iankelling.org Git - distro-setup/blob - btrbk-run

   1 #!/bin/bash
   2 # Copyright (C) 2016 Ian Kelling
   3
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16
  17 # todo: if we cancel in the middle of a btrfs send, then run again immediately, the received subvolume doesn't get a Received UUID: field, and we won't mount it. Need to figure out a solution that will fix this.
  18
  19 set -eE -o pipefail
  20 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  21
  22 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  23
  24 usage() {
  25   cat <<'EOF'
  26 btrbk-run [OPTIONS]
  27 usually -t TARGET_HOST or -s SOURCE_HOST
  28
  29 Note, at source location, intentionally not executable, run and read
  30 install-my-scripts.
  31
  32 EOF
  33   echo "top of script file:"
  34   sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  35   exit $1
  36 }
  37
  38 script_dir=$(dirname $(readlink -f "$BASH_SOURCE"))
  39
  40 # note q is owned by root:1000
  41 # note p/m is owned 1000:1000 and chmod 700
  42
  43
  44 mountpoints=()
  45
  46 rsync_mountpoint=/q
  47
  48 # default options
  49 conf_only=false
  50 dry_run=false # mostly for testing
  51 rate_limit=no
  52 verbose=true; verbose_arg=-v
  53 progress_arg="--progress"
  54
  55 default_args_file=/etc/btrbk-run.conf
  56 if [[ -s $default_args_file ]]; then
  57   set -- $(< $default_args_file) "$@"
  58 fi
  59
  60 temp=$(getopt -l help cl:m:nps:t:vh "$@") || usage 1
  61 eval set -- "$temp"
  62 while true; do
  63   case $1 in
  64     # only creates the config file, does not run btrbk
  65     -c) conf_only=true; shift ;;
  66     # bytes per second, suffix k m g
  67     -l) rate_limit=$2; shift 2 ;;
  68     # Comma separated mountpoints to backup. This has defaults set below.
  69     -m) IFS=, mountpoints=($2); unset IFS; shift 2 ;;
  70     -n) dry_run=true; dry_run_arg=-n; shift ;;
  71     -p) progress_arg="--progress"; shift ;;
  72     -q) verbose=false; verbose_arg=; progress_arg=; shift ;;
  73     # source host to receive a backup from
  74     -s) source=$2; shift 2 ;;
  75     # target hosts to send to. empty is valid for just doing local
  76     # snapshot. we have default hosts we will populate.
  77     -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  78     -v) verbose=true; verbose_arg=-v; shift ;;
  79     -h|--help) usage ;;
  80     --) shift; break ;;
  81     *) echo "$0: Internal error!" ; exit 1 ;;
  82   esac
  83 done
  84
  85 # usefull commands are resume and archive
  86 cmd_arg=${1:-run}
  87
  88 if [[ -s $default_args_file ]]; then
  89   echo "$0: warning: default btrbk-run options set in $default_args_file (sleeping 5 seconds):"
  90   cat $default_args_file
  91   sleep 5
  92 fi
  93
  94 if [[ -v targets && $source ]]; then
  95   echo "$0: error: -t and -s are mutually exclusive" >&2
  96   exit 1
  97 fi
  98
  99 echo -e "$0: options: conf_only=$conf_only\ndry_run=$dry_run\nrate_limit=$rate_limit\nverbose=$verbose\ncmd_arg=$cmd_arg"
 100
 101 # set default targets
 102 if [[ ! -v targets && ! $source ]]; then
 103   case $HOSTNAME in
 104     x2|kw)
 105       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 106         targets=($HOME_DOMAIN)
 107       fi
 108       ;;
 109     tp)
 110       targets=(frodo)
 111       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 112         if timeout -s 9 10 ssh x2 :; then
 113           targets+=(x2)
 114         fi
 115       fi
 116       ;;
 117     frodo)
 118       targets=()
 119       ;;
 120     *)
 121       echo "$0: error: no default targets for this host, use -t"
 122       exit 1
 123       ;;
 124   esac
 125 fi
 126
 127 if [[ -v targets ]]; then
 128   echo "targets: ${targets[*]}"
 129 fi
 130
 131 if [[ $source ]]; then
 132   echo "source: $source"
 133 fi
 134
 135
 136
 137 # set default mountpoints
 138 case $HOSTNAME in
 139   # no remote backups atm. note, if we do enable this, configuration below will need some changes.
 140   #  frodo)
 141   #    prospective_mps=(/i)
 142   #    ;;
 143   *)
 144     prospective_mps=(/a /q)
 145     if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 146       prospective_mps+=(/o)
 147     fi
 148     ;;
 149 esac
 150 case ${targets[0]} in
 151   kw|kww)
 152     prospective_mps=(/a)
 153     ;;
 154 esac
 155
 156 for mp in ${prospective_mps[@]}; do # default mountpoints to sync
 157   if [[ -e /nocow/btrfs-stale/$mp ]]; then
 158     echo "$0: warning: $mp stale, not adding to default mountpoints"
 159     continue
 160   fi
 161   if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
 162     mountpoints+=($mp)
 163   fi
 164 done
 165
 166 echo "mountpoints: ${mountpoints[*]}"
 167
 168 ##### end command line parsing ########
 169
 170 rsync-dirs() {
 171   local host=$1
 172   local path=$2
 173   m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 174 }
 175
 176
 177 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
 178
 179
 180 if ! which btrbk &>/dev/null; then
 181   echo "$0: error: no btrbk binary found"
 182   exit 1
 183 fi
 184 # if our mountpoints are from stale snapshots,
 185 # it doesn't make sense to do a backup.
 186 check-subvol-stale ${mountpoints[@]} || exit 1
 187
 188
 189 cat >/etc/btrbk.conf <<EOF
 190 ssh_identity /root/.ssh/home
 191 # Just a guess that local7 is a good facility to pick.
 192 # It's a bit odd that the transaction log has to be logged to
 193 # a file or syslog, while other output is sent to std out.
 194 # The man does not mention a way for them to be together, but
 195 # I dunno if setting a log level like warn might also output
 196 # transaction info.
 197 transaction_syslog local7
 198
 199 # 20%ish speedup[]
 200 stream_buffer 512m
 201
 202 # so we only run one at a time
 203 lockfile                   /var/lock/btrbk.lock
 204
 205 # default format of short does not accomidate hourly preservation setting
 206 timestamp_format long-iso
 207
 208 # only make a snapshot if things have changed
 209 snapshot_create onchange
 210 # I could make this different from target_preserve,
 211 # if one disk had less space.
 212 # for now, keeping them equal.
 213 snapshot_preserve 36h 14d 8w 24m
 214 snapshot_preserve_min 4h
 215 snapshot_dir btrbk
 216
 217 # so, total backups = ~89
 218 target_preserve 36h 14d 8w 24m
 219 target_preserve_min 4h
 220
 221 # if something fails and it's not obvious, try doing
 222 # btrbk -l debug -v dryrun
 223
 224 rate_limit $rate_limit
 225 EOF
 226
 227
 228
 229 for tg in ${targets[@]:-$HOSTNAME}; do
 230   # for an initial run, btrbk requires the dir to exist.
 231   ssh root@$tg mkdir -p /mnt/root/btrbk
 232 done
 233
 234
 235
 236 vol=/mnt/root
 237 for m in ${mountpoints[@]}; do
 238   sub=${m##*/}
 239   if [[ $source ]]; then
 240     cat >>/etc/btrbk.conf <<EOF
 241 volume ssh://$source$vol
 242 subvolume $sub
 243 target send-receive $vol/btrbk
 244 EOF
 245   else
 246     cat >>/etc/btrbk.conf <<EOF
 247 volume $vol
 248 subvolume $sub
 249 EOF
 250     for tg in ${targets[@]}; do
 251       cat >>/etc/btrbk.conf <<EOF
 252 target send-receive ssh://$tg$vol/btrbk
 253 EOF
 254     done
 255   fi
 256 done
 257
 258
 259 # todo: umount first to ensure we don't have any errors
 260 # todo: do some kill fuser stuff to make umount more reliable
 261
 262
 263 if $conf_only; then
 264   exit
 265 fi
 266
 267
 268
 269 if $dry_run; then
 270   m btrbk -v -n $cmd_arg
 271 elif [[ $cmd_arg == archive ]]; then
 272   if [[ $source ]]; then
 273     m btrbk $verbose_arg $progress_arg $cmd_arg ssh://$source$vol $vol
 274   else
 275     for tg in ${targets[@]}; do
 276       m btrbk $verbose_arg $progress_arg $cmd_arg $vol ssh://$tg$vol
 277     done
 278   fi
 279   exit 0
 280 fi
 281 # -q and just using the syslog option seemed nice,
 282 # but it doesn't show when a send has a parent and when it doesn't.
 283 m btrbk $verbose_arg $progress_arg $cmd_arg
 284
 285 # if we have it, sync to systems which don't
 286 if mountpoint $rsync_mountpoint >/dev/null; then
 287   for tg in ${targets[@]}; do
 288     case $tg in
 289       li|lk)
 290         for x in /p/c/machine_specific/*.hosts; do
 291           if grep -qxF $tg $x; then
 292             dir=${x%.hosts}
 293             rsync-dirs $tg $dir
 294           fi
 295         done
 296         ;;
 297     esac
 298   done
 299 fi
 300
 301 PATH=$script_dir:$PATH
 302 if [[ $source ]]; then
 303   m mount-latest-subvol
 304 else
 305   m mount-latest-remote ${targets[@]}
 306 fi
 307
 308 # todo: move variable data we don't care about backing up
 309 # to /nocow and symlink it.
 310
 311
 312 # background on btrbk timezones. with short/long, timestamps use local time.
 313 # for long, if your local time moves backwards, by moving timezones or
 314 # for an hour when daylight savings changes it, you will temporarily get
 315 # a more aggressive retention policy for the overlapping period, and
 316 # vice versa for the opposite timezone move. The alternative is using
 317 # long-iso, which puts timezone info into the timestamp, which means
 318 # that instead of shifting time, you shift the start of day/week/month
 319 # which is used for retention to your new local time, which means for
 320 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 321 # retention will be 8 hours more aggressive since midnight is at a new
 322 # time, unless you fake the timzeone using the TZ env variable.
 323 # However, in the short term, there will be no inconsistencies.
 324 # I don't see any problem with shifting when the day starts for
 325 # retention, so I'm using long-iso.
 326
 327 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z