mirror of
https://github.com/kevinveenbirkenbach/docker-volume-backup.git
synced 2026-08-24 23:04:34 +00:00
Kevin Veen-Birkenbach
da9c3a1e6f
A volume with a backing store of its own is not in a snapshot of the docker data root: it appears there as an existing empty directory, so the copy succeeds, the generation is stamped complete, and the volume is empty in it. The existing check only asked whether the path was inside the snapshot, which that empty directory answers with yes. The driver, its options and the filesystem the mountpoint sits on now decide, per volume. An uncaptured volume is copied live - correct data without the point in time - while every other volume of the same run keeps its snapshot. One NFS volume no longer costs the whole host its consistent backup. A volume resolving outside the subject degrades the same way instead of aborting the run. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
146 lines
5.0 KiB
Python
146 lines
5.0 KiB
Python
"""Back up every Docker volume of a host into a timestamped generation."""
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from __future__ import annotations
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import os
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from contextlib import ExitStack
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from datetime import datetime
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from .cli import parse_args
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from .compose import handle_docker_compose_services
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from .docker import (
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change_containers_status,
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containers_using_volume,
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docker_volume_names,
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filter_stoppable,
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)
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from .dumps import backup_dumps_for_volume, load_databases_df
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from .layout import (
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create_version_directory,
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create_volume_directory,
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get_machine_id,
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stamp_directory,
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)
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from .policy import requires_stop, volume_is_fully_ignored
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from .snapshot import snapshot_source, volume_snapshot
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from .volume import backup_volume, inspect_backing
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def main() -> int:
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args = parse_args()
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machine_id = get_machine_id()
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# Local wall clock on purpose: generations sort by this name, and UTC would
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# order new ones before the existing ones wherever the offset is positive.
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backup_time = datetime.now().strftime("%Y%m%d%H%M%S") # noqa: DTZ005
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versions_dir = os.path.join(args.backups_dir, machine_id, args.repo_name)
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version_dir = create_version_directory(versions_dir, backup_time)
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databases_df = load_databases_df(args.databases_csv)
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print("💾 Start volume backups...", flush=True)
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with ExitStack() as stack:
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resolve_source = None
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if args.snapshot:
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resolve_source = stack.enter_context(
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volume_snapshot(args.snapshot, args.snapshot_subject, backup_time)
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)
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for volume_name in docker_volume_names():
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print(f"Start backup routine for volume: {volume_name}", flush=True)
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if volume_name in args.volumes_no_backup_required:
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print(
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f"Skipping volume '{volume_name}' entirely (declared no-backup).",
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flush=True,
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)
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continue
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containers = containers_using_volume(volume_name)
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if volume_is_fully_ignored(containers, args.images_no_backup_required):
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print(
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f"Skipping volume '{volume_name}' entirely (all linked containers are ignored).",
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flush=True,
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)
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continue
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vol_dir = create_volume_directory(version_dir, volume_name)
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found_db, dumped_any = backup_dumps_for_volume(
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containers=containers,
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vol_dir=vol_dir,
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databases_df=databases_df,
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database_containers=args.database_containers,
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)
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if args.dump_only_sql and found_db:
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if not dumped_any:
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print(
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f"WARNING: dump-only-sql requested but no DB dump was produced for DB volume '{volume_name}'. "
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"Falling back to file backup.",
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flush=True,
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)
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else:
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continue
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backing = inspect_backing(volume_name)
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live_source = backing.source
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def copy(
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*,
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authoritative: bool,
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source: str = live_source,
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volume: str = volume_name,
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target: str = vol_dir,
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) -> None:
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backup_volume(
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versions_dir,
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volume,
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target,
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authoritative=authoritative,
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source=source,
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)
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if resolve_source is not None:
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source, reason = snapshot_source(
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resolve_source, backing, args.snapshot_subject
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)
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if source is not None:
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copy(authoritative=True, source=source)
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else:
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print(
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f"WARNING: volume '{volume_name}' is not in the snapshot "
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f"({reason}); copying it live instead.",
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flush=True,
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)
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copy(authoritative=False)
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continue
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if args.everything:
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stoppable = filter_stoppable(containers)
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copy(authoritative=False)
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change_containers_status(stoppable, "stop")
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copy(authoritative=True)
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if not args.shutdown:
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change_containers_status(stoppable, "start")
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continue
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copy(authoritative=False)
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if requires_stop(containers, args.images_no_stop_required):
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stoppable = filter_stoppable(containers)
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change_containers_status(stoppable, "stop")
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copy(authoritative=True)
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if not args.shutdown:
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change_containers_status(stoppable, "start")
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stamp_directory(version_dir)
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print("Finished volume backups.", flush=True)
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print("Handling Docker Compose services...", flush=True)
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handle_docker_compose_services(args.compose_dir, args.hard_restart_projects)
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return 0
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