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+# -*- mode: sh; sh-basic-offset: 3; indent-tabs-mode: nil; -*-
+
+###############################################################
+#
+# This handler slowly creates a backup of each user's maildir
+# to a remote server. It is designed to be run with low overhead
+# in terms of cpu and bandwidth so it runs pretty slow.
+# Hardlinking is used to save storage space.
+#
+# each users maildir will contain these files:
+# daily.1
+# daily.2
+# daily.3
+# weekly.1
+# weekly.2
+# monthly.1
+# if keepdaily is 3, keepweekly is 2, and keepmonthly is 1.
+# the actual maildir is stored within each snapshot directory.
+#
+# The basic algorithm is to rsync each maildir individually,
+# and to use hard links for retaining historical data.
+#
+# We handle each maildir individually because it becomes very
+# unweldy to hardlink and rsync many hundreds of thousands
+# of files at once. It is much faster to take on smaller
+# chunks at a time.
+#
+# For the backup rotation to work, destuser must be able to run
+# arbitrary bash commands on the desthost.
+#
+# Any maildir which is deleted from the source will be moved to
+# "deleted" directory in the destination. It is up to you to
+# periodically remove this directory or old maildirs in it.
+#
+##############################################################
+
+getconf rotate yes
+getconf remove yes
+getconf backup yes
+
+getconf loadlimit 5
+getconf speedlimit 0
+getconf keepdaily 5
+getconf keepweekly 3
+getconf keepmonthly 1
+
+getconf srcdir /var/maildir
+getconf destdir
+getconf desthost
+getconf destport 22
+getconf destuser
+
+getconf multiconnection notset
+
+letters="a b c d e f g h i j k l m n o p q r s t u v w x y z"
+failedcount=0
+# strip trailing /
+destdir=${destdir%/}
+srcdir=${srcdir%/}
+
+# used for testing
+#getconf testuser elijah
+
+[ -d $srcdir ] || fatal "source directory $srcdir doesn't exist"
+
+[ "$multiconnection" == "notset" ] && fatal "The maildir handler uses a very different destination format. See the example .maildir for more information"
+
+[ ! $test ] || testflags="--dry-run -v"
+rsyncflags="$testflags -e 'ssh -p $destport' -r -v --ignore-existing --delete --size-only --bwlimit=$speedlimit"
+excludes="--exclude '.Trash/\*' --exclude '.Mistakes/\*' --exclude '.Spam/\*'"
+
+##################################################################
+### FUNCTIONS
+
+function do_user() {
+ local user=$1
+ local btype=$2
+ local letter=${user:0:1}
+ local source="$srcdir/$letter/$user/"
+ local target="$destdir/$letter/$user/$btype.1"
+ if [ ! -d $source ]; then
+ warning "maildir $source not found"
+ return
+ fi
+
+ debug "syncing"
+ ret=`$RSYNC -e "ssh -p $destport" -r \
+ --links --ignore-existing --delete --size-only --bwlimit=$speedlimit \
+ --exclude '.Trash/*' --exclude '.Mistakes/*' --exclude '.Spam/*' \
+ $source $destuser@$desthost:$target \
+ 2>&1`
+ ret=$?
+ # ignore 0 (success) and 24 (file vanished before it could be copied)
+ if [ $ret != 0 -a $ret != 24 ]; then
+ warning "rsync $user failed"
+ warning " returned: $ret"
+ let "failedcount = failedcount + 1"
+ if [ $failedcount -gt 100 ]; then
+ fatal "100 rsync errors -- something is not working right. bailing out."
+ fi
+ fi
+ ssh -o PasswordAuthentication=no $desthost -l $destuser "date +%c%n%s > $target/created"
+}
+
+# remove any maildirs from backup which might have been deleted
+# and add new ones which have just been created.
+# (actually, it just moved them to the directory "deleted")
+
+function do_remove() {
+ local tmp1=`maketemp maildir-tmp-file`
+ local tmp2=`maketemp maildir-tmp-file`
+
+ ssh -p $destport $destuser@$desthost mkdir -p "$destdir/deleted"
+ for i in a b c d e f g h i j k l m n o p q r s t u v w x y z; do
+ ls -1 "$srcdir/$i/" | sort > $tmp1
+ ssh -p $destport $destuser@$desthost ls -1 "$destdir/$i/" | sort > $tmp2
+ for deluser in `join -v 2 $tmp1 $tmp2`; do
+ [ "$deluser" != "" ] || continue
+ info "removing $destuser@$desthost:$destdir/$i/$deluser/"
+ ssh -p $destport $destuser@$desthost mv "$destdir/$i/$deluser/" "$destdir/deleted"
+ done
+ done
+ rm $tmp1
+ rm $tmp2
+}
+
+function do_rotate() {
+ [ "$rotate" == "yes" ] || return;
+ local user=$1
+ local letter=${user:0:1}
+ local backuproot="$destdir/$letter/$user"
+(
+ ssh -T -o PasswordAuthentication=no $desthost -l $destuser <<EOF
+##### BEGIN REMOTE SCRIPT #####
+ seconds_daily=86400
+ seconds_weekly=604800
+ seconds_monthly=2628000
+ keepdaily=$keepdaily
+ keepweekly=$keepweekly
+ keepmonthly=$keepmonthly
+ now=\`date +%s\`
+
+ if [ ! -d "$backuproot" ]; then
+ echo "Debug: skipping rotate of $user. $backuproot doesn't exist."
+ exit
+ fi
+ for rottype in daily weekly monthly; do
+ seconds=\$((seconds_\${rottype}))
+
+ dir="$backuproot/\$rottype"
+ if [ ! -d \$dir.1 ]; then
+ echo "Debug: \$dir.1 does not exist, skipping."
+ continue 1
+ elif [ ! -f \$dir.1/created ]; then
+ echo "Warning: \$dir.1/created does not exist. This backup may be only partially completed. Skipping rotation."
+ continue 1
+ fi
+
+ # Rotate the current list of backups, if we can.
+ oldest=\`find $backuproot -type d -maxdepth 1 -name \$rottype'.*' | @SED@ 's/^.*\.//' | sort -n | tail -1\`
+ #echo "Debug: oldest \$oldest"
+ [ "\$oldest" == "" ] && oldest=0
+ for (( i=\$oldest; i > 0; i-- )); do
+ if [ -d \$dir.\$i ]; then
+ if [ -f \$dir.\$i/created ]; then
+ created=\`tail -1 \$dir.\$i/created\`
+ else
+ created=0
+ fi
+ cutoff_time=\$(( now - (seconds*(i-1)) ))
+ if [ ! \$created -gt \$cutoff_time ]; then
+ next=\$(( i + 1 ))
+ if [ ! -d \$dir.\$next ]; then
+ echo "Debug: \$rottype.\$i --> \$rottype.\$next"
+ mv \$dir.\$i \$dir.\$next
+ date +%c%n%s > \$dir.\$next/rotated
+ else
+ echo "Debug: skipping rotation of \$dir.\$i because \$dir.\$next already exists."
+ fi
+ else
+ echo "Debug: skipping rotation of \$dir.\$i because it was created" \$(( (now-created)/86400)) "days ago ("\$(( (now-cutoff_time)/86400))" needed)."
+ fi
+ fi
+ done
+ done
+
+ max=\$((keepdaily+1))
+ if [ \( \$keepweekly -gt 0 -a -d $backuproot/daily.\$max \) -a ! -d $backuproot/weekly.1 ]; then
+ echo "Debug: daily.\$max --> weekly.1"
+ mv $backuproot/daily.\$max $backuproot/weekly.1
+ date +%c%n%s > $backuproot/weekly.1/rotated
+ fi
+
+ max=\$((keepweekly+1))
+ if [ \( \$keepmonthly -gt 0 -a -d $backuproot/weekly.\$max \) -a ! -d $backuproot/monthly.1 ]; then
+ echo "Debug: weekly.\$max --> monthly.1"
+ mv $backuproot/weekly.\$max $backuproot/monthly.1
+ date +%c%n%s > $backuproot/monthly.1/rotated
+ fi
+
+ for rottype in daily weekly monthly; do
+ max=\$((keep\${rottype}+1))
+ dir="$backuproot/\$rottype"
+ oldest=\`find $backuproot -type d -maxdepth 1 -name \$rottype'.*' | @SED@ 's/^.*\.//' | sort -n | tail -1\`
+ [ "\$oldest" == "" ] && oldest=0
+ # if we've rotated the last backup off the stack, remove it.
+ for (( i=\$oldest; i >= \$max; i-- )); do
+ if [ -d \$dir.\$i ]; then
+ if [ -d $backuproot/rotate.tmp ]; then
+ echo "Debug: removing rotate.tmp"
+ rm -rf $backuproot/rotate.tmp
+ fi
+ echo "Debug: moving \$rottype.\$i to rotate.tmp"
+ mv \$dir.\$i $backuproot/rotate.tmp
+ fi
+ done
+ done
+####### END REMOTE SCRIPT #######
+EOF
+) | (while read a; do passthru $a; done)
+
+}
+
+
+function setup_remote_dirs() {
+ local user=$1
+ local backuptype=$2
+ local letter=${user:0:1}
+ local dir="$destdir/$letter/$user/$backuptype"
+ local tmpdir="$destdir/$letter/$user/rotate.tmp"
+(
+ ssh -T -o PasswordAuthentication=no $desthost -l $destuser <<EOF
+ if [ ! -d $destdir ]; then
+ echo "Fatal: Destination directory $destdir does not exist on host $desthost."
+ exit 1
+ elif [ -d $dir.1 ]; then
+ if [ -f $dir.1/created ]; then
+ echo "Warning: $dir.1 already exists. Overwriting contents."
+ else
+ echo "Warning: we seem to be resuming a partially written $dir.1"
+ fi
+ else
+ if [ -d $tmpdir ]; then
+ mv $tmpdir $dir.1
+ if [ \$? == 1 ]; then
+ echo "Fatal: could mv $destdir/rotate.tmp $dir.1 on host $desthost"
+ exit 1
+ fi
+ else
+ mkdir --parents $dir.1
+ if [ \$? == 1 ]; then
+ echo "Fatal: could not create directory $dir.1 on host $desthost"
+ exit 1
+ fi
+ fi
+ if [ -d $dir.2 ]; then
+ echo "Debug: update links $backuptype.2 --> $backuptype.1"
+ cp -alf $dir.2/. $dir.1
+ #if [ \$? == 1 ]; then
+ # echo "Fatal: could not create hard links to $dir.1 on host $desthost"
+ # exit 1
+ #fi
+ fi
+ fi
+ [ -f $dir.1/created ] && rm $dir.1/created
+ [ -f $dir.1/rotated ] && rm $dir.1/rotated
+ exit 0
+EOF
+) | (while read a; do passthru $a; done)
+
+ if [ $? == 1 ]; then exit; fi
+}
+
+function start_mux() {
+ if [ "$multiconnection" == "yes" ]; then
+ debug "Starting dummy ssh connection"
+ ssh -p $destport $destuser@$desthost sleep 1d &
+ sleep 1
+ fi
+}
+
+function end_mux() {
+ if [ "$multiconnection" == "yes" ]; then
+ debug "Stopping dummy ssh connection"
+ ssh -p $destport $destuser@$desthost pkill sleep
+ fi
+}
+
+###
+##################################################################
+
+# see if we can login
+debug "ssh -o PasswordAuthentication=no $desthost -l $destuser 'echo -n 1'"
+if [ ! $test ]; then
+ result=`ssh -o PasswordAuthentication=no $desthost -l $destuser 'echo -n 1' 2>&1`
+ if [ "$result" != "1" ]; then
+ fatal "Can't connect to $desthost as $destuser."
+ fi
+fi
+
+end_mux
+start_mux
+
+## SANITY CHECKS ##
+status=`ssh -p $destport $destuser@$desthost "[ -d \"$destdir\" ] && echo 'ok'"`
+if [ "$status" != "ok" ]; then
+ end_mux
+ fatal "Destination directory $destdir doesn't exist!"
+ exit
+fi
+
+### REMOVE OLD MAILDIRS ###
+
+if [ "$remove" == "yes" ]; then
+ do_remove
+fi
+
+### MAKE BACKUPS ###
+
+if [ "$backup" == "yes" ]; then
+ if [ $keepdaily -gt 0 ]; then btype=daily
+ elif [ $keepweekly -gt 0 ]; then btype=weekly
+ elif [ $keepmonthly -gt 0 ]; then btype=monthly
+ else fatal "keeping no backups"; fi
+
+ if [ "$testuser" != "" ]; then
+ cd "$srcdir/${user:0:1}"
+ do_rotate $testuser
+ setup_remote_dirs $testuser $btype
+ do_user $testuser $btype
+ else
+ for i in $letters; do
+ [ -d "$srcdir/$i" ] || fatal "directory $srcdir/$i not found."
+ cd "$srcdir/$i"
+ debug $i
+ for user in `ls -1`; do
+ [ "$user" != "" ] || continue
+ debug $user
+ do_rotate $user
+ setup_remote_dirs $user $btype
+ do_user $user $btype
+ done
+ done
+ fi
+fi
+
+end_mux
+