handlers/maildir

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