Notify HA Core when backup is being executed (#3305)

* Notify HA Core when backup is being executed

Notify Home Assistant Core using the Websocket API when the Home Assistant
config directory is about to get backed up. This makes sure the Core can
prepare the SQLite database (if active) so it safe to make a backup.

* Only close WebSocket connection on connection errors

Let regular WebSocket errors bubble to the caller so they can be handled
explicitly.

* Add version restriction to backup/start/end WS commands

* Restore Home Assistant metadata when Home Assistant is selected

supervisor/homeassistant/module.py

@@ -4,11 +4,16 @@ from ipaddress import IPv4Address
 import logging
 from pathlib import Path
 import shutil
+import tarfile
 from typing import Optional
 from uuid import UUID
 
 from awesomeversion import AwesomeVersion, AwesomeVersionException
 
+from supervisor.exceptions import HomeAssistantWSError
+from supervisor.homeassistant.const import WSType
+from supervisor.utils.tar import SecureTarFile, atomic_contents_add
+
 from ..const import (
     ATTR_ACCESS_TOKEN,
     ATTR_AUDIO_INPUT,
@@ -24,6 +29,7 @@ from ..const import (
     ATTR_WAIT_BOOT,
     ATTR_WATCHDOG,
     FILE_HASSIO_HOMEASSISTANT,
+    FOLDER_HOMEASSISTANT,
     BusEvent,
 )
 from ..coresys import CoreSys, CoreSysAttributes
@@ -39,6 +45,15 @@ from .websocket import HomeAssistantWebSocket
 _LOGGER: logging.Logger = logging.getLogger(__name__)
 
 
+HOMEASSISTANT_BACKUP_EXCLUDE = [
+    "*.db-shm",
+    "__pycache__/*",
+    "*.log",
+    "*.log.*",
+    "OZW_Log.txt",
+]
+
+
 class HomeAssistant(FileConfiguration, CoreSysAttributes):
     """Home Assistant core object for handle it."""
 
@@ -284,3 +299,59 @@ class HomeAssistant(FileConfiguration, CoreSysAttributes):
             return
 
         self.sys_homeassistant.websocket.send_message({ATTR_TYPE: "usb/scan"})
+
+    async def backup(self, secure_tar_file: SecureTarFile) -> None:
+        """Backup Home Assistant Core config/ directory."""
+
+        # Let Home Assistant Core know we are about to backup
+        try:
+            await self.websocket.async_send_command({ATTR_TYPE: WSType.BACKUP_START})
+
+        except HomeAssistantWSError:
+            _LOGGER.warning(
+                "Preparing backup of Home Assistant Core failed. Check HA Core logs."
+            )
+
+        def _write_tarfile():
+            with secure_tar_file as tar_file:
+                # Backup system
+                origin_dir = Path(self.sys_config.path_supervisor, FOLDER_HOMEASSISTANT)
+
+                # Backup data
+                atomic_contents_add(
+                    tar_file,
+                    origin_dir,
+                    excludes=HOMEASSISTANT_BACKUP_EXCLUDE,
+                    arcname=".",
+                )
+
+        try:
+            _LOGGER.info("Backing up Home Assistant Core config folder")
+            await self.sys_run_in_executor(_write_tarfile)
+            _LOGGER.info("Backup Home Assistant Core config folder done")
+        finally:
+            try:
+                await self.sys_homeassistant.websocket.async_send_command(
+                    {ATTR_TYPE: WSType.BACKUP_END}
+                )
+            except HomeAssistantWSError:
+                _LOGGER.warning(
+                    "Error during Home Assistant Core backup. Check HA Core logs."
+                )
+
+    async def restore(self, secure_tar_file: SecureTarFile) -> None:
+        """Restore Home Assistant Core config/ directory."""
+
+        # Perform a restore
+        def _restore_tarfile():
+            origin_dir = Path(self.sys_config.path_supervisor, FOLDER_HOMEASSISTANT)
+
+            with secure_tar_file as tar_file:
+                tar_file.extractall(path=origin_dir, members=tar_file)
+
+        try:
+            _LOGGER.info("Restore Home Assistant Core config folder")
+            await self.sys_run_in_executor(_restore_tarfile)
+            _LOGGER.info("Restore Home Assistant Core config folder done")
+        except (tarfile.TarError, OSError) as err:
+            _LOGGER.warning("Can't restore Home Assistant Core config folder: %s", err)