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

   1 #!/bin/bash -l
   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 conf_only=false
   9 dry_run=false
  10 # mostly for testing
  11 case $1 in
  12     -c) conf_only=true ;;
  13     -n) dry_run=true ;;
  14     ?*) echo "$0: error: unsupported arg"; exit 1 ;;
  15 esac
  16
  17 # background on timezones. with short/long, timestamps use local time.
  18 # for long, if your local time moves backwards, by moving timezones or
  19 # for an hour when daylight savings changes it, you will temporarily get
  20 # a more aggressive retention policy for the overlapping period, and
  21 # vice versa for the opposite timezone move. The alternative is using
  22 # long-iso, which puts timezone info into the timestamp, which means
  23 # that instead of shifting time, you shift the start of day/week/month
  24 # which is used for retention to your new local time, which means for
  25 # example, if you moved forward by 8 hours, the daily/weekly/monthly
  26 # retention will be 8 hours more aggressive since midnight is at a new
  27 # time, unless you fake the timzeone using the TZ env variable.
  28 # However, in the short term, there will be no inconsistencies.
  29 # I don't see any problem with shifting when the day starts for
  30 # retention, so I'm using long-iso.
  31
  32 target_host=frodo
  33 cat >/etc/btrbk.conf <<'EOF'
  34 ssh_identity /root/.ssh/id_rsa
  35 transaction_syslog daemon
  36
  37 # so we only run one at a time
  38 lockfile                   /var/lock/btrbk.lock
  39
  40 # default format of short does not accomidate hourly preservation setting
  41 timestamp_format long-iso
  42
  43 # only make a snapshot if things have changed
  44 snapshot_create onchange
  45 # much less snapshots because I have less space on the
  46 # local filesystem.
  47 snapshot_preserve 2h 2d
  48
  49 # so, total backups = ~89
  50 target_preserve 48h 14d 8w 24m
  51 target_preserve_min 6h
  52
  53 # if something fails and it's not obvious, try doing
  54 # btrbk -l debug -v dryrun
  55 EOF
  56
  57
  58 case $HOSTNAME in
  59     tp|x2)
  60         if ! timeout -s 9 10 ssh frodo :; then
  61             target_host=$HOME_DOMAIN
  62             cat >>/etc/btrbk.conf <<EOF
  63 ssh_port 2222
  64 EOF
  65         fi
  66         ;;
  67 esac
  68
  69 if [[ $HOSTNAME != frodo ]]; then
  70     remote_target="target send-receive ssh://${target_host}/mnt/root/${HOSTNAME}-btrbk"
  71 fi
  72
  73 target-section() {
  74     root=$1
  75     subvol=$2
  76     mountpoint $root &>/dev/null || return
  77     cat >>/etc/btrbk.conf <<EOF
  78 volume $root
  79 subvolume $subvol
  80 $remote_target
  81
  82 EOF
  83 }
  84
  85 target-section /mnt/iroot i
  86 target-section /mnt/root q
  87
  88 if $conf_only; then
  89     exit
  90 fi
  91
  92 if $dry_run; then
  93     btrbk -n run
  94 else
  95     btrbk -q run
  96 fi