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