snap-sync: support dryrun, and selection of mounted target subvolume

- introduce commandline option --dry-run
  perform a trial run where no changes are made.
- introduce option --TARGET
  Specify the mountpoint of the BTRFS subvolume to back up to.
  This makes it possible, to have multiple subvolumes on target disks,
  and select them as needed to store backup configurations.

Signed-off-by: Ralf Zerres <ralf.zerres@networkx.de>
This commit is contained in:
2017-11-09 11:56:41 +01:00
parent 4b6a06f885
commit b973e3e0a8

View File

@@ -39,9 +39,9 @@ systemd-cat -t "$progname" < $PIPE &
exec 3>$PIPE
# global variables
#disk_uuid_$i
disk_count=-1
disk_uuid_match_count=0
disk_target_match_count=0
disk_uuid_match=''
selected_uuid='none'
selected_target='none'
@@ -60,6 +60,8 @@ check_prerequisites () {
which tee >/dev/null 2>&1 || { echo "'tee' is not installed." && exit 1; }
which btrfs >/dev/null 2>&1 || { echo "'btrfs' is not installed." && exit 1; }
which findmnt >/dev/null 2>&1 || { echo "'findmnt' is not installed." && exit 1; }
which systemd-cat >/dev/null 2>&1 || { echo "'systemd-cat' is not installed." && exit 1; }
which wc >/dev/null 2>&1 || { echo "'wc' is not installed." && exit 1; }
which notify-send >/dev/null 2>&1 || { echo "'notify-send' is not installed." && exit 1; }
if [ $(id -u) -ne 0 ] ; then echo "Script must be run as root" ; exit 1 ; fi
@@ -89,9 +91,11 @@ get_disk_infos () {
exclude_uuid=$(findmnt --noheadings --nofsroot --types btrfs --target / --output UUID)
disk_uuids=$($ssh findmnt --noheadings --nofsroot --types btrfs --output UUID,TARGET --list | grep -v $exclude_uuid | awk '{print $1}')
disk_targets=$($ssh findmnt --noheadings --nofsroot --types btrfs --output UUID,TARGET --list | grep -v $exclude_uuid | awk '{print $2}')
fs_options=$($ssh findmnt --noheadings --nofsroot --types btrfs --output UUID,OPTIONS --list | grep -v $exclude_uuid | awk '{print $2}')
else
disk_uuids=$($ssh findmnt --noheadings --nofsroot --types btrfs --output UUID --list)
disk_targets=$($ssh findmnt --noheadings --nofsroot --types btrfs --output UUID,TARGET --list)
disk_targets=$($ssh findmnt --noheadings --nofsroot --types btrfs --output TARGET --list)
fs_options=$($ssh findmnt --noheadings --nofsroot --types btrfs --output UUID,OPTIONS --list | awk '{print $2}')
fi
# we need at least one target disk
@@ -102,8 +106,10 @@ get_disk_infos () {
# Pseudo-Arrays (assumption: equal number of members)
# Pseudo-Array: disk_uuid_$i
# Pseudo-Array: disk_target_$i
# Pseudo-Array: fs_options_$i
# Pseudo-Array: disk_selected_$y (reference to $i element)
# List: disk_uuid_match (reference to matching preselected uuids)
# List: disk_target_match (reference to matching preselected targets)
# initialize our structures
i=0
@@ -122,12 +128,22 @@ get_disk_infos () {
done
i=0
for disk_target in $disk_targets; do
if [ "$disk_target" = "$target_cmdline" ]; then
disk_target_match="$i"
disk_target_match_count=$(($disk_target_match_count+1))
fi
eval "disk_target_$i='$disk_target'"
i=$((i+1))
done
i=0
for fs_option in $fs_options; do
eval "fs_options_$i='$fs_option'"
i=$((i+1))
done
}
notify () {
# estimation: batch calls should just log
if [ nonotify ]; then
printf "%s %s\n" "$progname" "$2"
else
@@ -158,40 +174,52 @@ parse_params () {
# Call usage() function.
usage
;;
-d|--description)
description="$2"
shift 2
;;
-c|--config)
selected_config="$2"
shift 2
;;
--config=*)
selected_config=${1#*=}
shift
;;
-u|--UUID)
uuid_cmdline="$2"
-d|--description)
description="$2"
shift 2
;;
--dry-run)
dryrun=1
shift 1
;;
-l|--TARGET)
target_cmdline="$2"
shift 2
;;
--UUID=*)
uuid_cmdline=${1#*=}
shift
;;
-n|--noconfirm)
noconfirm=1
nonotify=1
shift
;;
--remote)
remote=$2
ssh="ssh $remote"
-u|--UUID)
uuid_cmdline="$2"
shift 2
;;
-v|--verbose)
verbose=1
shift 1
;;
--config=*)
selected_config=${1#*=}
shift
;;
--remote)
remote=$2
ssh="ssh $remote"
shift 2
;;
--TARGET=*)
target_cmdline=${1#*=}
shift
;;
--UUID=*)
uuid_cmdline=${1#*=}
shift
;;
--) # End of all options
shift
break
@@ -220,11 +248,13 @@ parse_params () {
if [ "$verbose" ]; then
echo "Snap UUID : '$uuid_cmdline'"
echo "Snap TARGET: '$target_cmdline'"
echo "Snap Description: '$description'"
echo "Snap Config: '$selected_config'"
echo "Snap Remote: '$ssh'"
if [ "$verbose" ]; then snap_sync_options="verbose=true"; fi
if [ "$dryrun" ]; then snap_sync_options="${snap_sync_options} dry-run=true"; fi
if [ "$noconfirm" ]; then snap_sync_options="${snap_sync_options} noconfirm=true"; fi
echo "Options: ${snap_sync_options}"
fi
@@ -245,7 +275,7 @@ run_config () {
count=$(eval snapper -c $selected_config list -t single | awk '/uuid='"$selected_uuid"'/, /subvolid'="$selected_subvol"'/ {cnt++} END {print cnt}')
#count=$(eval snapper -c $selected_config list -t single | grep -c -e "subvolid=$selected_subvol" -e 'uuid=$selected_uuid')
if [ -n "$count" ] && [ "$count" -gt 1 ]; then
error "More than one snapper entry found with UUID $selected_uuid for configuration '$selected_config'. Skipping configuration '$selected_config'."
error "More than one snapper entry found with UUID $selected_uuid and SUBVOL $selected_subvol for configuration '$selected_config'. Skipping configuration '$selected_config'."
selected_configs=$(echo $selected_configs | sed -e "s/\($selected_config*\)//")
if [ "$verbose" ]; then
printf "Counter=%s" "$count"
@@ -331,15 +361,17 @@ run_config () {
else
backup_root="$selected_target/$backupdir"
fi
### Todo: if interactive, e.g use pv to show progress
printf "Please be pacient, the initial backup could take awhile.\n"
else
if [ "$verbose" ]; then
printf "Last syncronized Snapshot-ID for '%s': %s\n" "$selected_config" "$snapper_sync_id"
printf "Last syncronized Snapshot-Path for '%s': %s\n" "$selected_config" "$snapper_sync_snapshot"
fi
backupdir=$(snapper -c "$selected_config" list -t single | awk -F "|" '/'"$selected_uuid"'/ {print $5}' | awk -F "," '/backupdir/ {print $1}' | awk -F"=" '{print $2}')
backup_root="$selected_target/$backupdir"
backupdir=$(snapper -c "$selected_config" list -t single | awk -F "|" '/'"$selected_uuid"'/, /subvolid'="$selected_subvol"'/ {print $5}' | awk -F "," '/backupdir/ {print $1}' | awk -F"=" '{print $2}')
if [ -z "$backupdir" ]; then
backup_root="$selected_target"
else
backup_root="$selected_target/$backupdir"
fi
$ssh test -d $backup_root || die "%s is not a directory on %s.\n" "$backup_root" "$selected_uuid"
fi
@@ -348,20 +380,27 @@ run_config () {
if [ "$verbose" ]; then
if [ -n "$ssh" ];then
printf "Backup-Path on remote %s: %s/%s\n" "$remote" "$backup_root" "backupdir"
printf "Backup-Path on remote %s: %s/%s\n" "$remote" "$backup_root" "$backupdir"
else
printf "Backup-Path: %s/%s\n" "$backup_root" "backupdir"
printf "Backup-Path: %s/%s\n" "$backup_root" "$backupdir"
fi
fi
# acting on source system
printf "Creating new snapshot for snapper config '%s' ...\n" "$selected_config" | tee $PIPE
snapper_new_id=$(snapper -c "$selected_config" create --print-number -d "$progname backup in progress")
snapper_new_snapshot=$SUBVOLUME/.snapshots/$snapper_new_id/snapshot
snapper_new_info=$SUBVOLUME/.snapshots/$snapper_new_id/info.xml
sync
if [ ! $dryrun ]; then
printf "Creating new snapshot with snapper config '%s' ...\n" "$selected_config" | tee $PIPE
snapper_new_id=$(snapper -c "$selected_config" create --print-number -d "$progname backup in progress")
snapper_new_snapshot=$SUBVOLUME/.snapshots/$snapper_new_id/snapshot
snapper_new_info=$SUBVOLUME/.snapshots/$snapper_new_id/info.xml
sync
else
printf "dryrun: Creating new snapshot with snapper config '%s' ...\n" "$selected_config" | tee $PIPE
fi
snapper_target_snapshot=$backup_root/$selected_config/$snapper_new_id
# if we want to use snapper on the target to supervise the synced snapshots
# the backup_location needs to be in a subvol ".snapshots" inside $selected_config (hardcoded in snapper)
snapper_target_subvol=.snapshots
snapper_target_snapshot=$backup_root/$selected_config/$snapper_target_subvol/$snapper_new_id
if [ -z "$ssh" ]; then
printf "Will backup %s to %s\n" "$snapper_new_snapshot" "$snapper_target_snapshot/snapshot" | tee $PIPE
else
@@ -456,49 +495,80 @@ run_backup () {
snapper_sync_snapshot=$(eval echo \$snapper_sync_snapshot_$i)
snapper_new_snapshot=$(eval echo \$snapper_new_snapshot_$i)
snapper_new_info=$(eval echo \$snapper_new_info_$i)
snapper_target_subvol=$(eval echo \$snapper_target_subvol_$i)
snapper_target_snapshot=$(eval echo \$snapper_target_snapshot_$i)
# verify target structure for backupdir
verify_snapper_structure $backup_root $snapper_config $snapper_new_id
if [ ! "$dryrun" ]; then
verify_snapper_structure $backup_root $snapper_config $snapper_target_subvol $snapper_new_id
else
cmd="verify_snapper_structure $backup_root $snapper_config $snapper_target_subvol $snapper_new_id"
printf "dryrun: %s\n" "$cmd"
fi
if [ -z "$snapper_sync_id" ]; then
cmd="btrfs send $snapper_new_snapshot | $ssh btrfs receive $snapper_target_snapshot"
printf "Sending first snapshot for snapper config '%s'...\n" "$selected_config" | tee $PIPE
printf "Sending first snapshot for snapper config '%s' ...\n" "$selected_config" | tee $PIPE
if [ "$verbose" ]; then
printf "$cmd"
echo "btrfs send $snapper_new_snapshot | $ssh btrfs receive $snapper_target_snapshot"
cmd="btrfs send -v $snapper_new_snapshot | $ssh btrfs receive -v $snapper_target_snapshot"
fi
if [ ! "$dryrun" ]; then
btrfs send "$snapper_new_snapshot" | $ssh btrfs receive "$snapper_target_snapshot" &>/dev/null
else
cmd="btrfs send -v $snapper_new_snapshot | $ssh btrfs receive -v $snapper_target_snapshot"
printf "dryrun: %s\n" "$cmd"
fi
btrfs send "$snapper_new_snapshot" | $ssh btrfs receive "$snapper_target_snapshot" &>/dev/null
else
printf "Sending incremental snapshot for snapper config '%s'...\n" "$selected_config" | tee $PIPE
printf "Sending incremental snapshot for snapper config '%s' ...\n" "$selected_config" | 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.
cmd="btrfs send -c $snapper_sync_snapshot $snapper_new_snapshot | $ssh btrfs receive $snapper_target_snapshot"
$cmd &>/dev/null
if [ "$verbose" ]; then
printf "$cmd"
printf "Deleting sync snapshot for %s...\n" "$selected_config" | tee $PIPE
verbose_flag="-v"
if [ ! "$dryrun" ]; then
btrfs send "$verbose_flag" -c "$snapper_sync_snapshot" "$snapper_new_snapshot" | $ssh btrfs receive "$verbose_flag" "$snapper_target_snapshot"
if [ "$verbose" ]; then
printf "Deleting sync snapshot for %s ...\n" "$selected_config" | tee $PIPE
fi
snapper -c "$selected_config" delete "$snapper_sync_id"
else
printf "dryrun: btrfs send %s -c %s %s | %s btrfs receive %s %s\n" \
"$verbose_flag" "$snapper_sync_snapshot" "$snapper_new_snapshot" \
"$ssh" "$verbose_flag" "$snapper_target_snapshot"
printf "dryrun: snapper -c %s delete %a\n" "$selected_config" "$snapper_sync_id"
fi
btrfs send -c "$snapper_sync_snapshot" "$snapper_new_snapshot" | $ssh btrfs receive "$snapper_target_snapshot" &>/dev/null
snapper -c "$selected_config" delete "$snapper_sync_id"
fi
if [ -z "$ssh" ]; then
cp "$snapper_new_info" "$snapper_target_snapshot"
if [ ! "$dryrun" ]; then
cp "$snapper_new_info" "$snapper_target_snapshot"
else
cmd="cp $snapper_new_info $snapper_target_snapshot"
printf "dryrun: %s\n" "$cmd"
fi
else
rsync -avzq "$snapper_new_info" "$remote":"$snapper_target_snapshot"
if [ ! "$dryrun" ]; then
rsync -avzq "$snapper_new_info" "$remote":"$snapper_target_snapshot"
else
cmd="rsync -avzq $snapper_new_info $remote:$snapper_target_snapshot"
printf "dryrun: %s\n" "$cmd"
fi
fi
# It's important not to change the values of the key/value pairs ($userdata)
# which is stored in snappers info.xml file of the source snapshot.
# This is how we find the parent.
userdata="backupdir=$backup_dir, uuid=$selected_uuid"
userdata="backupdir=$backup_dir, uuid=$selected_uuid, subvolid=$selected_subvol"
# Tag new snapshot as the latest
printf "Tagging new snapshot as latest backup for '%s' ...\n" "$selected_config" | tee $PIPE
snapper -v -c "$selected_config" modify -d "$description" -u "$userdata" "$snapper_new_id"
if [ ! "$dryrun" ]; then
snapper -v -c "$selected_config" modify -d "$description" -u "$userdata" "$snapper_new_id"
else
cmd="snapper -v -c $selected_config modify -d $description -u $userdata $snapper_new_id"
printf "dryrun: %s\n" "$cmd"
fi
printf "Backup complete for snapper configuration '%s'.\n" "$selected_config" > $PIPE
done
@@ -511,6 +581,8 @@ select_target_disk () {
#local disk_selected_ids=''
local disk_selected_count=0
local subvolid=''
local subvol=''
# print selection table
if [ -z "$ssh" ]; then
@@ -519,6 +591,16 @@ select_target_disk () {
printf "Selecting a mounted BTRFS device for backups on %s.\n" "$remote"
fi
while [ "$disk_id" -eq -1 ] || [ "$disk_id" -le $disk_count ]; do
if [ "$disk_target_match_count" -eq 1 ]; then
# matching TARGET selection from commandline
# Pseudo-Array: disk_selected_$i (reference to $disk_uuid element)
eval "disk_selected_$i='$disk_target_match'"
disk=$(eval echo \$disk_uuid_$disk_target_match)
target=$(eval echo \$disk_target_$disk_target_match)
fs_options=$(eval echo \$fs_options_$disk_target_match | sed -e 's/.*,\(subvolid=[0-9]*\).*,\(subvol=[0-9]*\)/\1,\2/')
disk_selected=$disk_target_match
break
fi
if [ "$disk_uuid_match_count" -gt 1 ]; then
# got UUID selection from commandline
disk_count=$disk_uuid_match_count
@@ -529,8 +611,8 @@ select_target_disk () {
# Pseudo-Array: disk_selected_$i (reference to $disk_uuid element)
eval "disk_selected_$i='$disk_uuid'"
disk=$(eval echo \$disk_uuid_$disk_uuid)
target=$(eval echo \$disk_target_$disk_uuid)
printf "%4s) %s %s\n" "$i" "$disk" "$target"
fs_options=$(eval echo \$fs_options_$disk_uuid | sed -e 's/.*,\(subvolid=[0-9]*\).*,\(subvol=[0-9]*\)/\1,\2/')
printf "%4s) %s %s (%s)\n" "$i" "$disk" "$target" "$fs_options"
i=$((i+1))
done
else
@@ -540,7 +622,8 @@ select_target_disk () {
eval disk_selected_$i="$disk_id"
disk=$(eval echo \$disk_uuid_$disk_id)
target=$(eval echo \$disk_target_$disk_id)
printf "%4s) %s %s\n" "$disk_id" "$disk" "$target"
fs_options=$(eval echo \$fs_options_$disk_id | sed -e 's/.*,\(subvolid=[0-9]*\).*,\(subvol=[0-9]*\)/\1,\2/')
printf "%4s) %s %s (%s)\n" "$disk_id" "$disk" "$target" "$fs_options"
i=$((i+1))
disk_id=$(($disk_id+1))
done
@@ -572,14 +655,19 @@ select_target_disk () {
selected_uuid=$(eval echo \$disk_uuid_$disk_selected)
selected_target=$(eval echo \$disk_target_$disk_selected)
selected_subvol=$(eval echo \$fs_options_$disk_selected | sed -e 's/.*subvolid=\([0-9]*\).*/\1/')
#fs_options=$(eval echo \$fs_options_$disk_selected | sed -e 's/.*,\(subvolid=[0-9]*\).*,\(subvol=[0-9]*\)/\1,\2/')
if [ "$verbose" ]; then
printf "Selected Subvol-ID=%s: %s on %s\n" "$selected_subvol" "$selected_target" "$selected_uuid"
fi
}
traperror () {
printf "Exited due to error on line %s.\n" $1
printf "exit status: %s\n" "$2"
printf "command: %s\n" "$3"
printf "bash line: %s\n" "$4"
printf "function name: %s\n" "$5"
#printf "command: %s\n" "$3"
#printf "bash line: %s\n" "$4"
#printf "function name: %s\n" "$5"
exit 1
}
@@ -587,10 +675,6 @@ trapkill () {
die "Exited due to user intervention."
}
# bashism
#trap 'traperror ${LINENO} $? "$BASH_COMMAND" $BASH_LINENO "${FUNCNAME[@]}"' ERR
#trap trapkill SIGTERM SIGINT
usage () {
cat <<EOF
$progname $version
@@ -605,9 +689,11 @@ Options:
directory name on first backup"
-u, --UUID <UUID> Specify the UUID of the mounted BTRFS subvolume to back up to. Otherwise will prompt."
If multiple mount points are found with the same UUID, will prompt user."
--remote <address> Send the snapshot backup to a remote machine. The snapshot will be sent via ssh. You
should specify the remote machine's hostname or ip address. The 'root' user must be
-l, --TARGET <target> Specify the mountpoint of the BTRFS subvolume to back up to.
--remote <address> Send the snapshot backup to a remote machine. The snapshot will be sent via ssh. You
should specify the remote machine's hostname or ip address. The 'root' user must be
permitted to login on the remote machine.
--dry-run perform a trial run where no changes are made.
-v, --verbose Be more verbose on what's going on.
EOF
@@ -618,7 +704,8 @@ EOF
verify_snapper_structure () {
local backup_root=$1
local snapper_config=$2
local snapper_id=$3
local snapper_subvol=$3
local snapper_id=$4
if [ "$verbose" ]; then
echo "Verify snapper filesystem structure on target ..."
@@ -632,11 +719,26 @@ verify_snapper_structure () {
$ssh mkdir --mode=0700 --parents $backup_root/$snapper_config
fi
if $ssh [ ! -d $backup_root/$snapper_config/$snapper_id ]; then
# if not accessible, create subvolume to hold snappers snapshot structure
create_subvol="btrfs subvolume create $backup_root/$snapper_config/$snapper_subvol"
# check if given snapper_subvol is a subvol
if $ssh [ ! -d $backup_root/$snapper_config/$snapper_subvol ]; then
if [ "$verbose" ]; then
echo "Create backup-path $backup_root/$snapper_config/$snapper_id"
echo "Create new subvolume $backup_root/$snapper_config/$snapper_subvol"
fi
$ssh mkdir --mode=0700 $backup_root/$snapper_config/$snapper_id
$ssh $create_subvol || die "BTRFS subvolume %s to hold snapshots for config %s could not be created in directory on %s.\n" "$snapper_subvol" "$snapper_config" "$backup_root"
else
if $ssh [ `stat --format=%i $backup_root/$snapper_config/$snapper_subvol` -ne 256 ]; then
die "%s needs to be a BTRFS subvolume. But given %s is just a directory.\n" "$snapper_subvol" "$backup_root/$snapper_config/$snapper_subvol"
fi
fi
if $ssh [ ! -d $backup_root/$snapper_config/$snapper_subvol/$snapper_id ]; then
if [ "$verbose" ]; then
echo "Create backup-path $backup_root/$snapper_config/$snapper_subvol/$snapper_id"
fi
$ssh mkdir --mode=0700 $backup_root/$snapper_config/$snapper_subvol/$snapper_id
fi
}
@@ -647,6 +749,11 @@ verify_snapper_structure () {
cwd=`pwd`
ssh=""
# this bashism has to be adapted
#trap 'traperror ${LINENO} $? "$BASH_COMMAND" $BASH_LINENO "${FUNCNAME[@]}"' ERR
trap 'traperror ${LINENO} $?"' ERR
trap trapkill SIGTERM SIGINT
parse_params $@
check_prerequisites
@@ -654,14 +761,20 @@ check_prerequisites
# read mounted BTRFS structures
get_disk_infos
if [ "$uuid_cmdline" != "none" ]; then
if [ "target_cmdline" != "none" ]; then
if [ -z "$ssh" ]; then
notify_info "Backup started" "Starting backups to '$target_cmdline' ..."
else
notify_info "Backup started" "Starting backups to '$target_cmdline' at $remote ..."
fi
elif [ "$uuid_cmdline" != "none" ]; then
if [ -z $ssh ]; then
notify_info "Backup started" "Starting backups to $uuid_cmdline..."
else
notify_info "Backup started" "Starting backups to $uuid_cmdline at $remote..."
fi
else
if [ -z $ssh ]; then
if [ -z "$ssh" ]; then
notify_info "Backup started" "Starting backups. Use command line menu to select disk."
else
notify_info "Backup started" "Starting backups. Use command line menu to select disk on $remote."
@@ -672,7 +785,7 @@ fi
select_target_disk
printf "\nYou selected the disk with UUID %s.\n" "$selected_uuid" | tee $PIPE
if [ -z $ssh ]; then
if [ -z "$ssh" ]; then
printf "The disk is mounted at %s.\n" "$selected_target" | tee $PIPE
else
printf "The disk is mounted at %s:%s.\n" "$remote" "$selected_target" | tee $PIPE