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Diffstat (limited to 'handlers/maildir.in')
| -rw-r--r-- | handlers/maildir.in | 348 |
1 files changed, 348 insertions, 0 deletions
diff --git a/handlers/maildir.in b/handlers/maildir.in new file mode 100644 index 0000000..4b98deb --- /dev/null +++ b/handlers/maildir.in @@ -0,0 +1,348 @@ +# -*- 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 + |