Configuration

B4 Backup got a configuration YAML file, where you can override specific parameters as you like. The default configuration path is ~/.config/b4_backup.yml.

A full reference of all possible settings and their default values can be found in the code reference.

Example configuration based on default values

backup_targets:
  _default:
    destination: null
    dst_retention:
      _default:
        all: forever
      auto:
        1day: 1month
        1month: infinity
        1week: 1year
    if_dst_dir_not_found: CREATE
    replaced_target_ttl: 24hours
    restore_strategy: SAFE
    source: null
    src_retention:
      _default:
        all: '1'
      auto:
        all: 7days
    src_snapshot_dir: &id001 .b4_backup
    subvolume_rules:
      /:
        backup_strategy: FULL
        fallback_strategy: DROP
      _default:
        backup_strategy: FULL
        fallback_strategy: DROP
      rootfs/var/lib/docker/btrfs/subvolumes:
        backup_strategy: IGNORE
        fallback_strategy: DROP
  local/data:
    destination: null
    dst_retention: {}
    if_dst_dir_not_found: CREATE
    replaced_target_ttl: 24hours
    restore_strategy: SAFE
    source: /opt/data
    src_retention: {}
    src_snapshot_dir: *id001
    subvolume_rules:
      /:
        backup_strategy: FULL
        fallback_strategy: DROP
      _default:
        backup_strategy: FULL
        fallback_strategy: DROP
      rootfs/var/lib/docker/btrfs/subvolumes:
        backup_strategy: IGNORE
        fallback_strategy: DROP
  localhost/test:
    destination: null
    dst_retention: {}
    if_dst_dir_not_found: CREATE
    replaced_target_ttl: 24hours
    restore_strategy: SAFE
    source: ssh://root@localhost/opt/test
    src_retention: {}
    src_snapshot_dir: *id001
    subvolume_rules:
      /:
        backup_strategy: FULL
        fallback_strategy: DROP
      _default:
        backup_strategy: FULL
        fallback_strategy: DROP
      rootfs/var/lib/docker/btrfs/subvolumes:
        backup_strategy: IGNORE
        fallback_strategy: DROP
  main.example.com/b:
    destination: null
    dst_retention: {}
    if_dst_dir_not_found: CREATE
    replaced_target_ttl: 24hours
    restore_strategy: SAFE
    source: ssh://root@main.example.com:990/b
    src_retention: {}
    src_snapshot_dir: *id001
    subvolume_rules:
      /:
        backup_strategy: FULL
        fallback_strategy: DROP
      _default:
        backup_strategy: FULL
        fallback_strategy: DROP
      rootfs/var/lib/docker/btrfs/subvolumes:
        backup_strategy: IGNORE
        fallback_strategy: DROP
  main.example.com/home:
    destination: null
    dst_retention:
      auto:
        all: 3days
    if_dst_dir_not_found: CREATE
    replaced_target_ttl: 24hours
    restore_strategy: SAFE
    source: ssh://root@main.example.com/home
    src_retention: {}
    src_snapshot_dir: *id001
    subvolume_rules:
      /:
        backup_strategy: FULL
        fallback_strategy: DROP
      _default:
        backup_strategy: FULL
        fallback_strategy: DROP
      rootfs/var/lib/docker/btrfs/subvolumes:
        backup_strategy: IGNORE
        fallback_strategy: DROP
config_path: ~/.config/b4_backup.yml
default_targets: []
logging:
  loggers:
    root:
      level: INFO
timezone: utc

Tip

B4 Backup is using OmegaConf to parse config files. OmegaConf also supports variables and resolvers. With resolvers it is possible to insert for example environment variables.
A list of all built-in resolvers can be found here. B4 Backup implements some resolvers too. You can find them here.