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