#!/bin/sh

# ssh://git.mdcc.cx/git/ad1810-stuff.git
# ( view recent version online at http://mdcc.cx/git/wd/ad1810-stuff/scripts/a1-s3dup )
#
# This file is in the public domain.
# Author: Joost van Baal-Ilić, march 2014
# Inspired upon an idea by Thomas Sileo
# ( see https://gist.github.com/tsileo/3147209 and
# http://thomassileo.com/blog/2012/07/19/ubuntu-slash-debian-encrypted-incremental-backups-with-duplicity-on-amazon-s3/ )
#

#
# needed software
#  apt -V install duplicity
#
# example configuration file
# 
# cat <<EOT >/usr/local/etc/a1-s3dup.conf
# AWS_ACCESS_KEY_ID=ABCDEFGHIJKLMNOPQRST
# AWS_SECRET_ACCESS_KEY=A1b2C3d4EfGhIjKlMnOPq5r6s7t8u9v0WxYz1a2B
# BUCKET=s3+http://foo.systems.bar.s3.amazonaws.com
# PASSPHRASE=s3kr3+Pa5s
# EOT
#
# enable to be run from cron:
#
# cat <<EOT >/etc/cron.d/a1-s3dup
# PATH=/usr/local/bin:/usr/bin:/bin
# MAILTO=root
# @daily a1-s3dup a1-s3dup
# EOT
#
# in order to restore a file, first set up environment:
# 
# # su - a1-s3dup
# $ . /usr/local/etc/a1-s3dup.conf
# $ export AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY PASSPHRASE
# 
# then, if you e.g. would like to have a copy of the file
# /etc/apt/apt.conf.d/99local as it was on 2014-05-01, and you'd like to store
# this copy in /var/tmp/99local, you'd do:
#
# $ duplicity restore --file-to-restore etc/apt/apt.conf.d/99local --time 2014-05-01 $BUCKET /var/tmp/99local
#
#

CONFFILE=/usr/local/etc/a1-s3dup.conf

if test -f $CONFFILE
then
  . $CONFFILE
else
  echo >&2 "a1-s3dup: error: configuration file $CONFFILE missing"
  exit 1
fi

# these should be set in $CONFFILE
export AWS_ACCESS_KEY_ID AWS_SECRET_ACCESS_KEY PASSPHRASE
export BUCKET

dirs=$( cat <<EOT
/etc
/home
/usr/local
/root
/srv
/var/backups
/var/lib
/var/www
EOT
)

INCLUDES=
for d in $dirs
do
  INCLUDES="$INCLUDES --include $d"
done

duplicity --full-if-older-than 30D $INCLUDES --exclude '**' / $BUCKET | logger --id --priority local1.info --tag a1-dup

# do not keep backups forever
duplicity --force remove-older-than 2M $BUCKET | logger --id --priority local1.info --tag a1-dup