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