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 usage() {
   9     echo "top of script file:"
  10     sed -n '1,/^[# ]*end command line/{p;b};q' "$0"
  11     exit $1
  12 }
  13
  14 conf_only=false
  15 dry_run=false # mostly for testing
  16
  17 temp=$(getopt -l help,long-opt hcnt "$@") || usage 1
  18 eval set -- "$temp"
  19 while true; do
  20     case $1 in
  21         -c) conf_only=true; shift ;;
  22         -n) dry_run=true; dry_run_arg=-n; shift ;;
  23         -t) IFS=, targets=($2); shift 2 ;;
  24         -h|--help) usage ;;
  25         --) shift; break ;;
  26         *) echo "$0: Internal error!" ; exit 1 ;;
  27     esac
  28 done
  29 read primary <<<"$@"
  30
  31 ##### end command line parsing ########
  32
  33 sed="sed -r --follow-symlinks"
  34 last_snaps=()
  35
  36 target-section() {
  37     local root=$1
  38     local subvol=$2
  39     mountpoint $root &>/dev/null || return
  40     cat >>/etc/btrbk.conf <<EOF
  41 volume $root
  42 subvolume $subvol
  43 $remote_target
  44
  45 EOF
  46 }
  47
  48 rsync-dirs() {
  49     local host=$1
  50     local path=$2
  51     rsync $dry_run_arg -ahi --relative --delete "$path" "root@$host:/"
  52 }
  53
  54 last-snap() {
  55     vol=${1##*/}
  56     cd /mnt/root
  57     last_snap=$(
  58         for f in $vol.20*; do
  59             printf "%s %s\n" $(date -d $(sed -r  's/(.{4})(..)(.{5})(..)(.*)/\1-\2-\3:\4:\5/' <<<${f#$vol.}) +%s) $f
  60         done | sort -r | head -n 1 | awk '{print $2}'
  61              )
  62     last_snaps+=($last_snap)
  63 }
  64
  65 # note q is owned by root:1000
  66 # note p is owned 1000:1000 and chmod 700
  67 mountpoints=(/q)
  68 if mountpoint /p; then
  69     mountpoints+=(/p)
  70 fi
  71
  72 if [[ ! $targets ]]; then
  73     case $HOSTNAME in
  74         tp|x2)
  75             if ! timeout -s 9 10 ssh frodo :; then
  76                 targets=($HOME_DOMAIN)
  77             fi
  78             ;;
  79     esac
  80     targets=(frodo)
  81 fi
  82
  83
  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: setup sync systemd timer on $primary, once per hour.
  87 # todo: setup lock so that if this is already running, we exit out, so
  88 # that manual runs don't interfere with cronjobs.
  89 if [[ $primary ]] && ! $dry_run; then
  90     for m in ${mountpoints[@]}; do
  91         # note, this won't work for /i, due to path being /mnt/iroot
  92         # todo: include /i for treetowl/frodo
  93         btrfs property set -ts /mnt/root$m ro true
  94         ssh root@$primary bash <<EOF
  95 set -ex
  96 umount $m
  97 [[ -e /mnt/root$m ]] || exit 0
  98 btrfs sub del /mnt/root$m
  99 EOF
 100     done
 101 fi
 102
 103 for tg in ${targets[@]}; do
 104     cat >/etc/btrbk.conf <<'EOF'
 105 ssh_identity /root/.ssh/id_rsa
 106 transaction_syslog daemon
 107
 108 # so we only run one at a time
 109 lockfile                   /var/lock/btrbk.lock
 110
 111 # default format of short does not accomidate hourly preservation setting
 112 timestamp_format long-iso
 113
 114 # only make a snapshot if things have changed
 115 snapshot_create onchange
 116 # much less snapshots because I have less space on the
 117 # local filesystem.
 118 snapshot_preserve 2h 2d
 119
 120 # so, total backups = ~89
 121 target_preserve 48h 14d 8w 24m
 122 target_preserve_min 6h
 123
 124 # if something fails and it's not obvious, try doing
 125 # btrbk -l debug -v dryrun
 126 EOF
 127
 128     remote_target="target send-receive ssh://${tg}/mnt/root"
 129
 130     if [[ $tg == frodo && $HOSTNAME == treetowl ]]; then
 131         target-section /mnt/iroot i
 132     fi
 133     for m in ${mountpoints[@]}; do
 134         target-section /mnt/root ${m##*/}
 135     done
 136 done
 137
 138 if $conf_only; then
 139     exit
 140 fi
 141
 142 if $dry_run; then
 143     btrbk -n run
 144 else
 145     btrbk -q run
 146 fi
 147
 148 # if we have /p, rsync to targets without /p
 149 if mountpoint /p; then
 150     for tg in ${targets[@]}; do
 151         case $tg in
 152             tp|li|lk)
 153                 # todo, test this
 154                 for x in /p/c/machine_specific/*.hosts; do
 155                     if grep -qxF $tg $x; then
 156                         dir=${x%.hosts}
 157                         rsync-dirs ${dir##*/} $dir
 158                     fi
 159                 done
 160                 ;;
 161         esac
 162     done
 163 fi
 164
 165 first_root=$(awk '$2 == "/mnt/root" {print $1}' /etc/mtab)
 166
 167 # make $primary have the rw snapshot
 168 if [[ $primary ]] && ! $dry_run; then
 169     fstab=()
 170     for m in ${mountpoints[@]}; do
 171         last-snap $m
 172         fstab+=("$first_root  $m  btrfs  noatime,subvol=$last_snap  0 0")
 173     done
 174
 175     printf "%s\n" "${fstab[@]}" | cedit /etc/fstab
 176     for d in ${mountpoints[@]}; do
 177         mount $d
 178         btrfs sub del /mnt/root$d
 179     done
 180     ssh root@primary bash -s "${mountpoints[*]}" "${last_snaps[*]}" <<'EOF'
 181 set -xe
 182 mountpoints=($1)
 183 last_snaps=($2)
 184 first_root=$(awk '$2 == "/mnt/root" {print $1}' /etc/mtab)
 185 for ((i=0; i < ${#mountpoints[@]}; i++)); do
 186   m=${mountpoints[i]}
 187   vol=${m##*/}
 188   fstab+=("$first_root $m  btrfs  noatime,subvol=$vol  0 0")
 189   cd /mnt/root
 190   btrfs sub snapshot ${last_snaps[i]} $vol
 191   mount $m
 192 done
 193 EOF
 194 fi
 195
 196
 197 # background on btrbk timezones. with short/long, timestamps use local time.
 198 # for long, if your local time moves backwards, by moving timezones or
 199 # for an hour when daylight savings changes it, you will temporarily get
 200 # a more aggressive retention policy for the overlapping period, and
 201 # vice versa for the opposite timezone move. The alternative is using
 202 # long-iso, which puts timezone info into the timestamp, which means
 203 # that instead of shifting time, you shift the start of day/week/month
 204 # which is used for retention to your new local time, which means for
 205 # example, if you moved forward by 8 hours, the daily/weekly/monthly
 206 # retention will be 8 hours more aggressive since midnight is at a new
 207 # time, unless you fake the timzeone using the TZ env variable.
 208 # However, in the short term, there will be no inconsistencies.
 209 # I don't see any problem with shifting when the day starts for
 210 # retention, so I'm using long-iso.