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 # todo: finish figuring out fai / distro-setup
  29 # initial fstab / subvol setup.
  30
  31 conf_only=false
  32 dry_run=false # mostly for testing
  33 resume_arg=
  34 do_i=true
  35
  36 temp=$(getopt -l help hcinprt: "$@") || usage 1
  37 eval set -- "$temp"
  38 while true; do
  39     case $1 in
  40         -c) conf_only=true; shift ;;
  41         -i) do_i=false; shift ;;
  42         -n) dry_run=true; dry_run_arg=-n; shift ;;
  43         -p) progress_arg="--progress"; shift ;;
  44         # btrbk arg: Resume only. Skips snapshot creation.
  45         -r) resume_arg=-r; shift ;;
  46         -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  47         -h|--help) usage ;;
  48         --) shift; break ;;
  49         *) echo "$0: Internal error!" ; exit 1 ;;
  50     esac
  51 done
  52 read primary <<<"$@"
  53
  54 ##### end command line parsing ########
  55
  56 rsync-dirs() {
  57     local host=$1
  58     local path=$2
  59     m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
  60 }
  61
  62 vol-conf() {
  63     cat >>/etc/btrbk.conf <<EOF
  64 volume $vol
  65 EOF
  66 }
  67 sub-conf() {
  68     cat >>/etc/btrbk.conf <<EOF
  69 subvolume $sub
  70 EOF
  71 }
  72 tg-conf() {
  73     cat >>/etc/btrbk.conf <<EOF
  74 target send-receive ssh://$tg$vol/btrbk
  75 EOF
  76 }
  77 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
  78
  79
  80 if ! which btrbk &>/dev/null; then
  81     echo "$0: error: no btrbk binary found"
  82 fi
  83
  84 cat >/etc/btrbk.conf <<'EOF'
  85 ssh_identity /root/.ssh/id_rsa
  86 # Just a guess that local7 is a good facility to pick.
  87 # It's a bit odd that the transaction log has to be logged to
  88 # a file or syslog, while other output is sent to std out.
  89 # The man does not mention a way for them to be together, but
  90 # I dunno if setting a log level like warn might also output
  91 # transaction info.
  92 transaction_syslog local7
  93
  94 # so we only run one at a time
  95 lockfile                   /var/lock/btrbk.lock
  96
  97 # default format of short does not accomidate hourly preservation setting
  98 timestamp_format long-iso
  99
 100 # only make a snapshot if things have changed
 101 snapshot_create onchange
 102 # I could make this different from target_preserve,
 103 # if one disk had less space.
 104 # for now, keeping them equal.
 105 snapshot_preserve 36h 14d 8w 24m
 106 snapshot_preserve_min 4h
 107 snapshot_dir btrbk
 108
 109 # so, total backups = ~89
 110 target_preserve 36h 14d 8w 24m
 111 target_preserve_min 4h
 112
 113 # if something fails and it's not obvious, try doing
 114 # btrbk -l debug -v dryrun
 115 EOF
 116
 117 # note q is owned by root:1000
 118 # note p is owned 1000:1000 and chmod 700
 119 mountpoints=(/a)
 120 qmnt=/q
 121 if awk '{print $2}' /etc/fstab | grep -xF $qmnt &>/dev/null; then
 122     mountpoints+=($qmnt)
 123 fi
 124
 125 # if our mountpoints are from stale snapshots,
 126 # it doesn't make sense to do a backup.
 127 check-subvol-stale ${mountpoints[@]} || exit 1
 128
 129 if [[ ! $targets ]]; then
 130     case $HOSTNAME in
 131         tp|x2)
 132             if ! timeout -s 9 10 ssh frodo :; then
 133                 targets=($HOME_DOMAIN)
 134             fi
 135             ;;
 136         treetowl)
 137             targets=(frodo)
 138             if timeout -s 9 10 ssh x2 :; then
 139                 targets+=(x2)
 140             fi
 141             ;;
 142         *)
 143             targets=(frodo)
 144             ;;
 145     esac
 146     echo "targets: ${targets[*]}"
 147 fi
 148
 149
 150 # for i, we just do a 1 way sync from master to backup,
 151 # and manually manage any changes to that.
 152 i_possible=false
 153 for tg in ${targets[@]}; do
 154     # for an initial run, btrbk requires the dir to exist
 155     ssh root@$tg mkdir -p /mnt/root/btrbk
 156     if [[ $tg == frodo && $HOSTNAME == treetowl ]]; then
 157         i_possible=true
 158     fi
 159 done
 160 if ! $i_possible; then
 161     do_i=false
 162 fi
 163
 164
 165 vol=/mnt/root
 166 vol-conf
 167 for m in ${mountpoints[@]}; do
 168     sub=${m##*/}
 169     sub-conf
 170     for tg in ${targets[@]}; do
 171         tg-conf
 172     done
 173 done
 174
 175 if $do_i; then
 176     vol=/mnt/iroot
 177     vol-conf
 178     sub=i
 179     sub-conf
 180     tg=frodo
 181     vol=/mnt/root
 182     tg-conf
 183 fi
 184
 185
 186
 187 # todo: umount first to ensure we don't have any errors
 188 # todo: do some kill fuser stuff to make umount more reliable
 189 # todo: run this on a systemd timer on $primary, once per hour,
 190 # and if primary is, change that timer over to primary, and make
 191 # sure we mount the latest
 192
 193
 194
 195 if $conf_only; then
 196     exit
 197 fi
 198
 199 if $dry_run; then
 200     m btrbk -n $resume_arg run
 201 else
 202     # -q and just using the syslog option seemed nice,
 203     # but it doesn't show when a send has a parent and when it doesn't.
 204     m btrbk $progress_arg $resume_arg run
 205 fi
 206
 207 # if we have /p, rsync to targets without /p
 208 if mountpoint /p >/dev/null; then
 209     for tg in ${targets[@]}; do
 210         case $tg in
 211             tp|li|lk)
 212                 for x in /p/c/machine_specific/*.hosts; do
 213                     if grep -qxF $tg $x; then
 214                         dir=${x%.hosts}
 215                         rsync-dirs $tg $dir
 216                     fi
 217                 done
 218                 ;;
 219         esac
 220     done
 221 fi
 222
 223 if ! $dry_run; then
 224     m $script_dir/mount-latest-remote ${targets[@]}
 225 fi
 226
 227
 228 # todo: move variable data we don't care about backing up
 229 # to /nocow and symlink it.
 230
 231
 232 # background on btrbk timezones. with short/long, timestamps use local time.
 233 # for long, if your local time moves backwards, by moving timezones or
 234 # for an hour when daylight savings changes it, you will temporarily get
 235 # a more aggressive retention policy for the overlapping period, and
 236 # vice versa for the opposite timezone move. The alternative is using
 237 # long-iso, which puts timezone info into the timestamp, which means
 238 # that instead of shifting time, you shift the start of day/week/month
 239 # which is used for retention to your new local time, which means for
 240 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 241 # retention will be 8 hours more aggressive since midnight is at a new
 242 # time, unless you fake the timzeone using the TZ env variable.
 243 # However, in the short term, there will be no inconsistencies.
 244 # I don't see any problem with shifting when the day starts for
 245 # retention, so I'm using long-iso.
 246
 247 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z