diff options
| -rw-r--r-- | handlers/dsync.in | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/handlers/dsync.in b/handlers/dsync.in new file mode 100644 index 0000000..bf7b51d --- /dev/null +++ b/handlers/dsync.in @@ -0,0 +1,357 @@ +# -*- mode: sh; sh-basic-offset: 3; indent-tabs-mode: nil; -*- +# vim: set filetype=sh sw=3 sts=3 expandtab autoindent: + +############################################################### +# +# This handler uses dovecot (version 2 or later) dsync backup +# to backup mail to a remote server. +# +# Source and destination directories are typically configured +# via the dovecot configuration, but can be overridden using +# the settings here. +# +# if the configuration is setup to have keepdaily at 3, +# keepweekly is 2, and keepmonthly is 1, then each user's +# maildir backup snapshot directory will contain these files: +# daily.1 +# daily.2 +# daily.3 +# weekly.1 +# weekly.2 +# monthly.1 +# +# The basic algorithm is to dsync each user individually, +# and to use hard links for retaining historical data. +# +# For the backup rotation to work, destuser must be able to run +# arbitrary bash commands on the desthost. +# +# If 'remove' is set to 'yes' (default), then any mail directory +# which is deleted from the source will be moved to a "deleted" +# directory in the destination. It is up to you to periodically +# remove this directory or old maildirs in it. +# +# Limitations: +# . because we are not dynamically looking up anything with +# dovecot's userdb, we expect all data to be under the same +# tree on both the source and destination +# +# . we are assuming a backup to a backup server, so the +# destination host should have its dovecot mail_location +# configured to put the mail into +# $stripped_destdir/$letter/$user/$current_backup +# +############################################################## + +getconf rotate yes +getconf remove yes +getconf backup yes + +getconf keepdaily 5 +getconf keepweekly 3 +getconf keepmonthly 1 + +getconf srcconffile +getconf destconffile +getconf srcdir +getconf destdir +getconf current_backup current_backup +getconf desthost +getconf destport 22 +getconf destuser +getconf destid_file /root/.ssh/id_rsa +getconf sshoptions + +failedcount=0 + +# strip leading mailbox specifier (eg. mdbox:; maildir:, etc) +stripped_destdir=${destdir/*:/} +stripped_srcdir=${srcdir/*:/} + +# strip trailing / +destdir=${destdir%/} +srcdir=${srcdir%/} + +if [ ! -n $destdir ]; then + destdir='-o mail_location=$destdir' +fi +if [ ! -n $srcdir ]; then + srcdir='-o mail_location=$srcdir' +fi + +if [ ! -n $srcconffile ]; then + srcconffile='-c $srcconffile' +fi + +if [ ! -n $destconffile ]; then + destconffile='-c $destconffile' +fi + +[ -d $stripped_srcdir ] || fatal "source directory $srcdir doesn't exist" + + +################################################################## +### FUNCTIONS + +function do_user() { + local user=$1 + local btype=$2 + local letter=${user:0:1} + local target="$stripped_destdir/$letter/$user/$current_backup" + + debug "syncing" + while [ $failedcount -lt 4 ]; do + debug $DSYNC $testflags -u $user backup $srcconffile $srcdir \ + ssh -i $destid_file $destuser@$desthost $DSYNC $destconffile \ + -u $user $destdir 2>&1 + ret=`$DSYNC $testflags -u $user backup $srcconffile $srcdir \ + ssh -i $destid_file $destuser@$desthost $DSYNC $destconffile \ + -u $user $destdir 2>&1` + ret=$? + if [ $ret == 2 ]; then + # dsync needs to be run again + let "failedcount = failedcount + 1" + elif [ $ret == 0 ]; then + # things worked, so we break out of the loop + let "failedcount = 4" + # move the directory to the $btype.1 and make a 'created' file + ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions "mv $target ../$btype.1" + ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions "date +%c%n%s > ../$btype.1/created" + elif [ $ret != 0 ]; then + # things did not work in a good way, report it and try again + warning "dsync $user failed" + warning " returned: $ret" + let "failedcount = failedcount + 1" + fi + + if [ $failedcount -gt 4 ]; then + fatal "dsync failed 3 times for this user -- something is not working right. bailing out." + fi + done +} + +# 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 dsync-tmp-file` + local tmp2=`maketemp dsync-tmp-file` + + ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost mkdir -p "${stripped_destdir}/deleted" + cd "$stripped_srcdir" + for userdir in `ls -d1 */`; do + ls -1 "$stripped_srcdir/$userdir" | sort > $tmp1 + ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost ls -1 "$stripped_destdir/$userdir" | sort > $tmp2 + for deluser in `join -v 2 $tmp1 $tmp2`; do + [ "$deluser" != "" ] || continue + info "removing $destuser@$desthost:$stripped_destdir/$userdir$deluser/" + ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost mv "$stripped_destdir/$userdir$deluser/" "$stripped_destdir/deleted" + ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost "date +%c%n%s > '$stripped_destdir/deleted/$deluser/deleted_on'" + done + done + rm $tmp1 + rm $tmp2 +} + +function do_rotate() { + [ "$rotate" == "yes" ] || return; + local user=$1 + local letter=${user:0:1} + local backuproot="$stripped_destdir/$letter/$user" + local target="$stripped_destdir/$letter/$user/$current_backup" +( + ssh -T -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions <<EOF +##### BEGIN REMOTE SCRIPT ##### + seconds_daily=86400 + seconds_weekly=604800 + seconds_monthly=2628000 + keepdaily=$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 + fi + + if [ -f \$target ]; then + echo "Warning: \$target exists. Previous backup did not complete properly. Skipping rotation." + continue 1 + fi + + # Rotate the current list of backups, if we can. + oldest=\`find $backuproot -maxdepth 1 -type d -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 -maxdepth 1 -type d -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="$stripped_destdir/$letter/$user/$backuptype" + local tmpdir="$stripped_destdir/$letter/$user/rotate.tmp" +( + ssh -T -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions <<EOF + if [ ! -d $stripped_destdir ]; then + echo "Fatal: Destination directory $stripped_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 $stripped_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 +} + +### +################################################################## + +# see if we can login +debug "ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions 'echo -n 1'" +if [ ! $test ]; then + result=`ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file $sshoptions 'echo -n 1' 2>&1` + if [ "$result" != "1" ]; then + fatal "Can't connect to $desthost as $destuser using $destid_file." + fi +fi + +## SANITY CHECKS ## +status=`ssh -p $destport -i $destid_file $sshoptions $destuser@$desthost "[ -d \"$stripped_destdir\" ] && echo 'ok'"` +if [ "$status" != "ok" ]; then + fatal "Destination directory $stripped_destdir doesn't exist!" + exit +fi + +### REMOVE OLD MAILDIRS ### + +if [ "$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 "$stripped_srcdir/${user:0:1}" + do_rotate $testuser + setup_remote_dirs $testuser $btype + do_user $testuser $btype + else + [ -d "$stripped_srcdir" ] || fatal "directory $stripped_srcdir not found." + for user in `$DOVEADM user \* | cut -d@ -f1` + do + debug $user + [ "$user" != "" ] || continue + do_rotate $user + setup_remote_dirs $user $btype + do_user $user $btype + done + fi +fi + |