handlers/maildir.in

   1 # -*- mode: sh; sh-basic-offset: 3; indent-tabs-mode: nil; -*-
   2
   3 ###############################################################
   4 #
   5 #  This handler slowly creates a backup of each user's maildir
   6 #  to a remote server. It is designed to be run with low overhead
   7 #  in terms of cpu and bandwidth so it runs pretty slow.
   8 #  Hardlinking is used to save storage space.
   9 #
  10 #  This handler expects that your maildir directory structure is
  11 #  either one of the following:
  12 #
  13 #  1. /$srcdir/[a-zA-Z0-9]/$user for example:
  14 #  /var/maildir/a/anarchist
  15 #  /var/maildir/a/arthur
  16 #  ...
  17 #  /var/maildir/Z/Zaphod
  18 #  /var/maildir/Z/Zebra
  19 #
  20 #  2. or the following:
  21 #  /var/maildir/domain.org/user1
  22 #  /var/maildir/domain.org/user2
  23 #  ...
  24 #  /var/maildir/anotherdomain.org/user1
  25 #  /var/maildir/anotherdomain.org/user2
  26 #  ...
  27 #
  28 #  if the configuration is setup to have keepdaily at 3,
  29 #  keepweekly is 2, and keepmonthly is 1, then each user's
  30 #  maildir backup snapshot directory will contain these files:
  31 #    daily.1
  32 #    daily.2
  33 #    daily.3
  34 #    weekly.1
  35 #    weekly.2
  36 #    monthly.1
  37 #
  38 #  The basic algorithm is to rsync each maildir individually,
  39 #  and to use hard links for retaining historical data.
  40 #
  41 #  We handle each maildir individually because it becomes very
  42 #  unweldy to hardlink and rsync many hundreds of thousands
  43 #  of files at once. It is much faster to take on smaller
  44 #  chunks at a time.
  45 #
  46 #  For the backup rotation to work, destuser must be able to run
  47 #  arbitrary bash commands on the desthost.
  48 #
  49 #  Any maildir which is deleted from the source will be moved to
  50 #  "deleted" directory in the destination. It is up to you to
  51 #  periodically remove this directory or old maildirs in it.
  52 #
  53 ##############################################################
  54
  55 getconf rotate yes
  56 getconf remove yes
  57 getconf backup yes
  58
  59 getconf loadlimit 5
  60 getconf speedlimit 0
  61 getconf keepdaily 5
  62 getconf keepweekly 3
  63 getconf keepmonthly 1
  64
  65 getconf srcdir /var/maildir
  66 getconf destdir
  67 getconf desthost
  68 getconf destport 22
  69 getconf destuser
  70 getconf destid_file /root/.ssh/id_rsa
  71
  72 getconf multiconnection notset
  73
  74 failedcount=0
  75 # strip trailing /
  76 destdir=${destdir%/}
  77 srcdir=${srcdir%/}
  78
  79 [ -d $srcdir ] || fatal "source directory $srcdir doesn't exist"
  80
  81 [ "$multiconnection" == "notset" ] && fatal "The maildir handler uses a very different destination format. See the example .maildir for more information"
  82
  83 if [ $test ]; then
  84    testflags="--dry-run -v"
  85 fi
  86
  87 rsyncflags="$testflags -e 'ssh -p $destport -i $destid_file' -r -v --ignore-existing --delete --size-only --bwlimit=$speedlimit"
  88 excludes="--exclude '.Trash/\*' --exclude '.Mistakes/\*' --exclude '.Spam/\*'"
  89
  90 ##################################################################
  91 ### FUNCTIONS
  92
  93 function do_user() {
  94         local user=$1
  95         local btype=$2
  96         local userdir=${3%/}
  97         local source="$srcdir/$userdir/$user/"
  98         local target="$destdir/$userdir/$user/$btype.1"
  99         if [ ! -d $source ]; then
 100           warning "maildir $source not found"
 101           return
 102     fi
 103
 104         debug "syncing"
 105         ret=`$RSYNC -e "ssh -p $destport -i $destid_file" -r \
 106                 --links --ignore-existing --delete --size-only --bwlimit=$speedlimit \
 107                 --exclude '.Trash/*' --exclude '.Mistakes/*' --exclude '.Spam/*' \
 108                 $source $destuser@$desthost:$target \
 109                 2>&1`
 110         ret=$?
 111         # ignore 0 (success) and 24 (file vanished before it could be copied)
 112         if [ $ret != 0 -a $ret != 24 ]; then
 113                 warning "rsync $user failed"
 114                 warning "  returned: $ret"
 115                 let "failedcount = failedcount + 1"
 116                 if [ $failedcount -gt 100 ]; then
 117                         fatal "100 rsync errors -- something is not working right. bailing out."
 118                 fi
 119         fi
 120         ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file "date +%c%n%s > $target/created"
 121 }
 122
 123 # remove any maildirs from backup which might have been deleted
 124 # and add new ones which have just been created.
 125 # (actually, it just moved them to the directory "deleted")
 126
 127 function do_remove() {
 128         local tmp1=`maketemp maildir-tmp-file`
 129         local tmp2=`maketemp maildir-tmp-file`
 130
 131         ssh -p $destport -i $destid_file $destuser@$desthost mkdir -p "$destdir/deleted"
 132         cd "$srcdir"
 133         for userdir in `ls -d1 */`; do
 134            ls -1 "$srcdir/$userdir" | sort > $tmp1
 135            ssh -p $destport $destuser@$desthost ls -1 "$destdir/$userdir" | sort > $tmp2
 136                 for deluser in `join -v 2 $tmp1 $tmp2`; do
 137                         [ "$deluser" != "" ] || continue
 138                         info "removing $destuser@$desthost:$destdir/$userdir$deluser/"
 139                         ssh -p $destport $destuser@$desthost mv "$destdir/$userdir$deluser/" "$destdir/deleted"
 140                         ssh -p $destport -i $destid_file $destuser@$desthost "date +%c%n%s > '$destdir/$userdir$deluser/deleted_on'"
 141                 done
 142         done
 143         rm $tmp1
 144         rm $tmp2
 145 }
 146
 147 function do_rotate() {
 148         [ "$rotate" == "yes" ] || return;
 149         local user=$1
 150         local userdir=${2%/}
 151         local backuproot="$destdir/$userdir/$user"
 152 (
 153         ssh -T -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file <<EOF
 154 ##### BEGIN REMOTE SCRIPT #####
 155         seconds_daily=86400
 156         seconds_weekly=604800
 157         seconds_monthly=2628000
 158         keepdaily=$keepdaily
 159         keepweekly=$keepweekly
 160         keepmonthly=$keepmonthly
 161         now=\`date +%s\`
 162
 163         if [ ! -d "$backuproot" ]; then
 164                 echo "Debug: skipping rotate of $user. $backuproot doesn't exist."
 165                 exit
 166         fi
 167         for rottype in daily weekly monthly; do
 168                 seconds=\$((seconds_\${rottype}))
 169
 170                 dir="$backuproot/\$rottype"
 171                 if [ ! -d \$dir.1 ]; then
 172                         echo "Debug: \$dir.1 does not exist, skipping."
 173                         continue 1
 174                 elif [ ! -f \$dir.1/created ]; then
 175                         echo "Warning: \$dir.1/created does not exist. This backup may be only partially completed. Skipping rotation."
 176                         continue 1
 177                 fi
 178
 179                 # Rotate the current list of backups, if we can.
 180                 oldest=\`find $backuproot -maxdepth 1 -type d -name \$rottype'.*' | @SED@ 's/^.*\.//' | sort -n | tail -1\`
 181                 #echo "Debug: oldest \$oldest"
 182                 [ "\$oldest" == "" ] && oldest=0
 183                 for (( i=\$oldest; i > 0; i-- )); do
 184                         if [ -d \$dir.\$i ]; then
 185                                 if [ -f \$dir.\$i/created ]; then
 186                                         created=\`tail -1 \$dir.\$i/created\`
 187                                 else
 188                                         created=0
 189                                 fi
 190                                 cutoff_time=\$(( now - (seconds*(i-1)) ))
 191                                 if [ ! \$created -gt \$cutoff_time ]; then
 192                                         next=\$(( i + 1 ))
 193                                         if [ ! -d \$dir.\$next ]; then
 194                                                 echo "Debug: \$rottype.\$i --> \$rottype.\$next"
 195                                                 mv \$dir.\$i \$dir.\$next
 196                                                 date +%c%n%s > \$dir.\$next/rotated
 197                                         else
 198                                                 echo "Debug: skipping rotation of \$dir.\$i because \$dir.\$next already exists."
 199                                         fi
 200                                 else
 201                                         echo "Debug: skipping rotation of \$dir.\$i because it was created" \$(( (now-created)/86400)) "days ago ("\$(( (now-cutoff_time)/86400))" needed)."
 202                                 fi
 203                         fi
 204                 done
 205         done
 206
 207         max=\$((keepdaily+1))
 208         if [ \( \$keepweekly -gt 0 -a -d $backuproot/daily.\$max \) -a ! -d $backuproot/weekly.1 ]; then
 209                 echo "Debug: daily.\$max --> weekly.1"
 210                 mv $backuproot/daily.\$max $backuproot/weekly.1
 211                 date +%c%n%s > $backuproot/weekly.1/rotated
 212         fi
 213
 214         max=\$((keepweekly+1))
 215         if [ \( \$keepmonthly -gt 0 -a -d $backuproot/weekly.\$max \) -a ! -d $backuproot/monthly.1 ]; then
 216                 echo "Debug: weekly.\$max --> monthly.1"
 217                 mv $backuproot/weekly.\$max $backuproot/monthly.1
 218                 date +%c%n%s > $backuproot/monthly.1/rotated
 219         fi
 220
 221         for rottype in daily weekly monthly; do
 222                 max=\$((keep\${rottype}+1))
 223                 dir="$backuproot/\$rottype"
 224                 oldest=\`find $backuproot -maxdepth 1 -type d -name \$rottype'.*' | @SED@ 's/^.*\.//' | sort -n | tail -1\`
 225                 [ "\$oldest" == "" ] && oldest=0
 226                 # if we've rotated the last backup off the stack, remove it.
 227                 for (( i=\$oldest; i >= \$max; i-- )); do
 228                         if [ -d \$dir.\$i ]; then
 229                                 if [ -d $backuproot/rotate.tmp ]; then
 230                                         echo "Debug: removing rotate.tmp"
 231                                         rm -rf $backuproot/rotate.tmp
 232                                 fi
 233                                 echo "Debug: moving \$rottype.\$i to rotate.tmp"
 234                                 mv \$dir.\$i $backuproot/rotate.tmp
 235                         fi
 236                 done
 237         done
 238 ####### END REMOTE SCRIPT #######
 239 EOF
 240 ) | (while read a; do passthru $a; done)
 241
 242 }
 243
 244
 245 function setup_remote_dirs() {
 246         local user=$1
 247         local backuptype=$2
 248         local userdir=${3%/}
 249         local dir="$destdir/$userdir/$user/$backuptype"
 250         local tmpdir="$destdir/$userdir/$user/rotate.tmp"
 251 (
 252         ssh -T -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file <<EOF
 253                 if [ ! -d $destdir ]; then
 254                         echo "Fatal: Destination directory $destdir does not exist on host $desthost."
 255                         exit 1
 256                 elif [ -d $dir.1 ]; then
 257                         if [ -f $dir.1/created ]; then
 258                                 echo "Warning: $dir.1 already exists. Overwriting contents."
 259                         else
 260                                 echo "Warning: we seem to be resuming a partially written $dir.1"
 261                         fi
 262                 else
 263                         if [ -d $tmpdir ]; then
 264                                 mv $tmpdir $dir.1
 265                                 if [ \$? == 1 ]; then
 266                                         echo "Fatal: could mv $destdir/rotate.tmp $dir.1 on host $desthost"
 267                                         exit 1
 268                                 fi
 269                         else
 270                                 mkdir --parents $dir.1
 271                                 if [ \$? == 1 ]; then
 272                                         echo "Fatal: could not create directory $dir.1 on host $desthost"
 273                                         exit 1
 274                                 fi
 275                         fi
 276                         if [ -d $dir.2 ]; then
 277                                 echo "Debug: update links $backuptype.2 --> $backuptype.1"
 278                                 cp -alf $dir.2/. $dir.1
 279                                 #if [ \$? == 1 ]; then
 280                                 #       echo "Fatal: could not create hard links to $dir.1 on host $desthost"
 281                                 #       exit 1
 282                                 #fi
 283                         fi
 284                 fi
 285                 [ -f $dir.1/created ] && rm $dir.1/created
 286                 [ -f $dir.1/rotated ] && rm $dir.1/rotated
 287                 exit 0
 288 EOF
 289 ) | (while read a; do passthru $a; done)
 290
 291         if [ $? == 1 ]; then exit; fi
 292 }
 293
 294 function start_mux() {
 295         if [ "$multiconnection" == "yes" ]; then
 296                 debug "Starting dummy ssh connection"
 297                 ssh -p $destport -i $destid_file $destuser@$desthost sleep 1d &
 298         sleep 1
 299         fi
 300 }
 301
 302 function end_mux() {
 303         if [ "$multiconnection" == "yes" ]; then
 304                 debug "Stopping dummy ssh connection"
 305                 ssh -p $destport -i $destid_file $destuser@$desthost pkill sleep
 306         fi
 307 }
 308
 309 ###
 310 ##################################################################
 311
 312 # see if we can login
 313 debug "ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file 'echo -n 1'"
 314 if [ ! $test ]; then
 315         result=`ssh -o PasswordAuthentication=no $desthost -l $destuser -i $destid_file 'echo -n 1' 2>&1`
 316         if [ "$result" != "1" ]; then
 317                 fatal "Can't connect to $desthost as $destuser using $destid_file."
 318         fi
 319 fi
 320
 321 end_mux
 322 start_mux
 323
 324 ## SANITY CHECKS ##
 325 status=`ssh -p $destport -i $destid_file $destuser@$desthost "[ -d \"$destdir\" ] && echo 'ok'"`
 326 if [ "$status" != "ok" ]; then
 327         end_mux
 328         fatal "Destination directory $destdir doesn't exist!"
 329     exit
 330 fi
 331
 332 ### REMOVE OLD MAILDIRS ###
 333
 334 if [ "$remove" == "yes" ]; then
 335         do_remove
 336 fi
 337
 338 ### MAKE BACKUPS ###
 339
 340 if [ "$backup" == "yes" ]; then
 341         if [ $keepdaily -gt 0 ]; then btype=daily
 342         elif [ $keepweekly -gt 0 ]; then btype=weekly
 343         elif [ $keepmonthly -gt 0 ]; then btype=monthly
 344         else fatal "keeping no backups"; fi
 345
 346         if [ "$testuser" != "" ]; then
 347                 cd "$srcdir/${user:0:1}"
 348                 do_rotate $testuser
 349                 setup_remote_dirs $testuser $btype
 350                 do_user $testuser $btype
 351         else
 352                 [ -d "$srcdir" ] || fatal "directory $srcdir not found."
 353                 cd "$srcdir"
 354                 for userdir in `ls -d1 */`; do
 355                    [ -d "$srcdir/$userdir" ] || fatal "directory $srcdir/$userdir not found."
 356                    cd "$srcdir/$userdir"
 357                    debug $userdir
 358                         for user in `ls -1`; do
 359                                 [ "$user" != "" ] || continue
 360                                 debug "$user $userdir"
 361                                 do_rotate $user $userdir
 362                                 setup_remote_dirs $user $btype $userdir
 363                                 do_user $user $btype $userdir
 364                         done
 365                 done
 366         fi
 367 fi
 368
 369 end_mux
 370