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: remove old leaf subvols, like keep up to 1 month or something.
  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 resume_arg=
  43 rate_limit=no
  44 verbose=false
  45
  46 default_args_file=/etc/btrbk-run.conf
  47 if [[ -s $default_args_file ]]; then
  48     set -- $(< $default_args_file) "$@"
  49 fi
  50
  51 temp=$(getopt -l help cl:m:nprt:vh "$@") || usage 1
  52 eval set -- "$temp"
  53 while true; do
  54     case $1 in
  55         # only creates the config file, does not run btrbk
  56         -c) conf_only=true; shift ;;
  57         -l) rate_limit=$2; shift 2 ;;
  58         -m) IFS=, mountpoints=($2); unset IFS; shift 2 ;;
  59         -n) dry_run=true; dry_run_arg=-n; shift ;;
  60         -p) progress_arg="--progress"; shift ;;
  61         # btrbk arg: Resume only. Skips snapshot creation.
  62         -r) resume_arg=-r; shift ;;
  63         # empty is valid for just doing local snapshot. we have default hosts
  64         # we will populate
  65         -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  66         -v) verbose=true; verbose_arg=-v; shift ;;
  67         -h|--help) usage ;;
  68         --) shift; break ;;
  69         *) echo "$0: Internal error!" ; exit 1 ;;
  70     esac
  71 done
  72
  73 if [[ -s $default_args_file ]]; then
  74     echo "$0: warning: default btrbk-run options set in $default_args_file (sleeping 5 seconds):"
  75     cat $default_args_file
  76     sleep 5
  77 fi
  78
  79 echo -e "$0: options: conf_only=$conf_only\ndry_run=$dry_run\nresume_arg=$resume_arg\nrate_limit=$rate_limit\nverbose=$verbose"
  80
  81 # set default targets
  82 if [[ ! -v targets ]]; then
  83     case $HOSTNAME in
  84         x2|fz)
  85             if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  86                 targets=($HOME_DOMAIN)
  87             fi
  88             ;;
  89         tp)
  90             targets=(frodo)
  91             if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  92                 if timeout -s 9 10 ssh x2 :; then
  93                     targets+=(x2)
  94                 fi
  95             fi
  96             ;;
  97         frodo)
  98             targets=()
  99             ;;
 100         *)
 101             echo "$0: error: no default targets for this host, use -t"
 102             exit 1
 103             ;;
 104     esac
 105 fi
 106
 107 echo "targets: ${targets[*]}"
 108
 109
 110
 111 if (( ${#mountpoints[@]} )); then
 112     for mp in ${mountpoints[@]}; do
 113         if [[ -e /nocow/btrfs-stale/$mp ]]; then
 114             echo "$0: warning: $mp stale. Sleeping for 3 seconds in case you want to cancel."
 115             sleep 3
 116         fi
 117     done
 118 else # set default mountpoints
 119     case $HOSTNAME in
 120         frodo)
 121             prospective_mps=(/i)
 122             ;;
 123         *)
 124             prospective_mps=(/a /q)
 125             if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 126                 prospective_mps+=(/o)
 127             fi
 128             ;;
 129     esac
 130     case ${targets[0]} in
 131         kw|kww)
 132             prospective_mps=(/a)
 133             ;;
 134     esac
 135
 136     for mp in ${prospective_mps[@]}; do # default mountpoints to sync
 137         if [[ -e /nocow/btrfs-stale/$mp ]]; then
 138             echo "$0: warning: $mp stale, not adding to default mountpoints"
 139             continue
 140         fi
 141         if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
 142             mountpoints+=($mp)
 143         fi
 144     done
 145 fi
 146
 147 echo "mountpoints: ${mountpoints[*]}"
 148
 149 ##### end command line parsing ########
 150
 151 rsync-dirs() {
 152     local host=$1
 153     local path=$2
 154     m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 155 }
 156
 157 vol-conf() {
 158     cat >>/etc/btrbk.conf <<EOF
 159 volume $vol
 160 EOF
 161 }
 162 sub-conf() {
 163     cat >>/etc/btrbk.conf <<EOF
 164 subvolume $sub
 165 EOF
 166 }
 167 tg-conf() {
 168     cat >>/etc/btrbk.conf <<EOF
 169 target send-receive ssh://$tg$vol/btrbk
 170 EOF
 171 }
 172 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
 173
 174
 175 if ! which btrbk &>/dev/null; then
 176     echo "$0: error: no btrbk binary found"
 177 fi
 178
 179 cat >/etc/btrbk.conf <<EOF
 180 ssh_identity /root/.ssh/home
 181 # Just a guess that local7 is a good facility to pick.
 182 # It's a bit odd that the transaction log has to be logged to
 183 # a file or syslog, while other output is sent to std out.
 184 # The man does not mention a way for them to be together, but
 185 # I dunno if setting a log level like warn might also output
 186 # transaction info.
 187 transaction_syslog local7
 188
 189 # so we only run one at a time
 190 lockfile                   /var/lock/btrbk.lock
 191
 192 # default format of short does not accomidate hourly preservation setting
 193 timestamp_format long-iso
 194
 195 # only make a snapshot if things have changed
 196 snapshot_create onchange
 197 # I could make this different from target_preserve,
 198 # if one disk had less space.
 199 # for now, keeping them equal.
 200 snapshot_preserve 36h 14d 8w 24m
 201 snapshot_preserve_min 4h
 202 snapshot_dir btrbk
 203
 204 # so, total backups = ~89
 205 target_preserve 36h 14d 8w 24m
 206 target_preserve_min 4h
 207
 208 # if something fails and it's not obvious, try doing
 209 # btrbk -l debug -v dryrun
 210
 211 rate_limit $rate_limit
 212 EOF
 213
 214
 215 # if our mountpoints are from stale snapshots,
 216 # it doesn't make sense to do a backup.
 217 check-subvol-stale ${mountpoints[@]} || exit 1
 218
 219 for tg in ${targets[@]}; do
 220     # for an initial run, btrbk requires the dir to exist
 221     ssh root@$tg mkdir -p /mnt/root/btrbk
 222 done
 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 if $dry_run; then
 256     m btrbk -v -n $resume_arg run
 257 else
 258     # -q and just using the syslog option seemed nice,
 259     # but it doesn't show when a send has a parent and when it doesn't.
 260     m btrbk $verbose_arg $progress_arg $resume_arg run
 261 fi
 262
 263 # if we have it, sync to systems which don't
 264 if mountpoint $rsync_mountpoint >/dev/null; then
 265     for tg in ${targets[@]}; do
 266         case $tg in
 267             tp|li|lk)
 268                 for x in /p/c/machine_specific/*.hosts; do
 269                     if grep -qxF $tg $x; then
 270                         dir=${x%.hosts}
 271                         rsync-dirs $tg $dir
 272                     fi
 273                 done
 274                 ;;
 275         esac
 276     done
 277 fi
 278
 279 if ! $dry_run; then
 280     m $script_dir/mount-latest-remote ${targets[@]}
 281 fi
 282
 283
 284 # todo: move variable data we don't care about backing up
 285 # to /nocow and symlink it.
 286
 287
 288 # background on btrbk timezones. with short/long, timestamps use local time.
 289 # for long, if your local time moves backwards, by moving timezones or
 290 # for an hour when daylight savings changes it, you will temporarily get
 291 # a more aggressive retention policy for the overlapping period, and
 292 # vice versa for the opposite timezone move. The alternative is using
 293 # long-iso, which puts timezone info into the timestamp, which means
 294 # that instead of shifting time, you shift the start of day/week/month
 295 # which is used for retention to your new local time, which means for
 296 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 297 # retention will be 8 hours more aggressive since midnight is at a new
 298 # time, unless you fake the timzeone using the TZ env variable.
 299 # However, in the short term, there will be no inconsistencies.
 300 # I don't see any problem with shifting when the day starts for
 301 # retention, so I'm using long-iso.
 302
 303 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z