Support HOT/COLD snapshots for Add-ons (#2943)

* Support HOT/COLD snapshots for Add-ons

* Apply suggestions from code review

Co-authored-by: Joakim Sørensen <joasoe@gmail.com>

* Add warning

Co-authored-by: Joakim Sørensen <joasoe@gmail.com>

supervisor/addons/addon.py

@@ -65,6 +65,7 @@ from ..utils import check_port
 from ..utils.apparmor import adjust_profile
 from ..utils.json import read_json_file, write_json_file
 from ..utils.tar import atomic_contents_add, secure_path
+from .const import SnapshotAddonMode
 from .model import AddonModel, Data
 from .options import AddonOptions
 from .utils import remove_data
@@ -695,6 +696,8 @@ class Addon(AddonModel):
 
     async def snapshot(self, tar_file: tarfile.TarFile) -> None:
         """Snapshot state of an add-on."""
+        is_running = await self.is_running()
+
         with TemporaryDirectory(dir=self.sys_config.path_tmp) as temp:
             temp_path = Path(temp)
 
@@ -744,8 +747,15 @@ class Addon(AddonModel):
                         arcname="data",
                     )
 
-            if self.snapshot_pre is not None:
+            if (
+                is_running
+                and self.snapshot_mode == SnapshotAddonMode.HOT
+                and self.snapshot_pre is not None
+            ):
                 await self._snapshot_command(self.snapshot_pre)
+            elif is_running and self.snapshot_mode == SnapshotAddonMode.COLD:
+                _LOGGER.info("Shutdown add-on %s for cold snapshot", self.slug)
+                await self.instance.stop()
 
             try:
                 _LOGGER.info("Building snapshot for add-on %s", self.slug)
@@ -754,8 +764,15 @@ class Addon(AddonModel):
                 _LOGGER.error("Can't write tarfile %s: %s", tar_file, err)
                 raise AddonsError() from err
             finally:
-                if self.snapshot_post is not None:
+                if (
+                    is_running
+                    and self.snapshot_mode == SnapshotAddonMode.HOT
+                    and self.snapshot_post is not None
+                ):
                     await self._snapshot_command(self.snapshot_post)
+                elif is_running and self.snapshot_mode is SnapshotAddonMode.COLD:
+                    _LOGGER.info("Starting add-on %s again", self.slug)
+                    await self.start()
 
         _LOGGER.info("Finish snapshot for addon %s", self.slug)
 

supervisor/addons/const.py

@@ -0,0 +1,12 @@
+"""Add-on static data."""
+from enum import Enum
+
+
+class SnapshotAddonMode(str, Enum):
+    """Snapshot mode of an Add-on."""
+
+    HOT = "hot"
+    COLD = "cold"
+
+
+ATTR_SNAPSHOT = "snapshot"

supervisor/addons/model.py

@@ -5,6 +5,8 @@ from typing import Any, Awaitable, Dict, List, Optional
 
 from awesomeversion import AwesomeVersion, AwesomeVersionException
 
+from supervisor.addons.const import SnapshotAddonMode
+
 from ..const import (
     ATTR_ADVANCED,
     ATTR_APPARMOR,
@@ -76,6 +78,7 @@ from ..const import (
 )
 from ..coresys import CoreSys, CoreSysAttributes
 from ..docker.const import Capabilities
+from .const import ATTR_SNAPSHOT
 from .options import AddonOptions, UiOptions
 from .validate import RE_SERVICE, RE_VOLUME
 
@@ -370,6 +373,11 @@ class AddonModel(CoreSysAttributes, ABC):
         """Return post-snapshot command."""
         return self.data.get(ATTR_SNAPSHOT_POST)
 
+    @property
+    def snapshot_mode(self) -> SnapshotAddonMode:
+        """Return if snapshot is hot/cold."""
+        return self.data[ATTR_SNAPSHOT]
+
     @property
     def default_init(self) -> bool:
         """Return True if the add-on have no own init."""

supervisor/addons/validate.py

@@ -7,6 +7,8 @@ import uuid
 
 import voluptuous as vol
 
+from supervisor.addons.const import SnapshotAddonMode
+
 from ..const import (
     ARCH_ALL,
     ATTR_ACCESS_TOKEN,
@@ -107,6 +109,7 @@ from ..validate import (
     uuid_match,
     version_tag,
 )
+from .const import ATTR_SNAPSHOT
 from .options import RE_SCHEMA_ELEMENT
 
 _LOGGER: logging.Logger = logging.getLogger(__name__)
@@ -161,6 +164,14 @@ def _warn_addon_config(config: Dict[str, Any]):
             name,
         )
 
+    if config.get(ATTR_SNAPSHOT, SnapshotAddonMode.HOT) == SnapshotAddonMode.COLD and (
+        config.get(ATTR_SNAPSHOT_POST) or config.get(ATTR_SNAPSHOT_PRE)
+    ):
+        _LOGGER.warning(
+            "Add-on which only support COLD backups trying to use post/pre commands. Please report this to the maintainer of %s",
+            name,
+        )
+
     return config
 
 
@@ -284,6 +295,9 @@ _SCHEMA_ADDON_CONFIG = vol.Schema(
         vol.Optional(ATTR_SNAPSHOT_EXCLUDE): [str],
         vol.Optional(ATTR_SNAPSHOT_PRE): str,
         vol.Optional(ATTR_SNAPSHOT_POST): str,
+        vol.Optional(ATTR_SNAPSHOT, default=SnapshotAddonMode.HOT): vol.Coerce(
+            SnapshotAddonMode
+        ),
         vol.Optional(ATTR_OPTIONS, default={}): dict,
         vol.Optional(ATTR_SCHEMA, default={}): vol.Any(
             vol.Schema(