handlers/maildir

   1 ###############################################################
   2 #
   3 #  This handler slowly creates a backup of each user's maildir
   4 #  to a remote server. It is designed to be run with low overhead
   5 #  in terms of cpu and bandwidth so it runs pretty slow.
   6 #
   7 #  if destdir is /backup/maildir/, then it will contain the files
   8 #    daily.1
   9 #    daily.2
  10 #    daily.3
  11 #    weekly.1
  12 #    weekly.2
  13 #    monthly.1
  14 #  if keepdaily is 3, keepweekly is 2, and keepmonthly is 1.
  15 #
  16 #  The basic algorithm is to rsync each maildir individually,
  17 #  and to use hard links for retaining historical data.
  18 #
  19 #  We rsync each maildir individually because it becomes very
  20 #  unweldy to start a single rsync of many hundreds of thousands
  21 #  of files.
  22 #
  23 #  For the backup rotation to work, destuser must be able to run
  24 #  arbitrary bash commands on the desthost.
  25 #
  26 ##############################################################
  27
  28 getconf rotate yes
  29 getconf remove yes
  30
  31 getconf loadlimit 5
  32 getconf speedlimit 0
  33 getconf keepdaily 5
  34 getconf keepweekly 3
  35 getconf keepmonthly 1
  36
  37 getconf srcdir /var/maildir
  38 getconf destdir
  39 getconf desthost
  40 getconf destport 22
  41 getconf destuser
  42
  43 failedcount=0
  44
  45 # strip trailing /
  46 destdir=${destdir%/}
  47 srcdir=${srcdir%/}
  48
  49 # used for testing
  50 #getconf letter
  51 #getconf testuser elijah
  52 getconf backup yes
  53 #letters=e
  54 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"
  55
  56 [ -d $srcdir ] || fatal "source directory $srcdir doesn't exist"
  57
  58 [ ! $test ] || testflags="--dry-run -v"
  59 rsyncflags="$testflags -e 'ssh -p $destport' -r -v --ignore-existing --delete --size-only --bwlimit=$speedlimit"
  60 excludes="--exclude '.Trash/\*' --exclude '.Mistakes/\*' --exclude '.Spam/\*'"
  61
  62 # see if we can login
  63 debug "ssh -o PasswordAuthentication=no $desthost -l $destuser 'echo -n 1'"
  64 if [ ! $test ]; then
  65         result=`ssh -o PasswordAuthentication=no $desthost -l $destuser 'echo -n 1' 2>&1`
  66         if [ "$result" != "1" ]; then
  67                 fatal "Can't connect to $desthost as $destuser."
  68         fi
  69 fi
  70
  71 ##################################################################
  72 ### FUNCTIONS
  73
  74 function do_user() {
  75         local user=$1
  76         local destdir=$2
  77         local letter=${user:0:1}
  78         local dir="$srcdir/$letter/$user"
  79         [ -d $dir ] || fatal "maildir $dir not found".
  80
  81 #       while true; do
  82 #               load=`uptime | sed 's/^.*load average: \\([^,]*\\).*$/\\1/'`
  83 #               over=`expr $load \> $loadlimit`
  84 #               if [ $over == 1 ]; then
  85 #                       info "load $load, sleeping..."
  86 #                       sleep 600
  87 #               else
  88 #                       break
  89 #               fi
  90 #       done
  91
  92         cmd="$RSYNC $rsyncflags $excludes $dir $destuser@$desthost:$destdir/$letter"
  93         ret=`rsync -e "ssh -p $destport" -r \
  94 --links --ignore-existing --delete --size-only --bwlimit=$speedlimit \
  95 --exclude '.Trash/*' --exclude '.Mistakes/*' --exclude '.Spam/*' \
  96 $dir $destuser@$desthost:$destdir/$letter \
  97 2>&1`
  98         ret=$?
  99         # ignore 0 (success) and 24 (file vanished before it could be copied)
 100         if [ $ret != 0 -a $ret != 24 ]; then
 101                 warning "rsync $user failed"
 102                 warning "  returned: $ret"
 103                 let "failedcount = failedcount + 1"
 104                 if [ $failedcount -gt 100 ]; then
 105                         fatal "100 rsync errors -- something is not working right. bailing out."
 106                 fi
 107         fi
 108 }
 109
 110 # remove any maildirs from backup which might have been deleted
 111 # and add new ones which have just been created.
 112
 113 function do_remove() {
 114         local tmp1=`maketemp maildir-tmp-file`
 115         local tmp2=`maketemp maildir-tmp-file`
 116
 117         for i in a b c d e f g h i j k l m n o p q r s t u v w x y z; do
 118                 ls -1 "$srcdir/$i" | sort > $tmp1
 119                 ssh -p $destport $desthost ls -1 '$destdir/maildir/$i' | sort > $tmp2
 120                 for deluser in `join -v 2 $tmp1 $tmp2`; do
 121                         cmd="ssh -p $destport $desthost rm -vr '$destdir/maildir/$i/$deluser/'"
 122                         debug $cmd
 123                 done
 124         done
 125         rm $tmp1
 126         rm $tmp2
 127 }
 128
 129 function do_rotate() {
 130         backuproot=$destdir
 131
 132 (
 133         debug Connecting to $desthost
 134         ssh -T -o PasswordAuthentication=no $desthost -l $destuser <<EOF
 135 ##### BEGIN REMOTE SCRIPT #####
 136         seconds_daily=86400
 137         seconds_weekly=604800
 138         seconds_monthly=2628000
 139         keepdaily=$keepdaily
 140         keepweekly=$keepweekly
 141         keepmonthly=$keepmonthly
 142         now=\`date +%s\`
 143
 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 "Info: \$dir.1 does not exist. This backup is missing, so we are skipping the rotation."
 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: mv \$dir.\$i \$dir.\$next"
 172                                                 mv \$dir.\$i \$dir.\$next
 173                                                 date +%c%n%s > \$dir.\$next/rotated
 174                                         else
 175                                                 echo "Info: skipping rotation of \$dir.\$i because \$dir.\$next already exists."
 176                                         fi
 177                                 else
 178                                         echo "Info: 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 mv $backuproot/daily.\$max $backuproot/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 mv $backuproot/weekly.\$max $backuproot/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 "Info: removing $backuproot/rotate.tmp"
 208                                         rm -rf $backuproot/rotate.tmp
 209                                 fi
 210                                 echo "Info: moving \$dir.\$i to $backuproot/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 backuptype=$1
 224         local dir="$destdir/$backuptype"
 225
 226 (
 227         ssh -T -o PasswordAuthentication=no $desthost -l $destuser <<EOF
 228                 if [ ! -d $destdir ]; then
 229                         echo "Fatal: Destination directory $destdir does not exist on host $desthost."
 230                         exit 1
 231                 elif [ -d $dir.1 ]; then
 232                         if [ -f $dir.1/created ]; then
 233                                 echo "Warning: $dir.1 already exists. Overwriting contents."
 234                         else
 235                                 echo "Warning: we seem to be resuming a partially written $dir.1"
 236                         fi
 237                 else
 238                         if [ -d $destdir/rotate.tmp ]; then
 239                                 mv $destdir/rotate.tmp $dir.1
 240                                 if [ \$? == 1 ]; then
 241                                         echo "Fatal: could mv $destdir/rotate.tmp $dir.1 on host $desthost"
 242                                         exit 1
 243                                 fi
 244                         else
 245                                 mkdir $dir.1
 246                                 if [ \$? == 1 ]; then
 247                                         echo "Fatal: could not create directory $dir.1 on host $desthost"
 248                                         exit 1
 249                                 fi
 250                                 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 y x z; do
 251                                         mkdir $dir.1/\$i
 252                                 done
 253                         fi
 254                         if [ -d $destdir/$backuptype.2 ]; then
 255                                 echo "Info: updating hard links to $dir.1. This may take a while."
 256                                 cp -alf $destdir/$backuptype.2/. $dir.1
 257                                 #if [ \$? == 1 ]; then
 258                                 #       echo "Fatal: could not create hard links to $dir.1 on host $desthost"
 259                                 #       exit 1
 260                                 #fi
 261                         fi
 262                 fi
 263                 [ -f $dir.1/created ] && rm $dir.1/created
 264                 [ -f $dir.1/rotated ] && rm $dir.1/rotated
 265                 exit 0
 266 EOF
 267 ) | (while read a; do passthru $a; done)
 268
 269         if [ $? == 1 ]; then exit; fi
 270 }
 271
 272 ###
 273 ##################################################################
 274
 275 ### ROTATE BACKUPS ###
 276
 277 if [ "$rotate" == "yes" ]; then
 278         do_rotate
 279 fi
 280
 281 ### REMOVE OLD MAILDIRS ###
 282
 283 if [ "$remove" == "yes" ]; then
 284         debug remove
 285 fi
 286
 287 ### MAKE BACKUPS ###
 288
 289 if [ "$backup" == "yes" ]; then
 290         if [ $keepdaily -gt 0 ]; then btype=daily
 291         elif [ $keepweekly -gt 0 ]; then btype=weekly
 292         elif [ $keepmonthly -gt 0 ]; then btype=monthly
 293         else fatal "keeping no backups"; fi
 294
 295         setup_remote_dirs $btype
 296
 297         for i in $letters; do
 298                 [ -d "$srcdir/$i" ] || fatal "directory $srcdir/$i not found."
 299                 cd "$srcdir/$i"
 300                 debug $i
 301                 for user in `ls -1`; do
 302                         if [ "$testuser" != "" -a "$testuser" != "$user" ]; then continue; fi
 303                         do_user $user $destdir/$btype.1
 304                 done
 305         done
 306
 307         ssh -o PasswordAuthentication=no $desthost -l $destuser "date +%c%n%s > $destdir/$btype.1/created"
 308 fi