+### end options parsing
+
+# TODO: i wonder if there should be an option to send to the default
+# targets, plus any given on the command line.
+
+# set default targets
+if [[ ! -v targets && ! $source ]]; then
+ if [[ $HOSTNAME != "$MAIL_HOST" ]] && $cron ; then
+ echo "MAIL_HOST=$MAIL_HOST, nothing to do"
+ exit 0
+ fi
+
+ at_work=false
+
+ case $HOSTNAME in
+ kw)
+ at_work=true
+ ;;&
+ x2|x3)
+ if ping -q -c1 -w1 hal.office.fsf.org \
+ && ip n show 192.168.0.26 | grep . &>/dev/null; then
+ at_work=true
+ fi
+ ;;&
+ kw|x2|x3)
+ if $at_work && ping -q -c1 -w1 iank.vpn.office.fsf.org &>/dev/null; then
+ home=iank.vpn.office.fsf.org
+ else
+ home=b8.nz
+ fi
+ ;;&
+ kw)
+ targets=($home x2)
+ ;;
+ x2|x3)
+ targets=($home kw)
+ ;;
+ tp)
+ # kd disabled temporarily while its hot and i plan to work on it.
+ #targets=(frodo kd)
+ targets=(frodo x3.b8.nz)
+ # might not be connected to the vpn
+ if timeout -s 9 10 ssh kw :; then
+ targets+=(kw)
+ fi
+ ;;
+ kd)
+ targets=(frodo tp)
+ # might not be connected to the vpn
+ if timeout -s 9 10 ssh kw :; then
+ targets+=(kw)
+ fi
+ ;;
+ *)
+ die "error: no default targets for this host, use -t"
+ ;;
+ esac
+fi
+
+if [[ -v targets ]]; then
+ echo "targets: ${targets[*]}"
+fi
+
+if [[ $source ]]; then
+ echo "source: $source"
+fi
+
+
+if [[ $mountpoints ]]; then
+ for mp in ${mountpoints[@]}; do # default mountpoints to sync
+ if [[ -e /nocow/btrfs-stale/$mp ]]; then
+ die "error: $mp is stale, mount-latest-subvol first"
+ fi
+ done
+else
+ # set default mountpoints
+ case $HOSTNAME in
+ # no remote backups atm. note, if we do enable this, configuration below will need some changes.
+ # frodo)
+ # prospective_mps=(/i)
+ # ;;
+ *)
+ prospective_mps=(/a /q)
+ if [[ $source ]]; then
+ source_state="$(ssh $source cat /a/bin/bash_unpublished/source-state)"
+ eval "$source_state"
+ source_host="$(ssh $source cat /etc/hostname)"
+ if [[ $source_host == "$MAIL_HOST" ]]; then
+ prospective_mps+=(/o)
+ fi
+ else
+ if [[ $HOSTNAME == "$MAIL_HOST" ]]; then
+ prospective_mps+=(/o)
+ fi
+ fi
+ ;;
+ esac
+ for mp in ${prospective_mps[@]}; do # default mountpoints to sync
+ if [[ -e /nocow/btrfs-stale/$mp ]]; then
+ e "warning: $mp stale, not adding to default mountpoints"
+ continue
+ fi
+ if awk '{print $2}' /etc/fstab | grep -xF $mp &>/dev/null; then
+ mountpoints+=($mp)
+ fi
+ done
+fi
+
+echo "mountpoints: ${mountpoints[*]}"
+
+##### end command line parsing ########
+
+if [[ $source ]]; then
+ if [[ $(ssh $source systemctl is-active btrbk.service) != inactive ]]; then
+ echo "$0: error: cron btrbk is running on source. exiting out of caution"
+ exit 1
+ fi
+fi
+
+# pull_reexec stops us from getting into an infinite loop if there is some
+# kind of weird problem
+pulla=false
+for m in "${mountpoints[@]}"; do
+ if [[ $m == /a ]]; then
+ pulla=true
+ break
+ fi
+done
+if ! $pull_reexec && [[ $source ]] && $pulla ; then
+ tmpf=$(mktemp)
+ scp $source:/a/bin/distro-setup/btrbk-run $tmpf
+ if ! diff -q $tmpf $BASH_SOURCE; then
+ e "found newer version on host $source. reexecing"
+ install -T $tmpf /usr/local/bin/btrbk-run
+ m /usr/local/bin/btrbk-run --pull-reexec "${orig_args[@]}"
+ exit
+ fi
+fi
+
+
+
+
+
+if ! which btrbk &>/dev/null; then
+ die "error: no btrbk binary found"
+fi
+# if our mountpoints are from stale snapshots,
+# it doesn't make sense to do a backup.
+check-subvol-stale ${mountpoints[@]} || die "found stale mountpoints in ${mountpoints[*]}"
+
+# for an initial run, btrbk requires the dir to exist.
+mkdir -p /mnt/root/btrbk
+local_zone=$(date +%z)
+
+if [[ $source ]]; then
+ if ! zone=$(ssh root@$source date +%z); then
+ die failed to ssh to root@$source
+ fi
+ if [[ $zone != $local_zone ]]; then
+ die "error: dont confuse yourself with multiple time zones. $h has different timezone than localhost"
+ fi
+
+else