"""Stack backup & restore — compose files, bind-mount data and named volumes. A backup is a single ``.tar.gz`` with this layout:: manifest.json metadata + full inventory of what was captured compose/... the stack directory as StackPilot can see it binds/.tar contents of each captured bind-mount source volumes/.tar contents of each captured named volume Bind sources and volumes are read/written through a throwaway helper container (see :mod:`services.stack_assets_service`) so that host paths this container cannot see are still captured — without that, a stack whose data directories live outside StackPilot's own mount would back up as "just the compose file". What makes a backup and its restore trustworthy, and what this module keeps to: * **Consistent.** Whenever data is captured — including data folders that ride along inside the stack directory — the stack's running containers are stopped first and exactly those are started again afterwards. A stack that cannot be stopped is not backed up half-written. The stack is locked for the duration, so a deploy, update or second backup cannot interleave. * **Nothing is lost that the backup does not contain.** A restore replaces what the backup holds and leaves alone what it does not: folders left out (too large, deselected, remote storage) and anything mounted into the stack directory from another filesystem survive an overwrite. * **Verified before destructive.** The whole archive is read once before a restore touches anything, and the stack directory is unpacked next to the old one first. * **A restore under a new name never writes into the original's data**: folders outside the stack directory and volumes not named after the stack are skipped rather than overwritten. * **Remote storage** (NFS/CIFS/...) is neither archived nor wiped. """ from __future__ import annotations import asyncio import io import json import logging import os import re import shutil import stat import tarfile import tempfile import zlib from contextlib import contextmanager from datetime import timedelta from typing import Optional from sqlmodel import Session from database import engine from docker_client import DockerError, get_long_client, safe_call from services import ( compose_service, stack_job_service, stack_lock_service, stack_assets_service as assets, ) logger = logging.getLogger("stackpilot.backup") COMPOSE_PROJECT_LABEL = assets.COMPOSE_PROJECT_LABEL COMPOSE_VOLUME_LABEL = assets.COMPOSE_VOLUME_LABEL MANIFEST_NAME = "manifest.json" #: 3 added compose_binds/excluded (what the compose/ tree does and does not #: carry) and each volume's driver/options/external. Older ones restore too. BACKUP_FORMAT_VERSION = 3 #: How long a backup or restore may hold the stack lock before another #: operation may take it over. Generous: a large volume can take hours. LOCK_TTL = timedelta(hours=12) class BackupError(Exception): pass class StackBusyError(BackupError): """The stack is locked by another operation (deploy, update, backup).""" class BackupCancelled(BackupError): """Somebody stopped this backup from the outside. Not a failure: the archive is thrown away, the stack is started again and the lock goes, exactly as after an error — but nothing is reported as broken and no "backup failed" notification goes out. """ # --------------------------------------------------------------------------- # # Backup filename convention # --------------------------------------------------------------------------- # def backup_basename(stack_id: str, prefix: Optional[str] = None) -> str: """Filename stem used to group a stack's backups (and match for retention). ``prefix`` (e.g. a remote host slug) keeps backups of same-named stacks on different hosts from colliding / pruning each other on a shared destination. """ return f"backup-{prefix}-{stack_id}" if prefix else f"backup-{stack_id}" def backup_filename( stack_id: str, include_volumes: bool, prefix: Optional[str] = None, tz: Optional[str] = None, ) -> str: """``backup---YYYYmmdd-HHMMSS.tar.gz``, the time on the wall clock of ``tz`` — the schedule's zone, or the browser's for a backup made by hand. It used to be UTC, so a backup taken at 12:21 in Berlin was called …-102154 and seemed to be from two hours earlier. The format is unchanged, so retention still matches older files (it orders by mtime).""" from services.schedule_service import zone date = compose_service.now().astimezone(zone(tz)).strftime("%Y%m%d-%H%M%S") suffix = "full" if include_volumes else "config" return f"{backup_basename(stack_id, prefix)}-{suffix}-{date}.tar.gz" def backup_name_pattern(stack_id: str, prefix: Optional[str] = None) -> re.Pattern: """Matches exactly this stack's backup files. A plain prefix match on ``backup-app-`` also takes ``backup-app-db-…``, so retention for stack "app" deleted the backups of stack "app-db". """ base = re.escape(backup_basename(stack_id, prefix)) return re.compile(rf"^{base}-(?:full|config)-\d{{8}}-\d{{6}}\.tar\.gz$") # --------------------------------------------------------------------------- # # Locking and stopping # --------------------------------------------------------------------------- # @contextmanager def _locked(stack_id: str, action: str, owner: str = ""): """Hold the stack lock, and register the job so it can be stopped. The lock alone made a stuck backup fatal: nothing could touch the stack until its twelve-hour TTL ran out. The registration is what gives the unlock endpoint something to cancel. """ with Session(engine) as session: try: stack_lock_service.acquire(session, stack_id, action, owner or action, ttl=LOCK_TTL) except stack_lock_service.StackBusy as exc: raise StackBusyError(str(exc)) from exc try: with stack_job_service.track(stack_id, action, owner or action): yield except stack_job_service.JobCancelled as exc: raise BackupCancelled(str(exc)) from exc finally: try: stack_lock_service.release(session, stack_id) except Exception: # noqa: BLE001 - never mask the original error logger.exception("Failed to release the lock on '%s'", stack_id) async def _running(stack_id: str) -> list: try: containers = await asyncio.to_thread(compose_service.containers_for_stack, stack_id) except DockerError as exc: raise BackupError(f"Docker is not reachable: {exc.detail or exc.error}") from exc return [c for c in containers if c.state == "running"] def _tail(result: dict) -> str: text = (result.get("stderr") or result.get("stdout") or "").strip() return text.splitlines()[-1] if text else f"exit {result.get('returncode')}" def _docker_each(ids: list[str], action: str) -> None: client = get_long_client() for container_id in ids: container = safe_call(client.containers.get, container_id) safe_call(getattr(container, action)) async def _compose(stack_id: str, args: list[str]) -> Optional[str]: """Run a compose command; None on success, else what went wrong.""" try: result = await compose_service.run_compose(stack_id, args) except Exception as exc: # noqa: BLE001 - timeouts, missing binary return str(exc) return None if result["returncode"] == 0 else _tail(result) async def _stop(stack_id: str, running: list) -> None: """Stop exactly these containers, or raise and leave them running.""" services = sorted({c.service for c in running}) error = await _compose(stack_id, ["stop", *services]) if error is None: return # Compose fails on a compose file that was edited (or broken) since the # deploy; the containers themselves can still be stopped directly. logger.warning("compose stop failed for %s (%s); stopping containers directly", stack_id, error) try: await asyncio.to_thread(_docker_each, [c.id for c in running], "stop") except Exception as exc: # noqa: BLE001 await _start(stack_id, running) # put back whatever did stop raise BackupError( f"Could not stop '{stack_id}' for a consistent snapshot: {error}" ) from exc async def _start(stack_id: str, running: list) -> Optional[str]: """Start exactly these containers again; None on success.""" if not running: return None services = sorted({c.service for c in running}) error = await _compose(stack_id, ["start", *services]) if error is None: return None try: await asyncio.to_thread(_docker_each, [c.id for c in running], "start") return None except Exception as exc: # noqa: BLE001 logger.warning("Could not restart %s: %s / %s", stack_id, error, exc) return f"{error}; {exc}" # --------------------------------------------------------------------------- # # Selection # --------------------------------------------------------------------------- # def _decide( items: list[dict], key: str, chosen: Optional[list[str]], enabled: bool ) -> list[dict]: """Mark each inventory item ``selected`` (with a reason when it is not). ``chosen`` is an explicit list from the caller; without one the inventory's own defaults apply (everything except system paths, oversized directories and remote-backed storage). """ for item in items: if not enabled: item["selected"], item["reason"] = False, "not requested" elif chosen is not None: selected = item[key] in chosen item["selected"] = selected item["reason"] = None if selected else "not selected" else: item["selected"] = bool(item.get("include_default")) item["reason"] = None if item["selected"] else (item.get("reason") or "not selected") # Never archive plumbing, whatever the caller asked for. if item["selected"] and (item.get("system") or item.get("kind") in ("special", "unknown")): item["selected"] = False item["reason"] = item.get("reason") or "not a regular file or directory" return items def plan( stack_id: str, include_volumes: bool = True, include_binds: bool = True, binds: Optional[list[str]] = None, volumes: Optional[list[str]] = None, ) -> dict: """Decide what a backup captures. Returned as-is by the inventory endpoint.""" inv = assets.inventory(stack_id) _decide(inv["binds"], "source", binds, include_binds) _decide(inv["volumes"], "name", volumes, include_volumes) return inv # --------------------------------------------------------------------------- # # Writing the archive # --------------------------------------------------------------------------- # class _ExactReader: """Hands tarfile exactly ``size`` bytes of a file that may change while it is read. A file that shrinks (a log rotated mid-backup) is padded with zeros instead of aborting inside the member, which would leave the whole archive unreadable; ``short`` records that it happened.""" def __init__(self, fh, size: int): self._fh = fh self._remaining = size self.short = False def read(self, n: int = -1) -> bytes: if n < 0 or n > self._remaining: n = self._remaining data = self._fh.read(n) if len(data) < n: self.short = True data += b"\0" * (n - len(data)) self._remaining -= n return data def _add_tree( tar: tarfile.TarFile, root: str, arcroot: str, skip: set[str], warnings: list[str] ) -> None: """Add the stack directory, tolerating a directory that is in use. ``skip`` holds paths (relative to ``root``) whose *contents* stay out: the directory entry itself is kept so the mount point exists after a restore. Files that vanish mid-walk are left out and unreadable ones reported, rather than one of them failing the whole backup. A remote filesystem mounted somewhere inside is not descended into. """ def add(path: str, rel: str, parent_dev: int) -> None: # A stack directory with a data folder in it can take as long as a # volume, so a cancellation lands here too — between two files, with # the half-written archive thrown away by the caller. stack_job_service.check() arc = f"{arcroot}/{rel}" if rel else arcroot label = rel or "." try: st = os.lstat(path) if stat.S_ISSOCK(st.st_mode): return # a runtime artefact, meaningless in an archive if stat.S_ISREG(st.st_mode): if rel in skip: return with open(path, "rb") as fh: info = tar.gettarinfo(arcname=arc, fileobj=fh) if info.isreg(): reader = _ExactReader(fh, info.size) tar.addfile(info, reader) if reader.short: warnings.append(f"{label}: changed while it was read") else: # a hard link to a file already in the archive tar.addfile(info) return info = tar.gettarinfo(path, arcname=arc) except FileNotFoundError: return except OSError as exc: warnings.append(f"{label}: {exc.strerror or exc}") return if info is None: return tar.addfile(info) if not stat.S_ISDIR(st.st_mode) or rel in skip: return if rel and st.st_dev != parent_dev: remote = assets.remote_mount_type(path) if remote: warnings.append(f"{label}: remote storage ({remote}) mounted here, not included") return try: names = sorted(os.listdir(path)) except OSError as exc: warnings.append(f"{label}: {exc.strerror or exc}") return for name in names: add(os.path.join(path, name), f"{rel}/{name}" if rel else name, st.st_dev) add(root, "", os.lstat(root).st_dev) def _write_archive( dest: str, manifest: dict, directory: str, skip: set[str], parts: list[tuple[str, str]], warnings: list[str], ) -> None: with tarfile.open(dest, "w:gz") as tar: data = json.dumps(manifest, indent=2).encode("utf-8") info = tarfile.TarInfo(MANIFEST_NAME) info.size = len(data) info.mtime = int(compose_service.now().timestamp()) tar.addfile(info, io.BytesIO(data)) _add_tree(tar, directory, "compose", skip, warnings) for part, arcname in parts: tar.add(part, arcname=arcname) os.unlink(part) # keep the peak disk use to one copy of the data # --------------------------------------------------------------------------- # # Backup # --------------------------------------------------------------------------- # def _rel_inside(path: str, directory: str) -> Optional[str]: rel = os.path.relpath(path, directory) if rel == "." or rel.startswith(".." + os.sep) or rel == "..": return None return rel async def create_backup_ex( stack_id: str, name: str, include_volumes: bool = True, stop_first: bool = True, include_binds: bool = True, binds: Optional[list[str]] = None, volumes: Optional[list[str]] = None, ) -> tuple[str, dict]: """Create a backup tar.gz. Returns (path, report). The report's ``errors`` lists data that should have been captured and was not, and ``restart_error`` a stack that could not be started again — both mean the backup must not be reported as a plain success. """ directory = compose_service.stack_dir(stack_id) if not os.path.isdir(directory): raise BackupError("Stack directory missing") with _locked(stack_id, "backup"): return await _create( stack_id, name, directory, include_volumes, stop_first, include_binds, binds, volumes ) async def _create( stack_id: str, name: str, directory: str, include_volumes: bool, stop_first: bool, include_binds: bool, binds: Optional[list[str]], volumes: Optional[list[str]], ) -> tuple[str, dict]: stack_job_service.phase("looking at what to capture") selection = await asyncio.to_thread( plan, stack_id, include_volumes, include_binds, binds, volumes ) selected_binds = [b for b in selection["binds"] if b["selected"]] # Selected bind sources this process cannot reach through the filesystem # need their own archive; the rest already ride along in compose/. cap_binds = [b for b in selected_binds if b["via"] == "archive"] tree_binds = [b for b in selected_binds if b["via"] != "archive"] cap_volumes = [v for v in selection["volumes"] if v["selected"]] skipped_binds = [b for b in selection["binds"] if not b["selected"]] skipped_volumes = [v for v in selection["volumes"] if not v["selected"]] # Deselected data that sits inside the stack folder must not sneak into # the archive through compose/ (that is how a 200 GB downloads folder # ends up in a "config only" backup). A restore leaves these alone. excluded = sorted( { rel for b in skipped_binds if b.get("inside_stack_dir") and (rel := _rel_inside(b["source"], directory)) } ) compose_binds = sorted( {rel for b in tree_binds if (rel := _rel_inside(b["source"], directory))} ) # Consistent snapshot: stop what runs — data folders inside the stack # directory count as data too — and start exactly that again afterwards. stopped: list = [] if stop_first and (cap_volumes or selected_binds): running = await _running(stack_id) if running: await _stop(stack_id, running) stopped = running workdir = tempfile.mkdtemp(prefix="sp-backup-") archive_path: Optional[str] = None warnings: list[str] = [] restart_error: Optional[str] = None try: parts: list[tuple[str, str]] = [] for index, bind in enumerate(cap_binds): # Between two items is where a cancelled backup gives up: never in # the middle of one, and never after the stack has been stopped # without the finally below starting it again. stack_job_service.check() stack_job_service.phase(f"bind {bind['source']}") part = os.path.join(workdir, f"bind-{index:03d}.tar") try: bind["bytes"] = await asyncio.to_thread( assets.export_path, bind["source"], bind["kind"], part ) bind["archive"] = f"binds/{index:03d}.tar" parts.append((part, bind["archive"])) except Exception as exc: # noqa: BLE001 # Cancelling pulls the helper container out from under the # read, so the failure here *is* the cancellation. stack_job_service.check() logger.warning("Could not archive bind %s: %s", bind["source"], exc) bind["archive"], bind["error"] = None, str(exc) for index, vol in enumerate(cap_volumes): stack_job_service.check() stack_job_service.phase(f"volume {vol['name']}") part = os.path.join(workdir, f"vol-{index:03d}.tar") try: vol["bytes"] = await asyncio.to_thread(assets.export_volume, vol["name"], part) vol["archive"] = f"volumes/{vol['name']}.tar" parts.append((part, vol["archive"])) except Exception as exc: # noqa: BLE001 stack_job_service.check() logger.warning("Could not archive volume %s: %s", vol["name"], exc) vol["archive"], vol["error"] = None, str(exc) failed = [b for b in cap_binds if b.get("error")] + [ v for v in cap_volumes if v.get("error") ] manifest = { "format_version": BACKUP_FORMAT_VERSION, "stack_id": stack_id, "name": name, "created_at": compose_service.now().isoformat(), "include_volumes": include_volumes, "include_binds": include_binds, "stack_dir": directory, "path_mismatch": selection.get("path_mismatch"), "stopped": sorted({c.service for c in stopped}), # Data folders carried inside compose/, and folders whose contents # were left out of it (kept as they are by a restore). "compose_binds": compose_binds, "excluded": excluded, # Volumes keep the v1 shape (full/short/labels) so older StackPilots # can still read the manifest they care about. "volumes": [ { "full": v["name"], "short": v["short"], "labels": v["labels"], "driver": v.get("driver"), "options": v.get("options") or {}, "external": v.get("external", False), "archive": v["archive"], "remote": v.get("remote", False), "bytes": v.get("bytes"), } for v in cap_volumes if v.get("archive") ], "binds": [ { "source": b["source"], "kind": b["kind"], "mounts": b["mounts"], "inside_stack_dir": b["inside_stack_dir"], "archive": b["archive"], "bytes": b.get("bytes"), } for b in cap_binds if b.get("archive") ], "skipped": [ {"kind": "bind", "source": b["source"], "reason": b.get("reason")} for b in skipped_binds ] + [ {"kind": "volume", "name": v["name"], "reason": v.get("reason")} for v in skipped_volumes ] + [ { "kind": "volume" if "name" in item else "bind", **({"name": item["name"]} if "name" in item else {"source": item["source"]}), "reason": f"backup failed: {item['error']}", } for item in failed ], } stack_job_service.check() stack_job_service.phase("writing the archive") fd, archive_path = tempfile.mkstemp(prefix=f"sp-{stack_id}-", suffix=".tar.gz") os.close(fd) await asyncio.to_thread( _write_archive, archive_path, manifest, directory, set(excluded), parts, warnings ) except BaseException: if archive_path and os.path.exists(archive_path): os.unlink(archive_path) raise finally: shutil.rmtree(workdir, ignore_errors=True) if stopped: restart_error = await _start(stack_id, stopped) errors = [f"{item.get('source') or item.get('name')}: {item['error']}" for item in failed] report = { "file": archive_path, "binds": [ {"source": b["source"], "bytes": b.get("bytes") or b.get("size"), "error": b.get("error")} for b in tree_binds + cap_binds ], "volumes": [ {"name": v["name"], "bytes": v.get("bytes"), "error": v.get("error")} for v in cap_volumes ], "skipped": manifest["skipped"], "path_mismatch": selection.get("path_mismatch"), "stopped": manifest["stopped"], "errors": errors, "warnings": warnings, "restart_error": restart_error, "size": os.path.getsize(archive_path), } return archive_path, report async def create_backup( stack_id: str, name: str, include_volumes: bool = True, stop_first: bool = True, include_binds: bool = True, binds: Optional[list[str]] = None, volumes: Optional[list[str]] = None, ) -> str: path, _report = await create_backup_ex( stack_id, name, include_volumes, stop_first, include_binds, binds, volumes ) return path # --------------------------------------------------------------------------- # # Reading and verifying # --------------------------------------------------------------------------- # def read_manifest(tar_path: str) -> dict: """The manifest, read without decompressing the rest (it comes first).""" try: with tarfile.open(tar_path, "r:gz") as tar: for member in tar: if member.name == MANIFEST_NAME: fh = tar.extractfile(member) if fh is None: break return json.loads(fh.read().decode("utf-8")) except (tarfile.TarError, OSError, EOFError, zlib.error, ValueError) as exc: raise BackupError(f"Backup archive is damaged or incomplete: {exc}") from exc raise BackupError("Backup is missing its manifest") def verify_archive(tar_path: str) -> None: """Read the whole archive once, so a truncated or corrupt file is refused before a restore deletes anything. Draining the gzip stream to its end is what checks its CRC.""" try: with tarfile.open(tar_path, "r:gz") as tar: for member in tar: if member.isreg(): fh = tar.extractfile(member) while fh is not None and fh.read(1024 * 1024): pass while tar.fileobj.read(1024 * 1024): pass except (tarfile.TarError, OSError, EOFError, zlib.error) as exc: raise BackupError(f"Backup archive is damaged or incomplete: {exc}") from exc # --------------------------------------------------------------------------- # # Restore — stack directory # --------------------------------------------------------------------------- # def _safe_target(dest_dir: str, rel: str) -> str: """Resolve a member path inside dest_dir, refusing traversal *and* writes through a symlink planted earlier in the same archive.""" root = os.path.abspath(dest_dir) target = os.path.normpath(os.path.join(root, rel)) if target != root and not target.startswith(root + os.sep): raise BackupError(f"Refusing unsafe path in backup: {rel}") parent = os.path.dirname(target) if os.path.exists(parent): real_parent = os.path.realpath(parent) if real_parent != root and not real_parent.startswith(root + os.sep): raise BackupError(f"Refusing unsafe path in backup: {rel}") return target def _apply_meta(path: str, member: tarfile.TarInfo) -> None: """Restore mode/ownership/mtime — *arr-style images run as PUID/PGID and break when their config comes back root-owned with default permissions.""" try: os.chown(path, member.uid, member.gid) except (OSError, AttributeError): pass try: # After chown, which clears setuid/setgid bits. os.chmod(path, member.mode) except OSError: pass try: os.utime(path, (member.mtime, member.mtime)) except OSError: pass def _under(rel: str, prefixes: set[str]) -> bool: return any(rel.startswith(p + "/") for p in prefixes) def _extract_tree( tar: tarfile.TarFile, prefix: str, dest_dir: str, skip: frozenset | set = frozenset() ) -> None: """Extract one subtree of the archive, preserving metadata and symlinks. Contents under a ``skip`` path (relative) are not extracted; the path's own directory entry still is. """ os.makedirs(dest_dir, exist_ok=True) root_name = prefix.rstrip("/") dirs: list[tuple[str, tarfile.TarInfo]] = [] for member in tar.getmembers(): if member.name == root_name: if member.isdir(): dirs.append((dest_dir, member)) continue if not member.name.startswith(prefix): continue rel = member.name[len(prefix) :].lstrip("/") if not rel or _under(rel, skip): continue target = _safe_target(dest_dir, rel) existing_dir = os.path.isdir(target) and not os.path.islink(target) if member.isdir(): if os.path.lexists(target) and not existing_dir: os.unlink(target) os.makedirs(target, exist_ok=True) dirs.append((target, member)) continue os.makedirs(os.path.dirname(target), exist_ok=True) # Never write through (or over) something an earlier member put here: # open() would follow a symlink to wherever it points. if existing_dir: shutil.rmtree(target) elif os.path.lexists(target): os.unlink(target) if member.issym(): os.symlink(member.linkname, target) continue # chmod/utime would follow the link if member.islnk(): source = _safe_target(dest_dir, member.linkname[len(prefix) :].lstrip("/")) if os.path.exists(source): os.link(source, target) continue if not member.isreg(): continue # devices/fifos/sockets are runtime artefacts src = tar.extractfile(member) if src is None: continue with open(target, "wb") as out: shutil.copyfileobj(src, out) _apply_meta(target, member) # Directory metadata last: a 0500 directory would block writing its files. for target, member in sorted(dirs, key=lambda d: len(d[0]), reverse=True): _apply_meta(target, member) def _remove_tree(path: str, dev: int, rel: str, warnings: list[str]) -> None: """rmtree that never crosses into another filesystem (a mounted disk or share inside the stack folder is left as it is).""" with os.scandir(path) as it: entries = list(it) for entry in entries: entry_rel = f"{rel}/{entry.name}" if entry.is_dir(follow_symlinks=False): if entry.stat(follow_symlinks=False).st_dev != dev: warnings.append(f"{entry_rel}: another filesystem is mounted here, left untouched") continue _remove_tree(entry.path, dev, entry_rel, warnings) else: os.unlink(entry.path) try: os.rmdir(path) except OSError: pass # still holds a mount point def _clear(directory: str, preserve: set[str], warnings: list[str]) -> None: """Empty the stack directory for the restored tree, except what the backup does not contain: ``preserve`` paths and other filesystems mounted inside.""" root_dev = os.lstat(directory).st_dev def walk(path: str, rel: str) -> None: with os.scandir(path) as it: entries = list(it) for entry in entries: entry_rel = f"{rel}/{entry.name}" if rel else entry.name if entry_rel in preserve: continue if entry.is_dir(follow_symlinks=False): if entry.stat(follow_symlinks=False).st_dev != root_dev: warnings.append( f"{entry_rel}: another filesystem is mounted here, left untouched" ) continue if any(p.startswith(entry_rel + "/") for p in preserve): walk(entry.path, entry_rel) else: _remove_tree(entry.path, root_dev, entry_rel, warnings) else: os.unlink(entry.path) walk(directory, "") def _copy_dir_meta(src: str, dst: str) -> None: st = os.lstat(src) try: os.chown(dst, st.st_uid, st.st_gid) os.chmod(dst, stat.S_IMODE(st.st_mode)) os.utime(dst, (st.st_atime, st.st_mtime)) except OSError: pass def _merge(src: str, dst: str, rel: str, warnings: list[str]) -> None: """Move the staged tree into the (cleared) stack directory.""" for name in sorted(os.listdir(src)): s, d = os.path.join(src, name), os.path.join(dst, name) entry_rel = f"{rel}/{name}" if rel else name s_dir = os.path.isdir(s) and not os.path.islink(s) if os.path.lexists(d): d_dir = os.path.isdir(d) and not os.path.islink(d) if s_dir and d_dir: _merge(s, d, entry_rel, warnings) _copy_dir_meta(s, d) continue if d_dir: # Only kept (preserved or mounted) directories survive _clear. warnings.append(f"{entry_rel}: kept the existing folder, the backup has a file here") continue os.unlink(d) shutil.move(s, d) def _restore_tree( tar: tarfile.TarFile, directory: str, preserve: set[str], skip_extract: set[str], warnings: list[str], ) -> None: """Replace the stack directory with the backup's, staged next to it first so a failing extraction leaves the old one untouched.""" root = os.path.dirname(directory) os.makedirs(root, exist_ok=True) staging = tempfile.mkdtemp(prefix=f".restore-{os.path.basename(directory)}-", dir=root) try: _extract_tree(tar, "compose/", staging, skip=skip_extract) if not os.path.isdir(directory): shutil.move(staging, directory) return _clear(directory, preserve, warnings) _merge(staging, directory, "", warnings) _copy_dir_meta(staging, directory) finally: shutil.rmtree(staging, ignore_errors=True) def _tree_paths(manifest: dict) -> tuple[set[str], set[str]]: """(excluded, compose_binds) relative to the stack directory. Format 3 records them. For older backups the excluded folders are worked out from the skipped binds; which data folders compose/ carries is unknown. """ if "excluded" in manifest: return set(manifest.get("excluded") or []), set(manifest.get("compose_binds") or []) old_dir = manifest.get("stack_dir") or "" excluded = set() for item in manifest.get("skipped", []): if item.get("kind") == "bind" and old_dir and item.get("source"): rel = _rel_inside(item["source"], old_dir) if rel: excluded.add(rel) return excluded, set() # --------------------------------------------------------------------------- # # Restore # --------------------------------------------------------------------------- # def _target_id(manifest: dict, target_id: Optional[str]) -> str: raw = target_id or manifest.get("stack_id") or "" if not raw.strip(): raise BackupError("Backup manifest has no stack id") # Slugify whichever id we end up using — the manifest comes from an # uploaded file, so its stack_id must never be able to escape STACKS_DIR. return compose_service.slugify(raw) def _extract_member(tar: tarfile.TarFile, name: str) -> Optional[str]: """Copy one archive member to a temp file; None if it is missing.""" try: member = tar.getmember(name) except KeyError: return None fh = tar.extractfile(member) if fh is None: return None with tempfile.NamedTemporaryFile(delete=False, suffix=".tar") as tmp: shutil.copyfileobj(fh, tmp) return tmp.name def restore_backup( tar_path: str, target_id: Optional[str] = None, overwrite: bool = False, restore_volumes: bool = True, restore_binds: bool = True, verified: bool = False, ) -> dict: """Restore a backup's files, folders and volumes. Returns a report. This is the part that writes; :func:`restore` wraps it with the lock and with stopping and starting the stack. """ manifest = read_manifest(tar_path) stack_id = _target_id(manifest, target_id) old_id = compose_service.slugify(manifest.get("stack_id") or stack_id) renamed = stack_id != old_id # Volumes are named after the compose *project*, which differs from the id # for a folder compose had to normalise ("my.app" -> "myapp_data"). old_project = compose_service.project_name(manifest.get("stack_id") or stack_id) new_project = compose_service.project_name(stack_id) old_dir = manifest.get("stack_dir") or "" directory = compose_service.stack_dir(stack_id) if os.path.isdir(directory) and not overwrite: raise BackupError(f"Stack '{stack_id}' already exists") if not verified: verify_archive(tar_path) excluded, compose_binds = _tree_paths(manifest) # Not restoring data folders means keeping the ones there are, not # emptying them: compose/ carries those inside the stack directory. held_back = compose_binds if not restore_binds else set() volumes_restored = 0 binds_restored = 0 skipped: list[dict] = [] warnings: list[str] = [] with tarfile.open(tar_path, "r:gz") as tar: _restore_tree(tar, directory, excluded | held_back, held_back, warnings) skipped += [{"kind": "bind", "source": rel, "reason": "not requested"} for rel in held_back] for bind in manifest.get("binds", []): archive = bind.get("archive") if not archive: continue source = bind["source"] if not restore_binds: skipped.append({"kind": "bind", "source": source, "reason": "not requested"}) continue if bind.get("inside_stack_dir") and old_dir: # A renamed stack must not write into the old stack's folder. source = os.path.normpath(os.path.join(directory, os.path.relpath(source, old_dir))) elif renamed: skipped.append({ "kind": "bind", "source": source, "reason": f"belongs to the original stack '{old_id}'; " "restore under that name to write it back", }) continue if assets.is_system_path(source): skipped.append({"kind": "bind", "source": source, "reason": "system path"}) continue part = _extract_member(tar, archive) if part is None: skipped.append({"kind": "bind", "source": source, "reason": "missing from archive"}) continue try: assets.import_path(source, bind.get("kind", "dir"), part) binds_restored += 1 except Exception as exc: # noqa: BLE001 logger.warning("Could not restore bind %s: %s", source, exc) skipped.append({"kind": "bind", "source": source, "reason": str(exc)}) finally: os.unlink(part) for v in manifest.get("volumes", []): full = v["full"] if not restore_volumes: skipped.append({"kind": "volume", "name": full, "reason": "not requested"}) continue retargeted = False if old_project != new_project and full.startswith(old_project + "_"): full = new_project + full[len(old_project) :] retargeted = True labels = dict(v.get("labels") or {}) if not v.get("external"): # Re-target compose's labels to the (possibly new) project. labels[COMPOSE_PROJECT_LABEL] = new_project reason = _volume_conflict(full, new_project, old_id, renamed and not retargeted) if reason: skipped.append({"kind": "volume", "name": full, "reason": reason}) continue part = _extract_member(tar, v.get("archive") or f"volumes/{v['full']}.tar") if part is None: skipped.append({"kind": "volume", "name": full, "reason": "missing from archive"}) continue try: # Remote-backed volumes (NFS/CIFS) are never wiped: that # would delete the share the volume points at. assets.import_volume( full, labels, part, wipe=not v.get("remote", False), driver=v.get("driver"), driver_opts=v.get("options") or None, ) volumes_restored += 1 except Exception as exc: # noqa: BLE001 logger.warning("Could not restore volume %s: %s", full, exc) skipped.append({"kind": "volume", "name": full, "reason": str(exc)}) finally: os.unlink(part) # What went wrong now, as opposed to what the backup itself left out # (listed in skipped as well, for the full picture). problems = [ f"{item.get('name') or item.get('source')}: {item['reason']}" for item in skipped if item["reason"] != "not requested" ] + warnings skipped += manifest.get("skipped", []) return { "stack_id": stack_id, # Restored under a new id, the copy must not carry the original's # display name — two stacks called the same in the list is how the # wrong one gets stopped. "name": stack_id if renamed else manifest.get("name", stack_id), "volumes_restored": volumes_restored, "binds_restored": binds_restored, "skipped": skipped, "warnings": warnings, "problems": problems, } def _volume_conflict(full: str, project: str, old_id: str, shared_with_original: bool) -> Optional[str]: """Why a volume must not be overwritten, or None if it may be.""" attrs = assets.volume_attrs(full) if attrs is None: return None # created fresh owner = (attrs.get("Labels") or {}).get(COMPOSE_PROJECT_LABEL) if owner and owner != project: return f"belongs to stack '{owner}'; not overwritten" if shared_with_original: return ( f"is not named after the stack, so it is still the original " f"'{old_id}' stack's volume; not overwritten" ) users = assets.running_users(full) if users: return f"in use by running container(s) {', '.join(users)}; not overwritten" return None async def restore( tar_path: str, target_id: Optional[str] = None, overwrite: bool = False, restore_volumes: bool = True, restore_binds: bool = True, ) -> dict: """Restore with the stack locked, stopped while its data is replaced, and brought back up afterwards if it was running.""" manifest = await asyncio.to_thread(read_manifest, tar_path) stack_id = _target_id(manifest, target_id) directory = compose_service.stack_dir(stack_id) if os.path.isdir(directory) and not overwrite: raise BackupError(f"Stack '{stack_id}' already exists") with _locked(stack_id, "restore"): await asyncio.to_thread(verify_archive, tar_path) try: running = await _running(stack_id) except BackupError: running = [] # no Docker: the volume part will say so if running: # Replacing a database's files under it corrupts it. await _stop(stack_id, running) try: result = await asyncio.to_thread( restore_backup, tar_path, target_id, overwrite, restore_volumes, restore_binds, True, ) except BaseException: if running: await _start(stack_id, running) raise result["restarted"] = False if running: # up, not start: the restored compose file may differ from what ran. error = await _compose(stack_id, ["up", "-d", "--remove-orphans"]) result["restarted"] = error is None if error: result["restart_error"] = error result["problems"].append(f"stack did not start again: {error}") return result