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