generation(manager: BackupManager):
             Path(".storage"),
         ]
 
-    with patch("tarfile.open", MagicMock()) as mocked_tarfile, patch(
-        "pathlib.Path.iterdir", _mock_iterdir
-    ), patch("pathlib.Path.stat", MagicMock(st_size=123)), patch(
-        "pathlib.Path.is_file", lambda x: x.name != ".storage"
-    ), patch(
+    with patch(
+        "homeassistant.components.backup.manager.SecureTarFile"
+    ) as mocked_tarfile, patch("pathlib.Path.iterdir", _mock_iterdir), patch(
+        "pathlib.Path.stat", MagicMock(st_size=123)
+    ), patch("pathlib.Path.is_file", lambda x: x.name != ".storage"), patch(
         "pathlib.Path.is_dir",
         lambda x: x.name == ".storage",
     ), patch(
@@ -46,21 +46,20 @@ async def _mock_backup_generation(manager: BackupManager):
         "pathlib.Path.mkdir",
         MagicMock(),
     ), patch(
-        "homeassistant.components.backup.manager.save_json"
-    ) as mocked_save_json, patch(
+        "homeassistant.components.backup.manager.json_bytes",
+        return_value=b"{}",  # Empty JSON
+    ) as mocked_json_bytes, patch(
         "homeassistant.components.backup.manager.HAVERSION",
         "2025.1.0",
     ):
         await manager.generate_backup()
 
-        assert mocked_save_json.call_count == 1
-        assert mocked_save_json.call_args[0][1]["homeassistant"] == {
-            "version": "2025.1.0"
-        }
-
-        assert (
-            manager.backup_dir.as_posix()
-            in mocked_tarfile.call_args_list[0].kwargs["name"]
+        assert mocked_json_bytes.call_count == 1
+        backup_json_dict = mocked_json_bytes.call_args[0][0]
+        assert isinstance(backup_json_dict, dict)
+        assert backup_json_dict["homeassistant"] == {"version": "2025.1.0"}
+        assert manager.backup_dir.as_posix() in str(
+            mocked_tarfile.call_args_list[0][0][0]
         )