# -*- 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%/} [ -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 < 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 < $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