zfs_clean_snap

#!/bin/sh
#
# destroy snapshots not corresponding to the expression given in the volume given
#

usage() {
  echo "usage: $0 [-r] [-g \"GREP_EXPR\"] [-d] [-h] KEEPEXPR ZFSVOLUME" 
  echo "eg: $0 5l10d5w3m2y ZLIP-ftp/sav"
  echo "  KEEPEXPR: [<nblast>l][<nbhours>h][<nbdays>d][<nbweeks>w][<nbmonths>m][<nbyears>y]"
  echo "  eg: 5h10d4w3m2y for 5 hours, 10 days, 4 weeks, 3 months and 2 years"
  echo "  eg: 4w3m2y for 4 weeks, 3 months and 2 years"
  echo "  eg: 8l3h3m2y for 8 last, 3 hours, 3 months and 2 years"
  echo ""
  echo "  -r (env CLEANSNAP_RECURSE): will destroy recursively (zfs destroy -r)"
  echo "  -R (env CLEANSNAP_RECURSE_MANUALLY): will destroy recursively (zfs destroy -r) AND re-search in each subvolume"
  echo "  -g GREP_EXPR (env CLEANSNAP_GREP): will use it to select snapshots (by default match GMT-YYYY.MM.DD-HH.mm.ss)"
  echo "  -v N (env CLEANSNAP_VERBOSE): will display more information (if N > 0 for now)"
  echo "  -d (env CLEANSNAP_FAKE): no destroy command will be launched for real, but displayed"
  echo "  -h you are here :)"
  exit ${1:-1}
}

CLEANSNAP_VERBOSE=${CLEANSNAP_VERBOSE:-0}
ORIGARGS=$@
while getopts rRg:dv:h option
do
  case $option in
    r)
      CLEANSNAP_RECURSE=yes
    ;;
    R)
      CLEANSNAP_RECURSE_MANUALLY=yes
      CLEANSNAP_RECURSE=yes
    ;;
    g)
      CLEANSNAP_GREP=$OPTARG
    ;;
    d)
      CLEANSNAP_FAKE=1
    ;;
    v)
      CLEANSNAP_VERBOSE=$OPTARG
    ;;
    h)
      usage 0
    ;;
  esac
done
# shift getopt args from ARGV
shift $(expr $OPTIND - 1)

if [ $# -ne 2 ]; then
  usage
fi
if ! ( echo $1 | egrep '^([[:digit:]]+l)?([[:digit:]]+h)?([[:digit:]]+d)?([[:digit:]]+w)?([[:digit:]]+m)?([[:digit:]]+y)?$' > /dev/null ) || \
  [ -z "$1" ]; then
  echo "expression \"$1\" doesn't match [<nblast>l][<nbhours>h][<nbdays>d][<nbweeks>w][<nbmonths>m][<nbyears>y]:("
  usage
fi

getsnapdate() {
  ZTIME=$(LC_TIME=C zfs list -H -o creation $1| cut -c 1-21 2>/dev/null)
  [ -z "$ZTIME" ] && return 1
  LC_TIME=C date -jnu -f '%a %b %e %R %Y' +%s "$(LC_TIME=C zfs list -H -o creation $1| cut -c 1-21)"
}
say() {
  if [ -z "$CLEANSNAP_FAKE" ]; then
    if [ -z "$TERM" ]; then
      echo "$0[$$]" $@ >> /var/log/clean_zfs_snaps.log
    else
      echo "$0[$$]" $@ | tee -a /var/log/clean_zfs_snaps.log
    fi
  else
    echo $@
  fi
}
doit() {
  say $@
  if [ -z "$CLEANSNAP_FAKE" ]; then
    eval $@
  fi
}
debug() {
  if [ $CLEANSNAP_VERBOSE -gt 0 ]; then
    [ -z "$TERM" ] && say $@ || echo $@
  fi
}
error_with_logs() {
  say $@;
  echo "zfs_clean_snap $EXPR $VOL: $*" | /usr/local/bin/mutt -s "Erreur de zfs_clean_snap sur $(hostname)" sysadm@ec-m.fr -a $(for log in $TODELLIST $CHECKLIST $FULLLIST $WORKLIST; do echo "$log "; done)
}

ID=$(echo $2 | sed 's@/@_@g')
export CLEANSNAP_RECURSE_MANUALLY CLEANSNAP_RECURSE CLEANSNAP_GREP CLEANSNAP_FAKE CLEANSNAP_VERBOSE ID

# lock (not more than one by pool)
if ! [ "$LOCKED" != "YAISSE" ]; then
  exec lockf -s -t 1600 /tmp/zfs_clean_snap_${ID}.lock $0 $*
fi

TODELLIST=/tmp/zfs_clean_snap_${ID}.todel
CHECKLIST=/tmp/zfs_clean_snap_${ID}.tocheck
FULLLIST=/tmp/zfs_clean_snap_${ID}.fullist
WORKLIST=/tmp/zfs_clean_snap_${ID}.list

for tmpfile in $TODELLIST $CHECKLIST $FULLLIST $WORKLIST; do
  if [ -f $tmpfile ]; then
    echo "derniere execution non finie: $tmpfile existe" 1>&2
    exit 1
  fi
  touch $tmpfile
done

say "$(date) $0 $*"

EXPR=$1
VOL=$2

NBLAST=${EXPR%%l*}
[ "$NBLAST" = "$EXPR" ] && NBLAST=0
EXPR=${EXPR##*l}
NBHOURS=${EXPR%%h*}
[ "$NBHOURS" = "$EXPR" ] && NBHOURS=0
EXPR=${EXPR##*h}
NBDAYS=${EXPR%%d*}
[ "$NBDAYS" = "$EXPR" ] && NBDAYS=0
EXPR=${EXPR##*d}
NBWEEKS=${EXPR%%w*}
[ "$NBWEEKS" = "$EXPR" ] && NBWEEKS=0
EXPR=${EXPR##*w}
NBMONTHS=${EXPR%%m*}
[ "$NBMONTHS" = "$EXPR" ] && NBMONTHS=0
EXPR=${EXPR##*m}
NBYEARS=${EXPR%%y*}
[ "$NBYEARS" = "$EXPR" ] && NBYEARS=0
#EXPR=${EXPR##*y}

debug "Will save $NBLAST last, $NBHOURS hours, $NBDAYS days, $NBWEEKS weeks, $NBMONTHS months and $NBYEARS years of snapshots"

GREPSNAP=${CLEANSNAP_GREP:-'GMT-2[0-9][0-9][0-9]\.[01][0-9]\.[0-3][0-9]-[0-2][0-9]\.[0-5][0-9]\.[0-5][0-9]$'}

OLDHOURLY=$(date -u -v -$(( NBHOURS +1 ))H +%s)
OLDDAILY=$(date -u -v -$(( NBDAYS +1 ))d +%s)
OLDWEEKLY=$(date -u -v -$(( NBWEEKS * 7 + 2 ))d +%s)
OLDMONTHLY=$(date -u -v -$(( NBMONTHS * 31 ))d +%s)
OLDYEARLY=$(date -u -v -$(( NBYEARS * 365 +30 ))d +%s)

# la fonction principale
# usage: cleanupvol volume list
cleanupvol() {
  volume=$1
  TMPLIST=$WORKLIST.tmp
  : > $TMPLIST
  local NBLAST NBHOURS NBDAYS NBWEEKS NBMONTHS NBYEARS
  SNAPNUM=$(grep "^$volume@" $WORKLIST | wc -l)
  grep "^$volume@" $WORKLIST | while read name; do
    # skip if already processed
    if grep -q "^$name" $CHECKLIST; then
      continue
    fi
    SNAPNUM=$(( $SNAPNUM - 1 ))
    ts=$(getsnapdate $name)
    [ -z "$ts" ] && continue
    KEEPIT=""
    # skip if format doesn't match
    if [ $? -ne 0 ] || [ -z "$ts" ]; then
      continue
    fi
    if [ $NBLAST -gt $SNAPNUM ]; then
      KEEPIT=$KEEPIT" last"
      NBLAST=$(($NBLAST - 1))
    fi
    if [ $NBHOURS -gt 0 ]; then
      if [ $ts -ge $OLDHOURLY ]; then
        if [ -z "$LASTHOUR" ]; then
          LASTHOUR=$ts
          KEEPIT=$KEEPIT" hourly"
          NBHOURS=$(($NBHOURS - 1))
        elif [ $ts -ge $(date -ju -f %s -v +55M +%s $LASTHOUR) ]; then
          LASTHOUR=$ts
          KEEPIT=$KEEPIT" hourly"
          NBHOURS=$(($NBHOURS - 1))
        fi
      fi
    fi
    # daily: 1 day after than $LASTDAY
    if [ $NBDAYS -gt 0 ]; then
      if [ $ts -ge $OLDDAILY ]; then
        if [ -z "$LASTDAY" ]; then
          LASTDAY=$ts
          KEEPIT=$KEEPIT" daily"
          NBDAYS=$(($NBDAYS - 1))
        elif [ $ts -ge $(date -ju -f %s -v +23H +%s $LASTDAY) ]; then
          LASTDAY=$ts
          KEEPIT=$KEEPIT" daily"
          NBDAYS=$(($NBDAYS - 1))
        fi
      fi
    fi
    # weekly: 1 week after than $LASTWEEK
    if [ $NBWEEKS -gt 0 ]; then
      if [ $ts -ge $OLDWEEKLY ]; then
        if [ -z "$LASTWEEK" ]; then
          LASTWEEK=$ts
          KEEPIT=$KEEPIT" weekly"
          NBWEEKS=$(($NBWEEKS - 1))
        elif [ $ts -ge $(date -ju -f %s -v +166H +%s $LASTWEEK) ]; then
          LASTWEEK=$ts
          KEEPIT=$KEEPIT" weekly"
          NBWEEKS=$(($NBWEEKS - 1))
        fi
      fi
    fi
    # monthly: 1 month after than $LASTMONTH
    if [ $NBMONTHS -gt 0 ]; then
      if [ $ts -ge $OLDMONTHLY ]; then
        if [ -z "$LASTMONTH" ]; then
          LASTMONTH=$ts
          KEEPIT=$KEEPIT" monthly"
          NBMONTHS=$(($NBMONTHS - 1))
        elif [ $ts -ge $(date -ju -f %s -v +30d +%s $LASTMONTH) ]; then
          LASTMONTH=$ts
          KEEPIT=$KEEPIT" monthly"
          NBMONTHS=$(($NBMONTHS - 1))
        fi
      fi
    fi
    # yearly: 1 year after than $LASTYEAR
    if [ $NBYEARS -gt 0 ]; then
      if [ $ts -ge $OLDYEARLY ]; then
        if [ -z "$LASTYEAR" ]; then
          LASTYEAR=$ts
          KEEPIT=$KEEPIT" yearly"
          NBYEARS=$(($NBYEARS - 1))
        elif [ $ts -ge $(date -ju -f %s -v +364d +%s $LASTYEAR) ]; then
          LASTYEAR=$ts
          KEEPIT=$KEEPIT" yearly"
          NBYEARS=$(($NBYEARS - 1))
        fi
      fi
    fi
    if [ -n "$KEEPIT" ]; then
      debug "Keeping $name ($KEEPIT)"
    else
      debug "will destroy ${CLEANSNAP_RECURSE:+-r} $name ($ts)"
      echo "$name" >> $TODELLIST
      if [ -n "$CLEANSNAP_RECURSE" ]; then
        grep -v "^${volume}.*@${name#*@}$" $WORKLIST > $TMPLIST
        grep "^${volume}.*@${name#*@}$" $WORKLIST >> $CHECKLIST
      else
        grep -v "^${name}$" $WORKLIST > $TMPLIST
        grep "^${name}$" $WORKLIST >> $CHECKLIST
      fi
    fi
  done
  test -s $TMPLIST && mv $TMPLIST $WORKLIST || rm $TMPLIST
}

# c'est parti
[ "${CLEANSNAP_RECURSE_MANUALLY}" = "yes" ] || LIMITOPT=" -d1"
zfs list -t snapshot -o name -r${LIMITOPT} $VOL | grep '^'$VOL'.*@'$GREPSNAP > $FULLLIST
cp $FULLLIST $WORKLIST
for vol in $(sed 's/@.*$//' $FULLLIST | uniq); do
  debug "Cleaning $vol"
  cleanupvol $vol
done
ERRS=""
if [ -s $TODELLIST ]; then
  # A ce moment on efface pour de vrai
  for zsnap in $(cat $TODELLIST); do 
    if ! doit "zfs destroy -d${CLEANSNAP_RECURSE:+r} $zsnap"; then
      ERRS=$ERRS" "$zsnap
    fi
  done
  if [ ! -z "$ERRS" ]; then
    error_with_logs "Erreurs a la suppression de $ERRS :("
  else
    # check
    debug "checking"
    zfs list -t snapshot -o name -r $VOL | grep '^'$VOL'.*@'$GREPSNAP > $WORKLIST
    CHECK=$(cat $CHECKLIST $WORKLIST | sort | uniq -d)
    if [ -n "$CHECK" ]; then
      debug "checks: snapshots en trop a la fin: $CHECK"
    fi
    say "done :)"
  fi
fi
rm $FULLLIST $WORKLIST $TODELLIST $CHECKLIST