iankelling.org Git - distro-setup/blob - btrbk-run

   1 #!/bin/bash
   2
   3 set -eE -o pipefail
   4 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
   5
   6 [[ $EUID == 0 ]] || exec sudo -E "$BASH_SOURCE" "$@"
   7
   8 usage() {
   9     echo "top of script file:"
  10     sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  11     exit $1
  12 }
  13
  14 script_dir=$(dirname $(readlink "$BASH_SOURCE"))
  15
  16 # todo: finish figuring out fai / distro-setup
  17 # initial fstab / subvol setup.
  18
  19 conf_only=false
  20 dry_run=false # mostly for testing
  21 resume_arg=
  22
  23 temp=$(getopt -l help hcnrt: "$@") || usage 1
  24 eval set -- "$temp"
  25 while true; do
  26     case $1 in
  27         -c) conf_only=true; shift ;;
  28         -n) dry_run=true; dry_run_arg=-n; shift ;;
  29         -r) resume_arg=-r; shift ;;
  30         -t) IFS=, targets=($2); shift 2 ;;
  31         -h|--help) usage ;;
  32         --) shift; break ;;
  33         *) echo "$0: Internal error!" ; exit 1 ;;
  34     esac
  35 done
  36 read primary <<<"$@"
  37
  38 ##### end command line parsing ########
  39
  40 target-section() {
  41     local root=$1
  42     local subvol=$2
  43     mountpoint $root &>/dev/null || return
  44     cat >>/etc/btrbk.conf <<EOF
  45 volume $root
  46 subvolume $subvol
  47 $remote_target
  48
  49 EOF
  50 }
  51
  52 rsync-dirs() {
  53     local host=$1
  54     local path=$2
  55     rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
  56 }
  57
  58
  59 # note q is owned by root:1000
  60 # note p is owned 1000:1000 and chmod 700
  61 mountpoints=(/q)
  62 if awk '{print $2}' /etc/fstab | grep -xF /p &>/dev/null; then
  63     mountpoints+=(/p)
  64 fi
  65
  66 # if our mountpoints are from stale snapshots,
  67 # it doesn't make sense to do a backup.
  68 check-subvol-stale ${mountpoints[@]} || exit 1
  69
  70 if [[ ! $targets ]]; then
  71     case $HOSTNAME in
  72         tp|x2)
  73             if ! timeout -s 9 10 ssh frodo :; then
  74                 targets=($HOME_DOMAIN)
  75             fi
  76             ;;
  77     esac
  78     targets=(frodo)
  79 fi
  80
  81
  82 # todo: make bash shell prompt show something when
  83 # a subvol on current host is not fresh.
  84 # umount first to ensure we don't have any errors
  85 # todo: do some kill fuser stuff to make umount more reliable
  86 # todo: run this on a systemd timer on $primary, once per hour,
  87 # and if primary is, change that timer over to primary, and make
  88 # sure we mount the latest
  89 # todo: setup lock so that if this is already running, we exit out, so
  90 # that manual runs don't interfere with cronjobs.
  91
  92 for tg in ${targets[@]}; do
  93     cat >/etc/btrbk.conf <<'EOF'
  94 ssh_identity /root/.ssh/id_rsa
  95 transaction_syslog daemon
  96
  97 # so we only run one at a time
  98 lockfile                   /var/lock/btrbk.lock
  99
 100 # default format of short does not accomidate hourly preservation setting
 101 timestamp_format long-iso
 102
 103 # only make a snapshot if things have changed
 104 snapshot_create onchange
 105 # much less snapshots because I have less space on the
 106 # local filesystem.
 107 #snapshot_preserve 2h 2d
 108 # for now, keeping them equal for simplicity sake
 109 snapshot_preserve 48h 14d 8w 24m
 110 snapshot_preserve_min 6h
 111 snapshot_dir btrbk
 112
 113 # so, total backups = ~89
 114 target_preserve 48h 14d 8w 24m
 115 target_preserve_min 6h
 116
 117 # if something fails and it's not obvious, try doing
 118 # btrbk -l debug -v dryrun
 119 EOF
 120
 121     remote_target="target send-receive ssh://${tg}/mnt/root/btrbk"
 122
 123     if [[ $tg == frodo && $HOSTNAME == treetowl ]]; then
 124         target-section /mnt/iroot i
 125     fi
 126     for d in ${mountpoints[@]}; do
 127         target-section /mnt/root ${d##*/}
 128     done
 129 done
 130
 131 if $conf_only; then
 132     exit
 133 fi
 134
 135 if $dry_run; then
 136     btrbk -n $resume_arg run
 137 else
 138     btrbk -q $resume_arg run
 139 fi
 140
 141 # if we have /p, rsync to targets without /p
 142 if mountpoint /p >/dev/null; then
 143     for tg in ${targets[@]}; do
 144         case $tg in
 145             tp|li|lk)
 146                 for x in /p/c/machine_specific/*.hosts; do
 147                     if grep -qxF $tg $x; then
 148                         dir=${x%.hosts}
 149                         rsync-dirs $tg $dir
 150                     fi
 151                 done
 152                 ;;
 153         esac
 154     done
 155 fi
 156
 157 if ! $dry_run; then
 158     for tg in ${targets[@]}; do
 159         scp $script_dir/{mount-latest-subvol,check-subvol-stale} \
 160             root@$tg:/usr/local/bin
 161         ssh root@$tg bash <<'EOF'
 162 set -e
 163 chmod +x /usr/local/bin/{mount-latest-subvol,check-subvol-stale}
 164 mount-latest-subvol
 165 EOF
 166     done
 167 fi
 168
 169
 170 # todo: move variable data we don't care about backing up
 171 # to /nocow and symlink it.
 172
 173
 174 # background on btrbk timezones. with short/long, timestamps use local time.
 175 # for long, if your local time moves backwards, by moving timezones or
 176 # for an hour when daylight savings changes it, you will temporarily get
 177 # a more aggressive retention policy for the overlapping period, and
 178 # vice versa for the opposite timezone move. The alternative is using
 179 # long-iso, which puts timezone info into the timestamp, which means
 180 # that instead of shifting time, you shift the start of day/week/month
 181 # which is used for retention to your new local time, which means for
 182 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 183 # retention will be 8 hours more aggressive since midnight is at a new
 184 # time, unless you fake the timzeone using the TZ env variable.
 185 # However, in the short term, there will be no inconsistencies.
 186 # I don't see any problem with shifting when the day starts for
 187 # retention, so I'm using long-iso.
 188
 189 # note to create a long-iso timestamp: date +%Y%m%dT%H%M%S%z