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 set -eE -o pipefail
  17 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  18
  19 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
  20
  21 usage() {
  22     echo "top of script file:"
  23     sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  24     exit $1
  25 }
  26
  27 script_dir=$(dirname $(readlink -f "$BASH_SOURCE"))
  28
  29 # note q is owned by root:1000
  30 # note p/m is owned 1000:1000 and chmod 700
  31
  32
  33 targets=()
  34 mountpoints=()
  35
  36 rsync_mountpoint=/q
  37
  38 conf_only=false
  39 dry_run=false # mostly for testing
  40 resume_arg=
  41 rate_limit=no
  42 verbose=false
  43
  44 default_args_file=/etc/btrbk-run.conf
  45 if [[ -s $default_args_file ]]; then
  46     set -- $(< $default_args_file) "$@"
  47 fi
  48
  49 temp=$(getopt -l help cl:m:nprt:vh "$@") || usage 1
  50 eval set -- "$temp"
  51 while true; do
  52     case $1 in
  53         -c) conf_only=true; shift ;;
  54         -l) rate_limit=$2; shift 2 ;;
  55         -m) IFS=, mountpoints=($2); unset IFS; shift 2 ;;
  56         -n) dry_run=true; dry_run_arg=-n; shift ;;
  57         -p) progress_arg="--progress"; shift ;;
  58         # btrbk arg: Resume only. Skips snapshot creation.
  59         -r) resume_arg=-r; shift ;;
  60         -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  61         -v) verbose=true; verbose_arg=-v; shift ;;
  62         -h|--help) usage ;;
  63         --) shift; break ;;
  64         *) echo "$0: Internal error!" ; exit 1 ;;
  65     esac
  66 done
  67
  68 if [[ -s $default_args_file ]]; then
  69     echo "$0: warning: default btrbk-run options set in $default_args_file (sleeping 5 seconds):"
  70     cat $default_args_file
  71     sleep 5
  72 fi
  73
  74 echo -e "$0: options: conf_only=$conf_only\ndry_run=$dry_run\nresume_arg=$resume_arg\nrate_limit=$rate_limit\nverbose=$verbose"
  75
  76 # set default targets
  77 if ! (( ${#targets[@]} )); then
  78     case $HOSTNAME in
  79         x2)
  80             if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  81                 targets=($HOME_DOMAIN)
  82             fi
  83             ;;
  84         treetowl)
  85             targets=(frodo)
  86             if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
  87                 if timeout -s 9 10 ssh x2 :; then
  88                     targets+=(x2)
  89                 fi
  90             fi
  91             ;;
  92         *)
  93             echo "$0: error: no default targets for this host, use -t"
  94             exit 1
  95             ;;
  96     esac
  97 fi
  98
  99 echo "targets: ${targets[*]}"
 100
 101
 102
 103 if (( ${#mountpoints[@]} )); then
 104     for mp in ${mountpoints[@]}; do
 105         if [[ -e /nocow/btrfs-stale/$mp ]]; then
 106             echo "$0: warning: $mp stale. Sleeping for 3 seconds in case you want to cancel."
 107             sleep 3
 108         fi
 109     done
 110 else # set default mountpoints
 111     prospective_mps=(/a /q)
 112     if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
 113         prospective_mps+=(/o)
 114     fi
 115     for tg in ${targets[@]}; do
 116         if [[ $tg == frodo && $HOSTNAME == treetowl ]]; then
 117             prospective_mps+=(/i)
 118         fi
 119     done
 120     for mp in ${prospective_mps[@]}; do # default mountpoints to sync
 121         if [[ -e /nocow/btrfs-stale/$mp ]]; then
 122             echo "$0: warning: $mp stale, not adding to default mountpoints"
 123             continue
 124         fi
 125         if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
 126             mountpoints+=($mp)
 127         fi
 128     done
 129 fi
 130
 131 echo "mountpoints: ${mountpoints[*]}"
 132
 133 ##### end command line parsing ########
 134
 135 rsync-dirs() {
 136     local host=$1
 137     local path=$2
 138     m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
 139 }
 140
 141 vol-conf() {
 142     cat >>/etc/btrbk.conf <<EOF
 143 volume $vol
 144 EOF
 145 }
 146 sub-conf() {
 147     cat >>/etc/btrbk.conf <<EOF
 148 subvolume $sub
 149 EOF
 150 }
 151 tg-conf() {
 152     cat >>/etc/btrbk.conf <<EOF
 153 target send-receive ssh://$tg$vol/btrbk
 154 EOF
 155 }
 156 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
 157
 158
 159 if ! which btrbk &>/dev/null; then
 160     echo "$0: error: no btrbk binary found"
 161 fi
 162
 163 cat >/etc/btrbk.conf <<EOF
 164 ssh_identity /root/.ssh/id_rsa
 165 # Just a guess that local7 is a good facility to pick.
 166 # It's a bit odd that the transaction log has to be logged to
 167 # a file or syslog, while other output is sent to std out.
 168 # The man does not mention a way for them to be together, but
 169 # I dunno if setting a log level like warn might also output
 170 # transaction info.
 171 transaction_syslog local7
 172
 173 # so we only run one at a time
 174 lockfile                   /var/lock/btrbk.lock
 175
 176 # default format of short does not accomidate hourly preservation setting
 177 timestamp_format long-iso
 178
 179 # only make a snapshot if things have changed
 180 snapshot_create onchange
 181 # I could make this different from target_preserve,
 182 # if one disk had less space.
 183 # for now, keeping them equal.
 184 snapshot_preserve 36h 14d 8w 24m
 185 snapshot_preserve_min 4h
 186 snapshot_dir btrbk
 187
 188 # so, total backups = ~89
 189 target_preserve 36h 14d 8w 24m
 190 target_preserve_min 4h
 191
 192 # if something fails and it's not obvious, try doing
 193 # btrbk -l debug -v dryrun
 194
 195 rate_limit $rate_limit
 196 EOF
 197
 198
 199 # if our mountpoints are from stale snapshots,
 200 # it doesn't make sense to do a backup.
 201 check-subvol-stale ${mountpoints[@]} || exit 1
 202
 203 for tg in ${targets[@]}; do
 204     # for an initial run, btrbk requires the dir to exist
 205     ssh root@$tg mkdir -p /mnt/root/btrbk
 206 done
 207
 208
 209 for m in ${mountpoints[@]}; do
 210     # for /i, some special cases. there is just one static target and direction.
 211     if [[ $m == /i ]]; then
 212         vol=/mnt/iroot
 213         vol-conf
 214         sub=i
 215         sub-conf
 216         tg=frodo
 217         vol=/mnt/root
 218         tg-conf
 219     else
 220         vol=/mnt/root
 221         vol-conf
 222         sub=${m##*/}
 223         sub-conf
 224         for tg in ${targets[@]}; do
 225             tg-conf
 226         done
 227     fi
 228 done
 229
 230
 231 # todo: umount first to ensure we don't have any errors
 232 # todo: do some kill fuser stuff to make umount more reliable
 233
 234
 235 if $conf_only; then
 236     exit
 237 fi
 238
 239 if $dry_run; then
 240     m btrbk -v -n $resume_arg run
 241 else
 242     # -q and just using the syslog option seemed nice,
 243     # but it doesn't show when a send has a parent and when it doesn't.
 244     m btrbk $verbose_arg $progress_arg $resume_arg run
 245 fi
 246
 247 # if we have it, sync to systems which don't
 248 if mountpoint $rsync_mountpoint >/dev/null; then
 249     for tg in ${targets[@]}; do
 250         case $tg in
 251             tp|li|lk)
 252                 for x in /p/c/machine_specific/*.hosts; do
 253                     if grep -qxF $tg $x; then
 254                         dir=${x%.hosts}
 255                         rsync-dirs $tg $dir
 256                     fi
 257                 done
 258                 ;;
 259         esac
 260     done
 261 fi
 262
 263 if ! $dry_run; then
 264     m $script_dir/mount-latest-remote ${targets[@]}
 265 fi
 266
 267
 268 # todo: move variable data we don't care about backing up
 269 # to /nocow and symlink it.
 270
 271
 272 # background on btrbk timezones. with short/long, timestamps use local time.
 273 # for long, if your local time moves backwards, by moving timezones or
 274 # for an hour when daylight savings changes it, you will temporarily get
 275 # a more aggressive retention policy for the overlapping period, and
 276 # vice versa for the opposite timezone move. The alternative is using
 277 # long-iso, which puts timezone info into the timestamp, which means
 278 # that instead of shifting time, you shift the start of day/week/month
 279 # which is used for retention to your new local time, which means for
 280 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 281 # retention will be 8 hours more aggressive since midnight is at a new
 282 # time, unless you fake the timzeone using the TZ env variable.
 283 # However, in the short term, there will be no inconsistencies.
 284 # I don't see any problem with shifting when the day starts for
 285 # retention, so I'm using long-iso.
 286
 287 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z