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   echo "top of script file:"
  26   sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  27   exit $1
  28 }
  29
  30 script_dir=$(dirname $(readlink -f "$BASH_SOURCE"))
  31
  32 # note q is owned by root:1000
  33 # note p/m is owned 1000:1000 and chmod 700
  34
  35
  36 mountpoints=()
  37
  38 rsync_mountpoint=/q
  39
  40 conf_only=false
  41 dry_run=false # mostly for testing
  42 rate_limit=no
  43 verbose=false
  44
  45 default_args_file=/etc/btrbk-run.conf
  46 if [[ -s $default_args_file ]]; then
  47   set -- $(< $default_args_file) "$@"
  48 fi
  49
  50 temp=$(getopt -l help cl:m:npt:vh "$@") || usage 1
  51 eval set -- "$temp"
  52 while true; do
  53   case $1 in
  54     # only creates the config file, does not run btrbk
  55     -c) conf_only=true; shift ;;
  56     # bytes per second, suffix k m g
  57     -l) rate_limit=$2; shift 2 ;;
  58     # Comma separated mountpoints to backup. This has defaults set below.
  59     -m) IFS=, mountpoints=($2); unset IFS; shift 2 ;;
  60     -n) dry_run=true; dry_run_arg=-n; shift ;;
  61     -p) progress_arg="--progress"; shift ;;
  62     # target hosts to send to. empty is valid for just doing local
  63     # snapshot. we have default hosts we will populate.
  64     -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  65     -v) verbose=true; verbose_arg=-v; shift ;;
  66     -h|--help) usage ;;
  67     --) shift; break ;;
  68     *) echo "$0: Internal error!" ; exit 1 ;;
  69   esac
  70 done
  71
  72 # usefull commands are resume and archive
  73 cmd_arg=${1:-run}
  74
  75 if [[ -s $default_args_file ]]; then
  76   echo "$0: warning: default btrbk-run options set in $default_args_file (sleeping 5 seconds):"
  77   cat $default_args_file
  78   sleep 5
  79 fi
  80
  81 echo -e "$0: options: conf_only=$conf_only\ndry_run=$dry_run\nrate_limit=$rate_limit\nverbose=$verbose\ncmd_arg=$cmd_arg"
  82
  83 # set default targets
  84 if [[ ! -v targets ]]; then
  85   case $HOSTNAME in
  86     x2|kw)
  87       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  88         targets=($HOME_DOMAIN)
  89       fi
  90       ;;
  91     tp)
  92       targets=(frodo)
  93       if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  94         if timeout -s 9 10 ssh x2 :; then
  95           targets+=(x2)
  96         fi
  97       fi
  98       ;;
  99     frodo)
 100       targets=()
 101       ;;
 102     *)
 103       echo "$0: error: no default targets for this host, use -t"
 104       exit 1
 105       ;;
 106   esac
 107 fi
 108
 109 echo "targets: ${targets[*]}"
 110
 111
 112
 113 # set default mountpoints
 114 case $HOSTNAME in
 115   frodo)
 116     prospective_mps=(/i)
 117     ;;
 118   *)
 119     prospective_mps=(/a /q)
 120     if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 121       prospective_mps+=(/o)
 122     fi
 123     ;;
 124 esac
 125 case ${targets[0]} in
 126   kw|kww)
 127     prospective_mps=(/a)
 128     ;;
 129 esac
 130
 131 for mp in ${prospective_mps[@]}; do # default mountpoints to sync
 132   if [[ -e /nocow/btrfs-stale/$mp ]]; then
 133     echo "$0: warning: $mp stale, not adding to default mountpoints"
 134     continue
 135   fi
 136   if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
 137     mountpoints+=($mp)
 138   fi
 139 done
 140
 141 echo "mountpoints: ${mountpoints[*]}"
 142
 143 ##### end command line parsing ########
 144
 145 rsync-dirs() {
 146   local host=$1
 147   local path=$2
 148   m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 149 }
 150
 151 vol-conf() {
 152   cat >>/etc/btrbk.conf <<EOF
 153 volume $vol
 154 EOF
 155 }
 156 sub-conf() {
 157   cat >>/etc/btrbk.conf <<EOF
 158 subvolume $sub
 159 EOF
 160 }
 161 tg-conf() {
 162   cat >>/etc/btrbk.conf <<EOF
 163 target send-receive ssh://$tg$vol/btrbk
 164 EOF
 165 }
 166 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
 167
 168
 169 if ! which btrbk &>/dev/null; then
 170   echo "$0: error: no btrbk binary found"
 171   exit 1
 172 fi
 173 # if our mountpoints are from stale snapshots,
 174 # it doesn't make sense to do a backup.
 175 check-subvol-stale ${mountpoints[@]} || exit 1
 176
 177
 178 cat >/etc/btrbk.conf <<EOF
 179 ssh_identity /root/.ssh/home
 180 # Just a guess that local7 is a good facility to pick.
 181 # It's a bit odd that the transaction log has to be logged to
 182 # a file or syslog, while other output is sent to std out.
 183 # The man does not mention a way for them to be together, but
 184 # I dunno if setting a log level like warn might also output
 185 # transaction info.
 186 transaction_syslog local7
 187
 188 # 20%ish speedup[]
 189 stream_buffer 512m
 190
 191 # so we only run one at a time
 192 lockfile                   /var/lock/btrbk.lock
 193
 194 # default format of short does not accomidate hourly preservation setting
 195 timestamp_format long-iso
 196
 197 # only make a snapshot if things have changed
 198 snapshot_create onchange
 199 # I could make this different from target_preserve,
 200 # if one disk had less space.
 201 # for now, keeping them equal.
 202 snapshot_preserve 36h 14d 8w 24m
 203 snapshot_preserve_min 4h
 204 snapshot_dir btrbk
 205
 206 # so, total backups = ~89
 207 target_preserve 36h 14d 8w 24m
 208 target_preserve_min 4h
 209
 210 # if something fails and it's not obvious, try doing
 211 # btrbk -l debug -v dryrun
 212
 213 rate_limit $rate_limit
 214 EOF
 215
 216
 217
 218 for tg in ${targets[@]}; do
 219   # for an initial run, btrbk requires the dir to exist.
 220   ssh root@$tg mkdir -p /mnt/root/btrbk
 221 done
 222
 223
 224
 225 for m in ${mountpoints[@]}; do
 226   # for /i, some special cases. there is just one static target and direction.
 227   if [[ $m == /i ]]; then
 228     vol=/mnt/iroot
 229     vol-conf
 230     sub=i
 231     sub-conf
 232     tg=frodo
 233     vol=/mnt/root
 234     tg-conf
 235   else
 236     vol=/mnt/root
 237     vol-conf
 238     sub=${m##*/}
 239     sub-conf
 240     for tg in ${targets[@]}; do
 241       tg-conf
 242     done
 243   fi
 244 done
 245
 246
 247 # todo: umount first to ensure we don't have any errors
 248 # todo: do some kill fuser stuff to make umount more reliable
 249
 250
 251 if $conf_only; then
 252   exit
 253 fi
 254
 255
 256
 257 if $dry_run; then
 258   m btrbk -v -n $cmd_arg
 259 elif [[ $cmd_arg == archive ]]; then
 260     for tg in ${targets[@]}; do
 261       m btrbk $verbose_arg $progress_arg $cmd_arg $vol ssh://$tg$vol
 262     done
 263 else
 264   # -q and just using the syslog option seemed nice,
 265   # but it doesn't show when a send has a parent and when it doesn't.
 266   m btrbk $verbose_arg $progress_arg $cmd_arg
 267 fi
 268
 269 # if we have it, sync to systems which don't
 270 if mountpoint $rsync_mountpoint >/dev/null; then
 271   for tg in ${targets[@]}; do
 272     case $tg in
 273       tp|li|lk)
 274         for x in /p/c/machine_specific/*.hosts; do
 275           if grep -qxF $tg $x; then
 276             dir=${x%.hosts}
 277             rsync-dirs $tg $dir
 278           fi
 279         done
 280         ;;
 281     esac
 282   done
 283 fi
 284
 285 if ! $dry_run; then
 286   m $script_dir/mount-latest-remote ${targets[@]}
 287 fi
 288
 289
 290 # todo: move variable data we don't care about backing up
 291 # to /nocow and symlink it.
 292
 293
 294 # background on btrbk timezones. with short/long, timestamps use local time.
 295 # for long, if your local time moves backwards, by moving timezones or
 296 # for an hour when daylight savings changes it, you will temporarily get
 297 # a more aggressive retention policy for the overlapping period, and
 298 # vice versa for the opposite timezone move. The alternative is using
 299 # long-iso, which puts timezone info into the timestamp, which means
 300 # that instead of shifting time, you shift the start of day/week/month
 301 # which is used for retention to your new local time, which means for
 302 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 303 # retention will be 8 hours more aggressive since midnight is at a new
 304 # time, unless you fake the timzeone using the TZ env variable.
 305 # However, in the short term, there will be no inconsistencies.
 306 # I don't see any problem with shifting when the day starts for
 307 # retention, so I'm using long-iso.
 308
 309 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z