Files
ad-ds-simple-file-server/app/backup_to_destination.py
2026-07-17 13:23:00 +00:00

1089 lines
33 KiB
Python

#!/usr/bin/env python3
import datetime as dt
import fcntl
import os
import re
import subprocess
import sys
import tempfile
import time
from dataclasses import dataclass
from typing import Callable, Dict, List, Optional, Set, TextIO, Tuple
from urllib.parse import SplitResult, unquote, urlsplit
LOCK_PATH = "/state/backup.lock"
DEFAULT_BACKUP_LOG_FILE = "/var/log/backup.log"
DEFAULT_PROGRESS_MODE = "auto"
DEFAULT_PROGRESS_INTERVAL_SECONDS = 10
PROGRESS_BAR_WIDTH = 28
MAX_CAPTURED_OUTPUT_LINES = 50
MAX_CAPTURED_OUTPUT_RECORD_LENGTH = 1000
SNAPSHOT_NAME_RE = re.compile(r"^\d{8}T\d{6}Z$")
ANSI_ESCAPE_RE = re.compile(r"\x1b\[[0-?]*[ -/]*[@-~]")
RCLONE_FILE_PROGRESS_RE = re.compile(
r"^\s*\*\s+(?P<file>.+?):\s+(?P<percent>\d+(?:\.\d+)?)%\s*(?P<detail>.*)$"
)
RSYNC_FILE_PROGRESS_RE = re.compile(
r"^\s*[\d,.]+[A-Za-z]?\s+(?P<percent>\d+(?:\.\d+)?)%\s+(?P<detail>.+)$"
)
RSYNC_IGNORED_RECORD_PREFIXES = (
"sending incremental file list",
"receiving incremental file list",
"sent ",
"total size is ",
)
BACKUP_SOURCES: List[Tuple[str, str]] = [
("/data/private", "data/private"),
("/data/groups", "data/groups"),
("/data/fslogix", "data/fslogix"),
("/state", "state"),
("/var/lib/samba/private", "samba/private"),
]
RCLONE_SCHEME_MAP = {
"sftp": "sftp",
"smb": "smb",
"cifs": "smb",
"davfs": "webdav",
"dav": "webdav",
"webdav": "webdav",
"http": "webdav",
"https": "webdav",
}
DEFAULT_BACKUP_START_HOUR = 2
DEFAULT_RETENTION_DAILY = 3
DEFAULT_RETENTION_WEEKLY = 2
DEFAULT_RETENTION_MONTHLY = 2
DEFAULT_RETENTION_YEARLY = 1
@dataclass
class Destination:
raw_url: str
scheme: str
parts: SplitResult
username: str
password: str
hostname: str
port: Optional[int]
path: str
@dataclass
class RetentionPolicy:
daily: int
weekly: int
monthly: int
yearly: int
@dataclass(frozen=True)
class Snapshot:
name: str
timestamp: dt.datetime
@dataclass(frozen=True)
class FileProgress:
file_path: str
percent: float
detail: str
class BackupLogger:
def __init__(
self,
*,
console_stream: TextIO = sys.stdout,
error_stream: TextIO = sys.stderr,
):
self.console_stream = console_stream
self.error_stream = error_stream
self.log_path: Optional[str] = None
self._handle: Optional[TextIO] = None
def configure(self, log_path: str) -> None:
self.close()
self.log_path = log_path
if not log_path:
return
log_dir = os.path.dirname(log_path)
try:
if log_dir:
os.makedirs(log_dir, exist_ok=True)
self._handle = open(log_path, "a", encoding="utf-8")
except OSError as exc:
self._handle = None
print(
f"[backup] WARNING: unable to open log file {log_path}: {exc}",
file=self.error_stream,
flush=True,
)
def close(self) -> None:
if self._handle is None:
return
self._handle.close()
self._handle = None
def log(self, message: str, *, console: bool = True) -> None:
line = f"[backup] {message}"
if console:
print(line, file=self.console_stream, flush=True)
if self._handle is not None:
timestamp = dt.datetime.now(dt.timezone.utc).isoformat(timespec="seconds")
self._handle.write(f"{timestamp} {line}\n")
self._handle.flush()
LOGGER = BackupLogger()
def configure_logging() -> None:
LOGGER.configure(os.getenv("BACKUP_LOG_FILE", DEFAULT_BACKUP_LOG_FILE).strip())
def close_logging() -> None:
LOGGER.close()
def log(message: str, *, console: bool = True) -> None:
LOGGER.log(message, console=console)
def run_command(
command: List[str],
*,
env: Optional[Dict[str, str]] = None,
input_text: Optional[str] = None,
check: bool = True,
) -> subprocess.CompletedProcess:
result = subprocess.run(
command,
capture_output=True,
text=True,
env=env,
input=input_text,
)
if check and result.returncode != 0:
output = result.stderr.strip() or result.stdout.strip()
raise RuntimeError(f"Command failed ({command[0]}): {output}")
return result
def parse_progress_mode() -> str:
raw_value = os.getenv("BACKUP_PROGRESS", DEFAULT_PROGRESS_MODE).strip().lower()
if raw_value in {"auto", "always", "never"}:
return raw_value
log(f"Invalid BACKUP_PROGRESS='{raw_value}', using default {DEFAULT_PROGRESS_MODE}")
return DEFAULT_PROGRESS_MODE
def should_show_progress_bar(mode: str, stream: TextIO = sys.stderr) -> bool:
if mode == "always":
return True
if mode == "never":
return False
return bool(stream.isatty())
def format_percent(percent: float) -> str:
if percent.is_integer():
return str(int(percent))
return f"{percent:.1f}".rstrip("0").rstrip(".")
def clamp_percent(percent: float) -> float:
return max(0.0, min(100.0, percent))
def shorten_middle(value: str, max_length: int) -> str:
if len(value) <= max_length:
return value
if max_length <= 3:
return value[:max_length]
left = (max_length - 3) // 2
right = max_length - 3 - left
return f"{value[:left]}...{value[-right:]}"
def clean_output_record(record: str) -> str:
return ANSI_ESCAPE_RE.sub("", record).strip()
def truncate_output_record(record: str) -> str:
if len(record) <= MAX_CAPTURED_OUTPUT_RECORD_LENGTH:
return record
return f"{record[:MAX_CAPTURED_OUTPUT_RECORD_LENGTH]}..."
def parse_rclone_progress_record(record: str) -> Optional[FileProgress]:
match = RCLONE_FILE_PROGRESS_RE.match(record)
if not match:
return None
return FileProgress(
file_path=match.group("file").strip(),
percent=clamp_percent(float(match.group("percent"))),
detail=match.group("detail").strip(),
)
def rsync_file_candidate(record: str) -> Optional[str]:
stripped = record.strip()
if not stripped:
return None
lower = stripped.lower()
if any(lower.startswith(prefix) for prefix in RSYNC_IGNORED_RECORD_PREFIXES):
return None
if lower.startswith("deleting "):
return None
if stripped.endswith("/"):
return None
if RSYNC_FILE_PROGRESS_RE.match(stripped):
return None
return stripped
def parse_rsync_progress_record(
record: str, current_file: Optional[str]
) -> Optional[FileProgress]:
if not current_file:
return None
match = RSYNC_FILE_PROGRESS_RE.match(record)
if not match:
return None
return FileProgress(
file_path=current_file,
percent=clamp_percent(float(match.group("percent"))),
detail=match.group("detail").strip(),
)
class OutputRecordSplitter:
def __init__(self) -> None:
self._buffer = ""
def feed(self, chunk: str) -> List[str]:
records: List[str] = []
for char in chunk:
if char in {"\r", "\n"}:
record = clean_output_record(self._buffer)
self._buffer = ""
if record:
records.append(record)
continue
self._buffer += char
return records
def close(self) -> List[str]:
record = clean_output_record(self._buffer)
self._buffer = ""
if not record:
return []
return [record]
class SyncProgressReporter:
def __init__(
self,
backend_name: str,
source_path: str,
destination_path: str,
*,
interval_seconds: int,
interactive: bool,
stream: TextIO = sys.stderr,
now: Callable[[], float] = time.monotonic,
log_func: Callable[..., None] = log,
):
self.backend_name = backend_name
self.source_path = source_path
self.destination_path = destination_path
self.interval_seconds = interval_seconds
self.interactive = interactive
self.stream = stream
self.now = now
self.log_func = log_func
self.current_rsync_file: Optional[str] = None
self._last_log_at: Dict[str, float] = {}
self._last_logged_percent: Dict[str, float] = {}
self._last_bar_length = 0
def observe(self, record: str) -> None:
progress: Optional[FileProgress]
if self.backend_name == "rclone":
progress = parse_rclone_progress_record(record)
else:
progress = parse_rsync_progress_record(record, self.current_rsync_file)
if progress is None:
candidate = rsync_file_candidate(record)
if candidate is not None:
self.current_rsync_file = candidate
return
if progress is None:
return
self._render_bar(progress)
self._log_progress(progress)
def finish(self) -> None:
if not self.interactive or self._last_bar_length == 0:
return
self.stream.write("\r" + (" " * self._last_bar_length) + "\r")
self.stream.flush()
self._last_bar_length = 0
def _log_progress(self, progress: FileProgress) -> None:
now = self.now()
key = progress.file_path
last_log_at = self._last_log_at.get(key)
last_logged_percent = self._last_logged_percent.get(key)
is_final = progress.percent >= 100.0
if (
last_log_at is not None
and now - last_log_at < self.interval_seconds
and not (is_final and last_logged_percent != 100.0)
):
return
detail = f" ({progress.detail})" if progress.detail else ""
self.log_func(
"Upload progress "
f"{self.source_path} -> {self.destination_path}: "
f"{progress.file_path} {format_percent(progress.percent)}%{detail}",
console=not self.interactive,
)
self._last_log_at[key] = now
self._last_logged_percent[key] = progress.percent
def _render_bar(self, progress: FileProgress) -> None:
if not self.interactive:
return
filled = int(PROGRESS_BAR_WIDTH * (progress.percent / 100.0))
bar = "#" * filled + "-" * (PROGRESS_BAR_WIDTH - filled)
file_path = shorten_middle(progress.file_path, 44)
source_path = shorten_middle(self.source_path, 24)
line = (
f"[backup] {source_path}: {file_path} "
f"[{bar}] {format_percent(progress.percent)}%"
)
if len(line) >= self._last_bar_length:
padding = ""
else:
padding = " " * (self._last_bar_length - len(line))
self.stream.write(f"\r{line}{padding}")
self.stream.flush()
self._last_bar_length = len(line)
def run_streaming_command(
command: List[str],
*,
progress: SyncProgressReporter,
env: Optional[Dict[str, str]] = None,
) -> subprocess.CompletedProcess:
process = subprocess.Popen(
command,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
text=True,
bufsize=1,
env=env,
)
splitter = OutputRecordSplitter()
captured_records: List[str] = []
try:
if process.stdout is not None:
while True:
chunk = process.stdout.read(1)
if chunk == "":
if process.poll() is not None:
break
continue
for record in splitter.feed(chunk):
captured_records.append(truncate_output_record(record))
captured_records = captured_records[-MAX_CAPTURED_OUTPUT_LINES:]
progress.observe(record)
for record in splitter.close():
captured_records.append(truncate_output_record(record))
captured_records = captured_records[-MAX_CAPTURED_OUTPUT_LINES:]
progress.observe(record)
returncode = process.wait()
finally:
progress.finish()
stdout = "\n".join(captured_records)
if returncode != 0:
output = stdout.strip() or f"exit code {returncode}"
raise RuntimeError(f"Command failed ({command[0]}): {output}")
return subprocess.CompletedProcess(command, returncode, stdout=stdout, stderr="")
def parse_destination(raw_url: str) -> Destination:
parts = urlsplit(raw_url)
scheme = parts.scheme.lower()
if not scheme:
raise RuntimeError("BACKUP_DESTINATION must include a URL scheme")
hostname = parts.hostname or ""
if not hostname:
raise RuntimeError("BACKUP_DESTINATION must include a hostname")
return Destination(
raw_url=raw_url,
scheme=scheme,
parts=parts,
username=unquote(parts.username or ""),
password=unquote(parts.password or ""),
hostname=hostname,
port=parts.port,
path=unquote(parts.path or ""),
)
def redact_destination(raw_url: str) -> str:
parts = urlsplit(raw_url)
host = parts.hostname or ""
if ":" in host and not host.startswith("["):
host = f"[{host}]"
if parts.port is not None:
host = f"{host}:{parts.port}"
if parts.username:
username = unquote(parts.username)
if parts.password is not None:
auth = f"{username}:***"
else:
auth = username
netloc = f"{auth}@{host}"
else:
netloc = host
return f"{parts.scheme}://{netloc}{parts.path}"
def available_sources() -> List[Tuple[str, str]]:
sources: List[Tuple[str, str]] = []
for source_path, destination_path in BACKUP_SOURCES:
if os.path.isdir(source_path):
sources.append((source_path, destination_path))
else:
log(f"Skipping missing source: {source_path}")
return sources
def format_host(hostname: str) -> str:
if ":" in hostname and not hostname.startswith("["):
return f"[{hostname}]"
return hostname
def join_path(prefix: str, suffix: str) -> str:
left = prefix.strip("/")
right = suffix.strip("/")
if left and right:
return f"{left}/{right}"
return left or right
def parse_int_env(
name: str, default: int, *, minimum: int, maximum: Optional[int]
) -> int:
raw_value = os.getenv(name, "").strip()
if not raw_value:
return default
try:
value = int(raw_value)
except ValueError:
log(f"Invalid {name}='{raw_value}', using default {default}")
return default
if value < minimum or (maximum is not None and value > maximum):
if maximum is None:
log(f"Invalid {name}='{raw_value}', using default {default}")
else:
log(
f"Invalid {name}='{raw_value}' (expected {minimum}-{maximum}), using default {default}"
)
return default
return value
def parse_retention_policy() -> RetentionPolicy:
return RetentionPolicy(
daily=parse_int_env(
"BACKUP_RETENTION_DAILY", DEFAULT_RETENTION_DAILY, minimum=0, maximum=None
),
weekly=parse_int_env(
"BACKUP_RETENTION_WEEKLY",
DEFAULT_RETENTION_WEEKLY,
minimum=0,
maximum=None,
),
monthly=parse_int_env(
"BACKUP_RETENTION_MONTHLY",
DEFAULT_RETENTION_MONTHLY,
minimum=0,
maximum=None,
),
yearly=parse_int_env(
"BACKUP_RETENTION_YEARLY",
DEFAULT_RETENTION_YEARLY,
minimum=0,
maximum=None,
),
)
def parse_smb_identity(username: str) -> Tuple[str, str]:
if not username:
return "", ""
if ";" in username:
domain, user = username.split(";", 1)
return domain, user
if "\\" in username:
domain, user = username.split("\\", 1)
return domain, user
return "", username
def obscure_secret(secret: str) -> str:
result = run_command(["rclone", "obscure", secret])
value = result.stdout.strip()
if not value:
raise RuntimeError("rclone obscure returned an empty value")
return value
def parse_snapshot_name(name: str) -> Optional[dt.datetime]:
if not SNAPSHOT_NAME_RE.match(name):
return None
try:
parsed = dt.datetime.strptime(name, "%Y%m%dT%H%M%SZ")
except ValueError:
return None
return parsed.replace(tzinfo=dt.timezone.utc)
def choose_snapshot_name(existing_names: Set[str]) -> str:
base = dt.datetime.now(dt.timezone.utc)
for offset in range(0, 120):
candidate = (base + dt.timedelta(seconds=offset)).strftime("%Y%m%dT%H%M%SZ")
if candidate not in existing_names:
return candidate
raise RuntimeError("Unable to generate a unique snapshot name")
def is_week_start(timestamp: dt.datetime) -> bool:
return timestamp.weekday() == 0
def is_month_start(timestamp: dt.datetime) -> bool:
return timestamp.day == 1
def is_year_start(timestamp: dt.datetime) -> bool:
return timestamp.month == 1 and timestamp.day == 1
def select_newest(snapshot_pool: List[Snapshot], limit: int) -> Set[str]:
if limit <= 0:
return set()
sorted_pool = sorted(snapshot_pool, key=lambda entry: entry.timestamp, reverse=True)
return {entry.name for entry in sorted_pool[:limit]}
def compute_retained_snapshots(
snapshots: List[Snapshot], policy: RetentionPolicy
) -> Set[str]:
retained: Set[str] = set()
retained.update(select_newest(snapshots, policy.daily))
retained.update(
select_newest(
[entry for entry in snapshots if is_week_start(entry.timestamp)],
policy.weekly,
)
)
retained.update(
select_newest(
[entry for entry in snapshots if is_month_start(entry.timestamp)],
policy.monthly,
)
)
retained.update(
select_newest(
[entry for entry in snapshots if is_year_start(entry.timestamp)],
policy.yearly,
)
)
return retained
class RcloneBackend:
def __init__(self, destination: Destination):
self.base_prefix = ""
options, self.base_prefix = self._build_remote(destination)
self.config_path = self._write_config(options)
def close(self) -> None:
if os.path.exists(self.config_path):
os.remove(self.config_path)
def _run(
self,
args: List[str],
*,
check: bool = True,
input_text: Optional[str] = None,
) -> subprocess.CompletedProcess:
return run_command(
["rclone", *args, "--config", self.config_path],
check=check,
input_text=input_text,
)
def _build_remote(self, destination: Destination) -> Tuple[Dict[str, str], str]:
backend = RCLONE_SCHEME_MAP.get(destination.scheme)
if backend is None:
supported = ", ".join(["rsync", *sorted(RCLONE_SCHEME_MAP.keys())])
raise RuntimeError(
f"Unsupported BACKUP_DESTINATION scheme '{destination.scheme}'. Supported schemes: {supported}"
)
options: Dict[str, str] = {"type": backend}
remote_prefix = ""
if backend == "sftp":
options["host"] = destination.hostname
if destination.port is not None:
options["port"] = str(destination.port)
if destination.username:
options["user"] = destination.username
if destination.password:
options["pass"] = obscure_secret(destination.password)
remote_prefix = destination.path.strip("/")
return options, remote_prefix
if backend == "smb":
path_segments = [
segment for segment in destination.path.split("/") if segment
]
if not path_segments:
raise RuntimeError(
"smb destinations must include a share name in the path (example: smb://user:pass@host/share/path)"
)
share_name = path_segments[0]
remote_prefix = "/".join(path_segments[1:])
options["host"] = destination.hostname
options["share"] = share_name
if destination.port is not None:
options["port"] = str(destination.port)
domain, user = parse_smb_identity(destination.username)
if user:
options["user"] = user
if domain:
options["domain"] = domain
if destination.password:
options["pass"] = obscure_secret(destination.password)
return options, remote_prefix
webdav_scheme = (
destination.scheme if destination.scheme in {"http", "https"} else "https"
)
host = format_host(destination.hostname)
if destination.port is not None:
host = f"{host}:{destination.port}"
webdav_path = destination.path or "/"
options["url"] = f"{webdav_scheme}://{host}{webdav_path}"
options["vendor"] = "other"
if destination.username:
options["user"] = destination.username
if destination.password:
options["pass"] = obscure_secret(destination.password)
return options, remote_prefix
def _write_config(self, options: Dict[str, str]) -> str:
with tempfile.NamedTemporaryFile("w", encoding="utf-8", delete=False) as handle:
handle.write("[backup]\n")
for key, value in options.items():
handle.write(f"{key} = {value}\n")
config_path = handle.name
os.chmod(config_path, 0o600)
return config_path
def _snapshots_root(self) -> str:
return join_path(self.base_prefix, "snapshots")
def _snapshot_root(self, snapshot_name: str) -> str:
return join_path(self._snapshots_root(), snapshot_name)
def sync_source(
self,
snapshot_name: str,
source_path: str,
destination_path: str,
*,
progress_interval_seconds: int,
interactive_progress: bool,
) -> None:
remote_path = join_path(self._snapshot_root(snapshot_name), destination_path)
progress = SyncProgressReporter(
"rclone",
source_path,
destination_path,
interval_seconds=progress_interval_seconds,
interactive=interactive_progress,
)
run_streaming_command(
[
"rclone",
"sync",
f"{source_path}/",
f"backup:{remote_path}",
"--create-empty-src-dirs",
"--progress",
"--stats",
f"{progress_interval_seconds}s",
"--log-level",
"INFO",
"--config",
self.config_path,
],
progress=progress,
)
def write_marker(self, snapshot_name: str) -> None:
marker_path = join_path(self._snapshot_root(snapshot_name), ".backup_complete")
self._run(
["rcat", f"backup:{marker_path}"],
input_text=f"{dt.datetime.now(dt.timezone.utc).isoformat()}\n",
)
def _snapshot_has_marker(self, snapshot_name: str) -> bool:
result = self._run(
[
"lsf",
f"backup:{self._snapshot_root(snapshot_name)}",
"--files-only",
"--include",
".backup_complete",
],
check=False,
)
if result.returncode != 0:
return False
return any(
line.strip() == ".backup_complete" for line in result.stdout.splitlines()
)
def list_snapshots(self) -> List[str]:
result = self._run(
["lsf", f"backup:{self._snapshots_root()}", "--dirs-only", "--format", "p"],
check=False,
)
if result.returncode != 0:
output = (result.stderr.strip() or result.stdout.strip()).lower()
if "not found" in output or "doesn't exist" in output:
return []
raise RuntimeError(result.stderr.strip() or result.stdout.strip())
names: List[str] = []
for line in result.stdout.splitlines():
candidate = line.strip().rstrip("/")
if not SNAPSHOT_NAME_RE.match(candidate):
continue
if self._snapshot_has_marker(candidate):
names.append(candidate)
return sorted(set(names))
def delete_snapshot(self, snapshot_name: str) -> None:
result = self._run(
["purge", f"backup:{self._snapshot_root(snapshot_name)}"],
check=False,
)
if result.returncode != 0:
log(
f"Failed to delete snapshot {snapshot_name}: {result.stderr.strip() or result.stdout.strip()}"
)
class RsyncBackend:
def __init__(self, destination: Destination):
module_path = destination.path.lstrip("/")
if not module_path:
raise RuntimeError(
"rsync destinations must include a module path (example: rsync://user:pass@host/module/path)"
)
host = format_host(destination.hostname)
if destination.port is not None:
host = f"{host}:{destination.port}"
user_prefix = f"{destination.username}@" if destination.username else ""
self.remote_base = f"rsync://{user_prefix}{host}/{module_path.rstrip('/')}"
self.command_env = os.environ.copy()
if destination.password:
self.command_env["RSYNC_PASSWORD"] = destination.password
def close(self) -> None:
return
def _remote_path(self, path: str) -> str:
trimmed = path.strip("/")
if not trimmed:
return self.remote_base
return f"{self.remote_base}/{trimmed}"
def sync_source(
self,
snapshot_name: str,
source_path: str,
destination_path: str,
*,
progress_interval_seconds: int,
interactive_progress: bool,
) -> None:
target = self._remote_path(
join_path(f"snapshots/{snapshot_name}", destination_path)
)
progress = SyncProgressReporter(
"rsync",
source_path,
destination_path,
interval_seconds=progress_interval_seconds,
interactive=interactive_progress,
)
run_streaming_command(
[
"rsync",
"-a",
"--delete",
"--progress",
"--outbuf=L",
f"{source_path}/",
f"{target}/",
],
env=self.command_env,
progress=progress,
)
def write_marker(self, snapshot_name: str) -> None:
marker_remote = self._remote_path(f"snapshots/{snapshot_name}/.backup_complete")
marker_file = None
try:
with tempfile.NamedTemporaryFile(
"w", encoding="utf-8", delete=False
) as handle:
marker_file = handle.name
handle.write(f"{dt.datetime.now(dt.timezone.utc).isoformat()}\n")
run_command(
["rsync", "-a", marker_file, marker_remote], env=self.command_env
)
finally:
if marker_file and os.path.exists(marker_file):
os.remove(marker_file)
def _snapshot_has_marker(self, snapshot_name: str) -> bool:
marker_remote = self._remote_path(f"snapshots/{snapshot_name}/.backup_complete")
result = run_command(
["rsync", "--list-only", marker_remote],
env=self.command_env,
check=False,
)
return result.returncode == 0
def list_snapshots(self) -> List[str]:
root = self._remote_path("snapshots")
result = run_command(
["rsync", "--list-only", f"{root}/"],
env=self.command_env,
check=False,
)
if result.returncode != 0:
output = result.stderr.strip() or result.stdout.strip()
lower = output.lower()
if (
"no such file" in lower
or "not found" in lower
or "chdir failed" in lower
):
return []
raise RuntimeError(output)
names: List[str] = []
for line in result.stdout.splitlines():
line = line.strip()
if not line or line.startswith("receiving"):
continue
parts = line.split()
if not parts:
continue
candidate = parts[-1].rstrip("/")
if not SNAPSHOT_NAME_RE.match(candidate):
continue
if self._snapshot_has_marker(candidate):
names.append(candidate)
return sorted(set(names))
def delete_snapshot(self, snapshot_name: str) -> None:
snapshot_remote = self._remote_path(f"snapshots/{snapshot_name}")
empty_dir = tempfile.mkdtemp(prefix="backup-empty-")
try:
run_command(
["rsync", "-a", "--delete", f"{empty_dir}/", f"{snapshot_remote}/"],
env=self.command_env,
check=False,
)
run_command(
[
"rsync",
"-a",
"--delete",
"--prune-empty-dirs",
"--include",
f"/{snapshot_name}/***",
"--exclude",
"*",
f"{empty_dir}/",
f"{self._remote_path('snapshots')}/",
],
env=self.command_env,
check=False,
)
finally:
os.rmdir(empty_dir)
def build_backend(destination: Destination):
if destination.scheme == "rsync":
return RsyncBackend(destination)
return RcloneBackend(destination)
def parse_snapshot_inventory(snapshot_names: List[str]) -> List[Snapshot]:
snapshots: List[Snapshot] = []
for name in snapshot_names:
timestamp = parse_snapshot_name(name)
if timestamp is None:
continue
snapshots.append(Snapshot(name=name, timestamp=timestamp))
snapshots.sort(key=lambda entry: entry.timestamp, reverse=True)
return snapshots
def run_backup() -> int:
destination_url = os.getenv("BACKUP_DESTINATION", "").strip()
if not destination_url:
log("BACKUP_DESTINATION is unset, skipping backup")
return 0
policy = parse_retention_policy()
sources = available_sources()
if not sources:
log("No backup sources are available, skipping backup")
return 0
progress_interval_seconds = parse_int_env(
"BACKUP_PROGRESS_INTERVAL_SECONDS",
DEFAULT_PROGRESS_INTERVAL_SECONDS,
minimum=1,
maximum=None,
)
progress_mode = parse_progress_mode()
interactive_progress = should_show_progress_bar(progress_mode)
destination = parse_destination(destination_url)
backend = build_backend(destination)
try:
log(f"Starting backup to {redact_destination(destination.raw_url)}")
existing = set(backend.list_snapshots())
snapshot_name = choose_snapshot_name(existing)
log(f"Creating snapshot {snapshot_name}")
for source_path, destination_path in sources:
log(f"Syncing {source_path}")
backend.sync_source(
snapshot_name,
source_path,
destination_path,
progress_interval_seconds=progress_interval_seconds,
interactive_progress=interactive_progress,
)
backend.write_marker(snapshot_name)
all_snapshot_names = backend.list_snapshots()
snapshots = parse_snapshot_inventory(all_snapshot_names)
retained = compute_retained_snapshots(snapshots, policy)
deleted_count = 0
for snapshot in snapshots:
if snapshot.name in retained:
continue
log(f"Pruning snapshot {snapshot.name}")
backend.delete_snapshot(snapshot.name)
deleted_count += 1
log(
f"Backup completed (snapshots total={len(snapshots)}, retained={len(retained)}, pruned={deleted_count})"
)
return 0
finally:
backend.close()
def with_lock() -> int:
lock_dir = os.path.dirname(LOCK_PATH)
if lock_dir and not os.path.isdir(lock_dir):
os.makedirs(lock_dir, exist_ok=True)
with open(LOCK_PATH, "w", encoding="utf-8") as lock_file:
try:
fcntl.flock(lock_file, fcntl.LOCK_EX | fcntl.LOCK_NB)
except BlockingIOError:
log("Another backup process is already running; skipping this cycle")
return 0
return run_backup()
def main() -> int:
configure_logging()
try:
backup_hour = parse_int_env(
"BACKUP_START_HOUR",
DEFAULT_BACKUP_START_HOUR,
minimum=0,
maximum=23,
)
if backup_hour != DEFAULT_BACKUP_START_HOUR:
log(f"Configured backup start hour is {backup_hour}:00")
try:
return with_lock()
except Exception as exc: # pylint: disable=broad-except
log(f"ERROR: {exc}")
return 1
finally:
close_logging()
if __name__ == "__main__":
sys.exit(main())