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