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