services:
  backup:
    container_name: backup
    init: true
    tty: true
    build:
      context: .
    environment:
      - TZ=Europe/London
      - SLEEP_TIME=1h # we will wait an hour between backups

      # first backup goes to rsync.net
      - BORG_PASSPHRASE_0=$PASSWORD
      - BORG_REMOTE_PATH_0=borg1 # we must use this executable in the rsync.net host
      - BORG_REPO_0=my-username@my-username.rsync.net:~/backup

      # second backup goes to a local path
      - BORG_PASSPHRASE_1=$PASSWORD
      - BORG_REPO_1=/local-backup

      # the following are passed to `borg prune`
      - KEEP_DAILY=6 # default: 6
      - KEEP_WEEKLY=3 # default: 3
      - KEEP_MONTHLY=48 # default: 48
      - KEEP_YEARLY=10 # default: 0
    volumes:
      - /volumes:/source:ro # we will backup this folder, we mustn't change it, so it's readonly
      - /volumes/backup:/snapshot # we must mount a btrfs path for the snapshot to be put at, this is just a temporary path
      - /volumes/backup/logs:/backup-logs # we will store the output of the backup commands in this folder
      - borg-cache:/root/.cache/borg # speed up subsequent backups

      - /bulk/backup:/local-backup # this is an example target backup path for BORG_REPO_1 from above
      - /volumes/backup/config/id_rsa:/root/.ssh/id_rsa # this is an example for mounting an ssh key for a remote repo (BORG_REPO_0 above)

    cap_add:
      - SYS_ADMIN # we need this capability to snapshot a btrfs volume
    restart: unless-stopped

volumes:
  borg-cache: