borg-backup-sshfs-scriptware

Scripting around borg backup and sshfs

I. About this scriptware (general info)

This backup script was developed with the idea being executed by external scheduler, eg. cron. As more modern approaches are available today, this script is not actively used nor developed.

Main compoments:

• libs/*.sh - common functions used by main script
• backup.conf - customization of backup policies
• do_backup.sh - main script
• secrets - plaintext file containing borg password - eg.: export BORG_PASSPHRASE='*redactedPassword*'

high-level backup workflow description

1. Script checks if sshfs is already mounted. If yes, we end here, as it usually means already running backup, or something weird.
2. Remote backup repo is mounted using sshfs, mount is checked if borg repo directory is present there.
3. Borg backup of home directories is performed into backup_repo_path
4. Borg backup of /etc dir is done into sys_repo_path
5. Local postgres is dumped with pg_dumpall, this dump is backed up into sys_repo_path and finally removed
6. Borg backup of /root dir is done into sys_repo_path
7. Borg prune is executed on both repositories
8. Borg compact is executed on both repositories
9. sshfs mount is unmounted

CLI switches:

• -o,--osonly - backup only system part
• -d,--debug - show more info
• -u,--umount - umounts (if mounted) ssfs mount (possibly previously mounted with -m. No backup is performed.
• -m,--mountonly - mounts sshfs mount only. No backup is performed.
• -i,--ignoremount - proceeds with backup in case the mount is already mounted, eg. in case of script development
• -v,--verbose - show more info
• -s,--skipcheck - skip repository check at the end of procedure
• -p,--pruneonly - only perform repository prune. No backup is performed.

dependencies

• borgbackup, sshfs - at recent debian avaiable from standard repositories..

II. usage tips

Before any borg action, source secrets: source secrets to have BORG_PASSWORD in environment.

Usually ./do_backup.sh -m is needed before any borg-related action to ensure the repository is available (= mounted via sshfs).

At the end of session, do ./do_backup.sh -u to ensure mountpoint is cleanly unmounted and is not possibly blocking regular backups.

RESTORE howto

Most useful usecase I.M.O :).

Task definition: we want to restore authorized_keys file of user 'eve'.

1. ./do_backup.sh -m to mount remote sshfs
2. source secrets - to have BORG_PASSWORD in environment
3. borg list /mnt/mp/repopath | grep eve - to see archives containing username eve - gives us:

root@host:~/backup# borg list /mnt/mp/repopath | grep eve
home_users_eve-2022-06-14T18:47:37  Tue, 2022-06-14 18:47:39 [426a9423b744a8c09169d07ba0e833f3fdb1d6729c99a33ecca0ee042bff1cb1]
home_users_eve-2022-06-14T21:05:03  Tue, 2022-06-14 21:05:05 [cb9cb7ed46665666f3594466910fc26aacfd064546f63225c42cb03f7aab7e1c]
home_users_eve-2022-06-15T00:01:40  Wed, 2022-06-15 00:01:42 [c05dc47235cc8e183109f4e3104fa9dab4e2f086797aa6f54dbb20e5ac3e4510]
root@host:~/backup#

4. oki, we want version from 14.6. 21:05:03. - we can mount the archive as fuse filesystem: borg mount /mnt/mp/repopath::home_users_eve-2022-06-14T21:05:03 /mnt/borgrestore - please note the repository string containing the repository path and archive name separated by two colons (::).
5. at the mountpoint we can access the content of backup archive, so we can recover the file we need