Backup Control Scripting

The script dupltool is a wrapper for duplicity that usually just invokes duplicity with all arguments passed on, but every month it first makes a stash of the most recent succession of daily snapshots, so that the duplicity run at this time is a monthly snapshot.

The script duplicity-daily is a simple control script for daily backup that uses configuration from /etc/duplicity-daily.conf that defines which backups to make, and from ~/.ssh/config as to how to connect to the target host (or hosts).

Administration Example

This is a /etc/duplicity-daily sample

ENABLED=yes
OPTIONS=--no-encryption
TARGET=backup/backup
/root
/etc
/home

The above sample declares backup (without encryption) of directory trees /root, /etc, /home to host backup (as declared in ~/.ssh/config) into directories under the user’s directory backup.

This is a ~/.ssh/config sample

host backup
    hostname backup.lan
    user thishost
    identityfile ~/.ssh/thishost-backup
    ServerAliveInterval 15
    ServerAliveCountMax 4
    TCPKeepAlive yes
    RekeyLimit 100M
    IPQoS reliability

Note that for the above sample, the backup client root@thishost has prepared a password-less ssh key to thishost@backup.lan so that daily backup can happen without operator intervention.

Debian Package

A debian package is built with

$ make deb

provided that the build environment is set up, i.e. an ordinary debian package building environment.

The package is then installed with

# dpkg -i ../buckap_<TAB>

Doing so will install /usr/bin/dupltool and /etc/cron.daily/duplicity-daily, as well as providing an example /etc/duplicity-daily.conf (incuding rudimentary instructions).