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