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
  35 temp=$(getopt -l help hcnprt: "$@") || usage 1
  36 eval set -- "$temp"
  37 while true; do
  38     case $1 in
  39         -c) conf_only=true; shift ;;
  40         -n) dry_run=true; dry_run_arg=-n; shift ;;
  41         -p) progress_arg="--progress"; shift ;;
  42         # btrbk arg: Resume only. Skips snapshot creation.
  43         -r) resume_arg=-r; shift ;;
  44         -t) IFS=, targets=($2); unset IFS; shift 2 ;;
  45         -h|--help) usage ;;
  46         --) shift; break ;;
  47         *) echo "$0: Internal error!" ; exit 1 ;;
  48     esac
  49 done
  50 read primary <<<"$@"
  51
  52 ##### end command line parsing ########
  53
  54 rsync-dirs() {
  55     local host=$1
  56     local path=$2
  57     m rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
  58 }
  59
  60 vol-conf() {
  61     cat >>/etc/btrbk.conf <<EOF
  62 volume $vol
  63 EOF
  64 }
  65 sub-conf() {
  66     cat >>/etc/btrbk.conf <<EOF
  67 subvolume $sub
  68 EOF
  69 }
  70 tg-conf() {
  71     cat >>/etc/btrbk.conf <<EOF
  72 target send-receive ssh://$tg$vol/btrbk
  73 EOF
  74 }
  75 m() { printf "%s: %s\n" "${0##*/}" "$*";  "$@"; }
  76
  77
  78 if ! which btrbk &>/dev/null; then
  79     echo "$0: error: no btrbk binary found"
  80 fi
  81
  82 cat >/etc/btrbk.conf <<'EOF'
  83 ssh_identity /root/.ssh/id_rsa
  84 # Just a guess that local7 is a good facility to pick.
  85 # It's a bit odd that the transaction log has to be logged to
  86 # a file or syslog, while other output is sent to std out.
  87 # The man does not mention a way for them to be together, but
  88 # I dunno if setting a log level like warn might also output
  89 # transaction info.
  90 transaction_syslog local7
  91
  92 # so we only run one at a time
  93 lockfile                   /var/lock/btrbk.lock
  94
  95 # default format of short does not accomidate hourly preservation setting
  96 timestamp_format long-iso
  97
  98 # only make a snapshot if things have changed
  99 snapshot_create onchange
 100 # much less snapshots because I have less space on the
 101 # local filesystem.
 102 #snapshot_preserve 2h 2d
 103 # for now, keeping them equal for simplicity sake
 104 snapshot_preserve 48h 14d 8w 24m
 105 snapshot_preserve_min 6h
 106 snapshot_dir btrbk
 107
 108 # so, total backups = ~89
 109 target_preserve 48h 14d 8w 24m
 110 target_preserve_min 6h
 111
 112 # if something fails and it's not obvious, try doing
 113 # btrbk -l debug -v dryrun
 114 EOF
 115
 116 # note q is owned by root:1000
 117 # note p is owned 1000:1000 and chmod 700
 118 mountpoints=(/a)
 119 qmnt=/q
 120 if awk '{print $2}' /etc/fstab | grep -xF $qmnt &>/dev/null; then
 121     mountpoints+=($qmnt)
 122 fi
 123
 124 # if our mountpoints are from stale snapshots,
 125 # it doesn't make sense to do a backup.
 126 check-subvol-stale ${mountpoints[@]} || exit 1
 127
 128 if [[ ! $targets ]]; then
 129     case $HOSTNAME in
 130         tp|x2)
 131             if ! timeout -s 9 10 ssh frodo :; then
 132                 targets=($HOME_DOMAIN)
 133             fi
 134             ;;
 135         treetowl)
 136             targets=(frodo)
 137             if timeout -s 9 10 ssh x2 :; then
 138                 targets+=(x2)
 139             fi
 140             ;;
 141         *)
 142             targets=(frodo)
 143             ;;
 144     esac
 145     echo "targets: ${targets[*]}"
 146 fi
 147
 148
 149 # for i, we just do a 1 way sync from master to backup,
 150 # and manually manage any changes to that.
 151 do_i=false
 152 for tg in ${targets[@]}; do
 153     # for an initial run, btrbk requires the dir to exist
 154     ssh root@$tg mkdir -p /mnt/root/btrbk
 155     if [[ $tg == frodo && $HOSTNAME == treetowl ]]; then
 156         do_i=true
 157     fi
 158 done
 159
 160
 161 vol=/mnt/root
 162 vol-conf
 163 for m in ${mountpoints[@]}; do
 164     sub=${m##*/}
 165     sub-conf
 166     for tg in ${targets[@]}; do
 167         tg-conf
 168     done
 169 done
 170
 171 if $do_i; then
 172     vol=/mnt/iroot
 173     vol-conf
 174     sub=i
 175     sub-conf
 176     tg=frodo
 177     vol=/mnt/root
 178     tg-conf
 179 fi
 180
 181
 182
 183 # todo: umount first to ensure we don't have any errors
 184 # todo: do some kill fuser stuff to make umount more reliable
 185 # todo: run this on a systemd timer on $primary, once per hour,
 186 # and if primary is, change that timer over to primary, and make
 187 # sure we mount the latest
 188
 189
 190
 191 if $conf_only; then
 192     exit
 193 fi
 194
 195 if $dry_run; then
 196     m btrbk -n $resume_arg run
 197 else
 198     # -q and just using the syslog option seemed nice,
 199     # but it doesn't show when a send has a parent and when it doesn't.
 200     m btrbk $progress_arg $resume_arg run
 201 fi
 202
 203 # if we have /p, rsync to targets without /p
 204 if mountpoint /p >/dev/null; then
 205     for tg in ${targets[@]}; do
 206         case $tg in
 207             tp|li|lk)
 208                 for x in /p/c/machine_specific/*.hosts; do
 209                     if grep -qxF $tg $x; then
 210                         dir=${x%.hosts}
 211                         rsync-dirs $tg $dir
 212                     fi
 213                 done
 214                 ;;
 215         esac
 216     done
 217 fi
 218
 219 if ! $dry_run; then
 220     m $script_dir/mount-latest-remote ${targets[@]}
 221 fi
 222
 223
 224 # todo: move variable data we don't care about backing up
 225 # to /nocow and symlink it.
 226
 227
 228 # background on btrbk timezones. with short/long, timestamps use local time.
 229 # for long, if your local time moves backwards, by moving timezones or
 230 # for an hour when daylight savings changes it, you will temporarily get
 231 # a more aggressive retention policy for the overlapping period, and
 232 # vice versa for the opposite timezone move. The alternative is using
 233 # long-iso, which puts timezone info into the timestamp, which means
 234 # that instead of shifting time, you shift the start of day/week/month
 235 # which is used for retention to your new local time, which means for
 236 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 237 # retention will be 8 hours more aggressive since midnight is at a new
 238 # time, unless you fake the timzeone using the TZ env variable.
 239 # However, in the short term, there will be no inconsistencies.
 240 # I don't see any problem with shifting when the day starts for
 241 # retention, so I'm using long-iso.
 242
 243 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z