Files
bambuddy/backend/app/services/local_backup.py
T
maziggy a1cb5d5b4d fix(backup): interpret scheduled-backup HH:MM as local time, not UTC (#1602 follow-up)
The Scheduled Local Backups time-of-day picker was interpreted as UTC by
  _calculate_next_run, so a UTC+3 user had to enter 18:00 to get a 21:00
  local backup. The UI labeled the field "UTC" but it was still surprising.

  Picker is now interpreted in the container's local timezone, resolved
  from the TZ env var via zoneinfo.ZoneInfo (same source the Support page's
  environment.timezone shows). UTC fallback when TZ is unset or
  unrecognised. The /local-backup/status endpoint exposes the resolved
  zone, and the UI renders it next to the field via a new
  backup.localTimeHint i18n key with real translations in all 10
  non-English locales.

  One-time behaviour change for users who entered a UTC time as a
  workaround: the first scheduled cycle after upgrade will run at their
  local TZ offset earlier than expected. Re-enter the time as local once
  and it is correct from then on. No migration is shipped; migrating
  around a DST boundary would be ambiguous.
2026-06-04 10:17:10 +02:00

303 lines
12 KiB
Python

"""Scheduled local backup service.
Creates ZIP snapshots of the full Bambuddy data (database + data directories)
on a configurable schedule with retention management.
"""
import asyncio
import logging
import os
from datetime import datetime, timedelta, timezone
from pathlib import Path
from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
from sqlalchemy import select
from backend.app.core.config import settings as app_settings
from backend.app.core.database import async_session
from backend.app.models.settings import Settings
logger = logging.getLogger(__name__)
def _local_zone() -> ZoneInfo:
"""Resolve the local timezone for scheduled-backup HH:MM interpretation.
Uses the container's ``TZ`` env var (the same value the support package
surfaces); falls back to UTC when unset or unrecognised so a missing TZ
keeps the legacy behaviour rather than crashing. See #1602 follow-up.
"""
tz_name = os.environ.get("TZ", "").strip()
if not tz_name:
return ZoneInfo("UTC")
try:
return ZoneInfo(tz_name)
except ZoneInfoNotFoundError:
logger.warning("Unrecognised TZ env value %r, scheduling in UTC", tz_name)
return ZoneInfo("UTC")
SCHEDULE_INTERVALS = {
"hourly": 3600,
"daily": 86400,
"weekly": 604800,
}
def _default_backup_dir() -> Path:
return app_settings.base_dir / "backups"
class LocalBackupService:
"""Manages scheduled local backup snapshots with retention."""
def __init__(self):
self._scheduler_task: asyncio.Task | None = None
self._check_interval = 60
self._running: bool = False
self._last_backup_at: str | None = None
self._last_status: str | None = None
self._last_message: str | None = None
self._next_run: datetime | None = None
async def start_scheduler(self):
"""Start the background scheduler loop."""
if self._scheduler_task is not None:
return
logger.info("Starting local backup scheduler")
# Seed next_run from settings so the first check has a target
await self._seed_next_run()
self._scheduler_task = asyncio.create_task(self._scheduler_loop())
def stop_scheduler(self):
"""Stop the scheduler."""
if self._scheduler_task:
self._scheduler_task.cancel()
self._scheduler_task = None
logger.info("Stopped local backup scheduler")
async def _scheduler_loop(self):
"""Main scheduler loop — checks for due backups every minute."""
while True:
try:
await asyncio.sleep(self._check_interval)
await self._check_scheduled_backup()
except asyncio.CancelledError:
break
except Exception as e:
logger.error("Error in local backup scheduler: %s", e)
await asyncio.sleep(60)
async def _seed_next_run(self):
"""Load settings and calculate initial next_run."""
try:
settings = await self._load_settings()
if settings.get("enabled"):
self._next_run = self._calculate_next_run(
settings.get("schedule", "daily"),
settings.get("time", "03:00"),
)
except Exception as e:
logger.debug("Could not seed local backup next_run: %s", e)
async def _load_settings(self) -> dict:
"""Read local backup settings from the DB."""
async with async_session() as db:
keys = [
"local_backup_enabled",
"local_backup_schedule",
"local_backup_time",
"local_backup_retention",
"local_backup_path",
]
result = await db.execute(select(Settings).where(Settings.key.in_(keys)))
rows = {r.key: r.value for r in result.scalars().all()}
return {
"enabled": rows.get("local_backup_enabled", "false").lower() == "true",
"schedule": rows.get("local_backup_schedule", "daily"),
"time": rows.get("local_backup_time", "03:00"),
"retention": int(rows.get("local_backup_retention", "5")),
"path": rows.get("local_backup_path", ""),
}
async def _check_scheduled_backup(self):
"""Check if a scheduled backup is due and run it."""
settings = await self._load_settings()
if not settings["enabled"]:
self._next_run = None
return
now = datetime.now(timezone.utc)
# If no next_run set, schedule one
if self._next_run is None:
self._next_run = self._calculate_next_run(settings["schedule"], settings["time"])
return
if self._next_run <= now:
logger.info("Running scheduled local backup")
await self.run_backup(settings)
self._next_run = self._calculate_next_run(settings["schedule"], settings["time"])
def _calculate_next_run(self, schedule_type: str, time_str: str = "03:00") -> datetime:
"""Calculate the next scheduled run time.
For hourly: next full hour (timezone-agnostic).
For daily/weekly: next occurrence of the configured HH:MM, interpreted
in the container's local timezone (TZ env var, UTC fallback). Returns
a UTC-aware datetime for storage / comparison against ``now``.
"""
now_utc = datetime.now(timezone.utc)
if schedule_type == "hourly":
# Next full hour
next_run = now_utc.replace(minute=0, second=0, microsecond=0) + timedelta(hours=1)
return next_run
# Parse HH:MM time
try:
parts = time_str.strip().split(":")
hour = int(parts[0])
minute = int(parts[1]) if len(parts) > 1 else 0
except (ValueError, IndexError):
hour, minute = 3, 0
local_tz = _local_zone()
now_local = now_utc.astimezone(local_tz)
# Next occurrence of HH:MM local time, today or tomorrow.
# ``fold=0`` resolves the ambiguous wall-clock window at DST fall-back
# to the earlier instance (consistent with cron's behaviour). On the
# spring-forward gap the synthesized local time will normalise to the
# next valid instant when converted to UTC.
next_local = now_local.replace(hour=hour, minute=minute, second=0, microsecond=0, fold=0)
if next_local <= now_local:
next_local += timedelta(days=1)
if schedule_type == "weekly":
next_local += timedelta(weeks=1)
return next_local.astimezone(timezone.utc)
def _resolve_backup_dir(self, path_setting: str) -> Path:
"""Resolve the backup output directory from settings."""
if path_setting.strip():
return Path(path_setting.strip())
return _default_backup_dir()
async def run_backup(self, settings: dict | None = None) -> dict:
"""Run a backup now. Returns {success, message, filename}."""
if self._running:
return {"success": False, "message": "Backup already in progress"}
self._running = True
try:
if settings is None:
settings = await self._load_settings()
backup_dir = self._resolve_backup_dir(settings["path"])
backup_dir.mkdir(parents=True, exist_ok=True)
from backend.app.api.routes.settings import create_backup_zip
zip_path, filename = await create_backup_zip(output_path=backup_dir)
# Prune old backups
retention = max(1, settings["retention"])
self._prune_backups(backup_dir, retention)
self._last_backup_at = datetime.now(timezone.utc).isoformat()
self._last_status = "success"
self._last_message = filename
logger.info("Local backup created: %s", zip_path)
return {"success": True, "message": "Backup created", "filename": filename}
except Exception as e:
self._last_backup_at = datetime.now(timezone.utc).isoformat()
self._last_status = "failed"
self._last_message = str(e)
logger.error("Local backup failed: %s", e, exc_info=True)
return {"success": False, "message": f"Backup failed: {e}"}
finally:
self._running = False
def _prune_backups(self, backup_dir: Path, retention: int):
"""Delete oldest backups exceeding the retention count."""
backups = sorted(
backup_dir.glob("bambuddy-backup-*.zip"),
key=lambda p: p.stat().st_mtime,
reverse=True,
)
for old_backup in backups[retention:]:
try:
old_backup.unlink()
logger.info("Pruned old backup: %s", old_backup.name)
except OSError as e:
logger.warning("Could not delete old backup %s: %s", old_backup.name, e)
def get_status(self) -> dict:
"""Return current scheduler status."""
return {
"is_running": self._running,
"last_backup_at": self._last_backup_at,
"last_status": self._last_status,
"last_message": self._last_message,
"next_run": self._next_run.isoformat() if self._next_run else None,
}
def resolve_backup_file(self, path_setting: str, filename: str) -> Path | None:
"""Resolve a backup filename to a full path, with safety checks."""
if "/" in filename or "\\" in filename or ".." in filename:
return None
if not filename.startswith("bambuddy-backup-") or not filename.endswith(".zip"):
return None
backup_dir = self._resolve_backup_dir(path_setting)
target = (
backup_dir / filename
) # SEC-PATH-OK: filename rejected above on /, \\, .., plus startswith "bambuddy-backup-" + endswith ".zip" gate
if not target.exists():
return None
return target
def list_backups(self, path_setting: str) -> list[dict]:
"""List backup ZIP files in the backup directory."""
backup_dir = self._resolve_backup_dir(path_setting)
if not backup_dir.exists():
return []
backups = []
for f in sorted(backup_dir.glob("bambuddy-backup-*.zip"), key=lambda p: p.stat().st_mtime, reverse=True):
stat = f.stat()
backups.append(
{
"filename": f.name,
"size": stat.st_size,
"created_at": datetime.fromtimestamp(stat.st_mtime, tz=timezone.utc).isoformat(),
}
)
return backups
def delete_backup(self, path_setting: str, filename: str) -> dict:
"""Delete a specific backup file. Returns {success, message}."""
# Path traversal protection
if "/" in filename or "\\" in filename or ".." in filename:
return {"success": False, "message": "Invalid filename"}
backup_dir = self._resolve_backup_dir(path_setting)
target = (
backup_dir / filename
) # SEC-PATH-OK: filename rejected above on /, \\, .., plus startswith "bambuddy-backup-" + endswith ".zip" gate below
if not target.exists():
return {"success": False, "message": "Backup not found"}
if not target.name.startswith("bambuddy-backup-") or not target.name.endswith(".zip"):
return {"success": False, "message": "Invalid backup file"}
try:
target.unlink()
return {"success": True, "message": "Backup deleted"}
except OSError as e:
return {"success": False, "message": f"Could not delete: {e}"}
local_backup_service = LocalBackupService()