Files
dsnap-sync/bin/snap-sync
James Barnett 35c6cf6f97 formatting
2017-02-02 19:36:44 -06:00

339 lines
11 KiB
Bash
Executable File

#!/bin/bash
# James W. Barnett
# Takes snapshots of each snapper configuration. It then sends the snapshot to
# a location on an external drive. After the initial transfer, it does
# incremental snapshots on later calls. It's important not to delete the
# snapshot created on your system since that will be used to determine the
# difference for the next incremental snapshot.
version="0.3"
name="snap-sync"
function error_exit
{
for u in $(users); do
notify_cmd="sudo -u $u DISPLAY=:0 DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(sudo -u $u id -u)/bus notify-send"
$notify_cmd -a $name 'Error' 'Check journal for more information.' --icon=dialog-error
done
printf "\nExited due to error.\n" | tee $PIPE
exit 1
}
function kill_exit
{
printf "\nExited due to user intervention.\n" | tee $PIPE
exit 1
}
trap error_exit ERR
trap kill_exit SIGTERM SIGINT
while [[ $# -gt 0 ]]; do
key="$1"
case $key in
-d|--description)
description="$2"
shift 2
;;
-c|--config)
selected_configs="$2"
shift 2
;;
-u|--UUID)
uuid_cmdline="$2"
shift 2
;;
-n|--noconfirm)
noconfirm="yes"
shift
;;
-h|--help)
printf "$name $version\n\n"
printf "Usage: $name [options]\n\n"
printf "Options:\n"
printf " -d, --description <desc> Change the snapper description. Default: \"latest incremental backup\"\n"
printf " -c, --config <config> Specify the snapper configuration to use. Otherwise will perform for each snapper\n"
printf " configuration. Can list multiple configurations within quotes, space-separated\n"
printf " (e.g. -c \"root home\").\n"
printf " -n, --noconfirm Do not ask for confirmation for each configuration. Will still prompt for backup\n"
printf " directory name on first backup\n"
printf " -u, --UUID <UUID> Specify the UUID of the mounted BTRFS subvolume to back up to. Otherwise will prompt.\n"
printf " If multiple mount points are found with the same UUID, will prompt user.\n"
exit 1
;;
*)
printf "ERROR: Unknown option: $key\n"
printf "Run '$name -h' for valid options.\n"
exit 1
;;
esac
done
description=${description:-"latest incremental backup"}
uuid_cmdline=${uuid_cmdline:-"none"}
noconfirm=${noconfirm:-"no"}
for u in $(users); do
notify_cmd="sudo -u $u DISPLAY=:0 DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(sudo -u $u id -u)/bus notify-send"
if [[ "$uuid_cmdline" != "none" ]]; then
$notify_cmd -a $name 'Backup started' 'Starting backups to '$uuid_cmdline'...' --icon=dialog-information
else
$notify_cmd -a $name 'Backup started' 'Starting backups. Use command line menu to select disk.' --icon=dialog-information
fi
done
if [[ $EUID -ne 0 ]]; then
printf "Script must be run as root.\n"
exit
fi
TMPDIR=$(mktemp -d)
PIPE=$TMPDIR/$name.out
mkfifo $PIPE
systemd-cat -t "$name" < $PIPE &
exec 3>$PIPE
TARGETS="$(findmnt -n -v -t btrfs -o TARGET --list)"
UUIDS="$(findmnt -n -v -t btrfs -o UUID --list)"
declare -a TARGETS_ARRAY
declare -a UUIDS_ARRAY
i=0
disk=-1
disk_count=0
for x in $UUIDS; do
UUIDS_ARRAY[$i]=$x
if [[ "$x" == "$uuid_cmdline" ]]; then
disk=$i
disk_count=$(($disk_count+1))
fi
i=$((i+1))
done
i=0
for x in $TARGETS; do
TARGETS_ARRAY[$i]=$x
i=$((i+1))
done
if [[ "$disk_count" > 1 ]]; then
printf "Multiple mount points were found with UUID $uuid_cmdline.\n"
disk="-1"
fi
if [[ "$disk" == -1 ]]; then
if [[ "$disk_count" == 0 && "$uuid_cmdline" != "none" ]]; then
printf "ERROR: A device with UUID $uuid_cmdline was not found to be mounted, or it is not a BTRFS device.\n"
for u in $(users); do
notify_cmd="sudo -u $u DISPLAY=:0 DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(sudo -u $u id -u)/bus notify-send"
$notify_cmd -a $name 'Error' 'No disk with '$uuid_cmdline' mounted.' --icon=dialog-error
done
fi
printf "Select a mounted BTRFS device to backup to.\n"
while [[ $disk -lt 0 || $disk -gt $i ]]; do
for x in "${!TARGETS_ARRAY[@]}"; do
printf "%4s) %s (%s)\n" "$((x+1))" "${UUIDS_ARRAY[$x]}" "${TARGETS_ARRAY[$x]}"
done
printf "%4s) Exit\n" "0"
read -r -p "Enter a number: " disk
done
if [[ $disk == 0 ]]; then
exit 0
fi
disk=$(($disk-1))
fi
selected_uuid="${UUIDS_ARRAY[$((disk))]}"
selected_mnt="${TARGETS_ARRAY[$((disk))]}"
printf "\nYou selected the disk with UUID %s.\n" "$selected_uuid" | tee $PIPE
printf "The disk is mounted at %s.\n" "$selected_mnt" | tee $PIPE
if [[ -f /etc/conf.d/snapper ]]; then
source /etc/conf.d/snapper
else
printf "ERROR: /etc/conf.d/snapper does not exist!\n" | tee $PIPE
error_exit
fi
selected_configs=${selected_configs:-$SNAPPER_CONFIGS}
declare -a BACKUPDIRS_ARRAY
declare -a MYBACKUPDIR_ARRAY
declare -a OLD_NUM_ARRAY
declare -a OLD_SNAP_ARRAY
declare -a NEW_NUM_ARRAY
declare -a NEW_SNAP_ARRAY
declare -a NEW_INFO_ARRAY
declare -a BACKUPLOC_ARRAY
declare -a CONT_BACKUP_ARRAY
printf "\nInitial configuration...\n" | tee $PIPE
# Initial configuration of where backup directories are
i=0
for x in $selected_configs; do
if [[ "$(sudo snapper -c $x list -t single | awk '/'$name' backup in progress/ {cnt++} END {print cnt}')" -gt 0 ]]; then
printf "\nNOTE: Previous failed $name backup snapshots found for '$x'.\n" | tee $PIPE
fi
SNAP_SYNC_EXCLUDE=no
if [[ -f "/etc/snapper/configs/$x" ]]; then
source /etc/snapper/configs/$x
else
printf "ERROR: Selected snapper configuration $x does not exist.\n"
error_exit
fi
if [[ $SNAP_SYNC_EXCLUDE == "yes" ]]; then
continue
fi
printf "\n"
old_num=$(snapper -c "$x" list -t single | awk '/'"$selected_uuid"'/ {print $1}')
old_snap=$SUBVOLUME/.snapshots/$old_num/snapshot
OLD_NUM_ARRAY[$i]=$old_num
OLD_SNAP_ARRAY[$i]=$old_snap
if [[ -z "$old_num" ]]; then
printf "No backups have been performed for '%s' on this disk.\n" "$x"
read -r -p "Enter name of directory to store backups, relative to $selected_mnt (to be created if not existing): " mybackupdir
printf "This will be the initial backup for snapper configuration '%s' to this disk. This could take awhile.\n" "$x"
BACKUPDIR="$selected_mnt/$mybackupdir"
mkdir -p -m700 "$BACKUPDIR"
else
mybackupdir=$(snapper -c root list -t single | awk -F"|" '/'"$selected_uuid"'/ {print $5}' | awk -F "," '/backupdir/ {print $1}' | awk -F"=" '{print $2}')
BACKUPDIR="$selected_mnt/$mybackupdir"
if [[ ! -d $BACKUPDIR ]]; then
printf "ERROR: %s is not a directory on %s.\n" "$BACKUPDIR" "$selected_uuid" | tee $PIPE
error_exit
fi
fi
BACKUPDIRS_ARRAY[$i]="$BACKUPDIR"
MYBACKUPDIR_ARRAY[$i]="$mybackupdir"
printf "Creating new snapshot for $x...\n" | tee $PIPE
new_num=$(snapper -c "$x" create --print-number -d "$name backup in progress")
new_snap=$SUBVOLUME/.snapshots/$new_num/snapshot
new_info=$SUBVOLUME/.snapshots/$new_num/info.xml
sync
backup_location=$BACKUPDIR/$x/$new_num/
printf "Will backup %s to %s\n" "$new_snap" "$backup_location/snapshot" | tee $PIPE
NEW_NUM_ARRAY[$i]="$new_num"
NEW_SNAP_ARRAY[$i]="$new_snap"
NEW_INFO_ARRAY[$i]="$new_info"
BACKUPLOC_ARRAY[$i]="$backup_location"
cont_backup="K"
CONT_BACKUP_ARRAY[$i]="yes"
if [[ $noconfirm == "yes" ]]; then
cont_backup="yes"
else
while [[ -n "$cont_backup" && "$cont_backup" != [Yy]"es" &&
"$cont_backup" != [Yy] && "$cont_backup" != [Nn]"o" &&
"$cont_backup" != [Nn] ]]; do
read -r -p "Continue with backup [Y/n]? " cont_backup
if [[ -n "$cont_backup" && "$cont_backup" != [Yy]"es" &&
"$cont_backup" != [Yy] && "$cont_backup" != [Nn]"o" &&
"$cont_backup" != [Nn] ]]; then
printf "Select 'Y' or 'n'.\n"
fi
done
fi
if [[ "$cont_backup" != [Yy]"es" && "$cont_backup" != [Yy] && -n "$cont_backup" ]]; then
CONT_BACKUP_ARRAY[$i]="no"
printf "Aborting backup for this configuration.\n"
snapper -c $x delete $new_num
fi
i=$(($i+1))
done
# Actual backing up
printf "\nPerforming backups...\n" | tee $PIPE
i=-1
for x in $selected_configs; do
i=$(($i+1))
SNAP_SYNC_EXCLUDE=no
if [[ -f "/etc/snapper/configs/$x" ]]; then
source /etc/snapper/configs/$x
else
printf "ERROR: Selected snapper configuration $x does not exist.\n"
error_exit
fi
cont_backup=${CONT_BACKUP_ARRAY[$i]}
if [[ $cont_backup == "no" || $SNAP_SYNC_EXCLUDE == "yes" ]]; then
$notify_cmd -a $name 'Backup in progress' 'Skipping '$x' configuration.' --icon=dialog-information
continue
fi
$notify_cmd -a $name 'Backup in progress' 'Backing up '$x' configuration.' --icon=dialog-information
printf "\n"
old_num="${OLD_NUM_ARRAY[$i]}"
old_snap="${OLD_SNAP_ARRAY[$i]}"
BACKUPDIR="${BACKUPDIRS_ARRAY[$i]}"
mybackupdir="${MYBACKUPDIR_ARRAY[$i]}"
new_num="${NEW_NUM_ARRAY[$i]}"
new_snap="${NEW_SNAP_ARRAY[$i]}"
new_info="${NEW_INFO_ARRAY[$i]}"
backup_location="${BACKUPLOC_ARRAY[$i]}"
mkdir -p "$backup_location"
if [[ -z "$old_num" ]]; then
printf "Sending first snapshot for %s...\n" "$x" | tee $PIPE
btrfs send "$new_snap" | btrfs receive "$backup_location" &>/dev/null
else
printf "Sending incremental snapshot for %s...\n" "$x" | tee $PIPE
# Sends the difference between the new snapshot and old snapshot to the
# backup location. Using the -c flag instead of -p tells it that there
# is an identical subvolume to the old snapshot at the receiving
# location where it can get its data. This helps speed up the transfer.
btrfs send "$new_snap" -c "$old_snap" | btrfs receive "$backup_location" &>/dev/null
printf "Deleting old snapshot for $x...\n" | tee $PIPE
snapper -c "$x" delete "$old_num"
fi
cp "$new_info" "$backup_location"
# It's important not to change this userdata in the snapshots, since that's how
# we find the previous one.
userdata="backupdir=$mybackupdir, uuid=$selected_uuid"
# Tag new snapshot as the latest
printf "Tagging new snapshot as latest backup for $x...\n" | tee $PIPE
snapper -v -c "$x" modify -d "$description" -u "$userdata" "$new_num"
printf "Backup complete for configuration %s.\n" "$x" > $PIPE
done
printf "\nDone!\n" | tee $PIPE
exec 3>&-
for u in $(users); do
notify_cmd="sudo -u $u DISPLAY=:0 DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(sudo -u $u id -u)/bus notify-send"
if [[ "$uuid_cmdline" != "none" ]]; then
$notify_cmd -a $name 'Finished' 'Backups to '$uuid_cmdline' complete!' --icon=dialog-information
else
$notify_cmd -a $name 'Finished' 'Backups complete!' --icon=dialog-information
fi
done