LXC LVM volume backup script using duplicity

lxc-lvm-duplicity_backup.sh

#! /bin/bash -e

#
## LVM backup script by Hendrik 'Sharky' Schumann
#

GROUP="vg0"
VOLUMES="lxc-xana lxc-githost"
BACKDIR="/mnt/autoback"


# Duplicity settings
DUPLICITY="/usr/local/bin/duplicity"
DEST="b2://...changeme..."

DUPLICITY_OPTIONS="-v5 --full-if-older-than 1M --asynchronous-upload"
DUPLICITY_EXCLUDE="--exclude /dev/ --exclude /sys/ --exclude /var/lib/lxcfs --exclude /proc/ --exclude /run/ --exclude /tmp/"

# Extra excludes example
#DUPLICITY_EXCLUDE="$DUPLICITY_EXCLUDE --exclude $BACKDIR/lxc-somecontainer-autoback/home/someuser"

# Duplicity key
DUPLICITY_KEY="BADBABE"
. /root/.duplicity
export PASSPHRASE


function is_autoback {
	if [[ "$V1" == *"-autoback" ]]; then
		return 1
	fi
	return 0
}

function create_snapshot {
	V="$1"
	lvcreate -L512M -s -n "$V-autoback" /dev/$GROUP/$V
	return $?
}

function mount_snapshot {
	V="$1"
	SNAPNAME="$V-autoback"
	mkdir -p $BACKDIR/$SNAPNAME || true
	
	mount /dev/$GROUP/$SNAPNAME $BACKDIR/$SNAPNAME -o ro
	return $?
}

function unmount_and_destroy_snapshot {
	V="$1"
	SNAPNAME="$V-autoback"
	FORCE="$2"
	
	if [[ "x$FORCE" != "x" ]]; then
		umount $BACKDIR/$SNAPNAME || true
		lvremove -f /dev/$GROUP/$SNAPNAME || true
	else
		umount $BACKDIR/$SNAPNAME
		lvremove -f /dev/$GROUP/$SNAPNAME
	fi
	return $?
}

trap ctrl_c INT

function ctrl_c() {
	echo " *** Trapped CTRL-C"
	for V in $VOLUMES; do
		unmount_and_destroy_snapshot $V force
	done
	exit 1
}

for V in $VOLUMES; do
	echo " - $V"
	
	create_snapshot $V
	SNAPNAME="$V-autoback"
	
	mount_snapshot $V
	#du -hs $BACKDIR/$SNAPNAME
done

echo " * Invoking duplicity"
##
# everything mounted, invoke duplicity
##

"$DUPLICITY" $DUPLICITY_OPTIONS $DUPLICITY_EXCLUDE --encrypt-sign-key $DUPLICITY_KEY / "$DEST"
"$DUPLICITY" -vn remove-all-but-n-full 3 --force "$DEST"

echo " * Cleaning up autoback snapshots"

for V in $VOLUMES; do
	unmount_and_destroy_snapshot $V
done