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