X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=backup.sh;h=4d8565bea85cefd208d9338f9ffa59feadbdef14;hb=113951598d3d236ea9f3a6c41f08bb713ffd700e;hp=cf2e24b31205389185aaf20edc6d11a15d29abd0;hpb=80b6956d5393876a935dafcd3bbcac655f63d0d3;p=backup.sh

diff --git a/backup.sh b/backup.sh
index cf2e24b..4d8565b 100755
--- a/backup.sh
+++ b/backup.sh
@@ -1,12 +1,52 @@
 #!/bin/sh
-
-# Locking
+# backup.sh
+# 
+# Backup up Unix-like computers
+# 
+# itk@samfundet.no
+#
+# This script was first checked into RCS in 2000, and has since backed up a few
+# servers almost every day, whenever not broken.
+# 
+# It's a bit peculiar, but quite effective. The following is worth keeping in
+# mind when hacking:
+#
+# KISS. And by that I mean really simple. Only regular Unix commands, please
+# (but GNU extensions are used).
+#
+# Because of the way we run this script from cron, informational logging goes
+# to stderr and warnings and errors to stdout. This way, we get mail whenever
+# stuff fails, and other output is redirected to the log file.
+# 
+# The computers are backed up in parallell (but the filesystems on each
+# computer in serial). This is implemented highly simplistic, with forking
+# subshells. The script has no concept about threads, and stuff might go wrong,
+# which usually requires manual cleanups.
+#
+# The script is halfway Norwegian and halfway English. Newer modifications are
+# in English, we should probably stick to that.
+
+# TODO(sesse, 2007-12-16): 
+#  * Sjekk hvorfor .idx-filene til UD er blitt 0 for siste fullbackuper
+#  * Rydde uleselig kode fra linje 211 og litt nedover
+
+# Configuration
 LOCKFILE=/home/backup/backuprun.lockfile
+confdir=/home/backup/conf/           # Configuration files
+storagedir=/backup                   # Where we keep backups
+maksantallfulle=3                    # Number of full backups
+dagermellomfulle=30                  # Days between full backups
+DATE=`date "+%Y%m%d%H%M"`            #format: touch
+DATEs=`date "+%Y-%m-%d %H:%M"`       #format: tar
+
+# Exclude-pattern
+exclude=$confdir/exclude
+[ ! -f $exclude ] && printf "tmp\ncore\n" > $exclude
 
 # Initially, we consider everything to be just fine.
 R=0
 
-# Die gracefully (ie. remove lockfile)
+# Die more or less gracefully (at least notify user)
 die() {
 	echo `date`": Something nasty happened, and since I fork a lot:"
         echo `date`": I CANNOT CLEAN UP THE MESS MYSELF."
@@ -20,20 +60,11 @@ trap die SIGINT SIGTERM
 # Don't start if we're already running
 if [ -e $LOCKFILE ]; then
 	echo `date`": $LOCKFILE exists, exiting."
+	echo `date`": $LOCKFILE exists, exiting." >&2
 	exit 1
 fi;
 touch $LOCKFILE
 
-#dirs
-confdir=/home/backup/conf/           #configuration files
-storagedir=/backup                   #mountpoint of huge disc
-###
-
-#exclude-pattern
-exclude=$confdir/exclude
-[ ! -f $exclude ] && printf "tmp\ncore\n" > $exclude
-###
-
 #syntax of remotestat:
 #hostname:/directory/
 remotestatf=$confdir/remotestat
@@ -43,7 +74,6 @@ remotestatf=$confdir/remotestat
 PATH=/local/bin:$PATH:/store/bin
 export PATH
 
-#start the logfile
 echo `date`": Backup run starting" >&2
 
 umask 027
@@ -58,16 +88,6 @@ if [ $1 ] ; then
   unixcomputers=$1
 fi;
 
-#disse bør kunne varieres fra fs til fs?
-maksantallfulle=3          #hvor mange fulle vi tar vare på
-dagermellomfulle=30        #antall dager før det er på tide med ny full
-logw=40
-###
-
-#lager datovariabeler
-DATE=`date "+%Y%m%d%H%M"`            #format: touch
-DATEs=`date "+%Y-%m-%d %H:%M"`       #format: tar
-###
 
 #selve backupen
 # krever at noen variabler er satt
@@ -76,7 +96,7 @@ backup()
 {
 
  echo -n `date` >&2
- printf " $computer: %-${logw}s %s\n" "$computer:$filesystem" "$backuplevel backup" >&2
+ printf " $computer: $computer:$filesystem $backuplevel backup" >&2
 
  if [ "$backuplevel" = "daglig" ] || [ "$backuplevel" = "incremental" ]
  then
@@ -94,42 +114,43 @@ backup()
    tar=tar
  fi
 
- #expand the exclude-path for use with tar
+ # expand the exclude-path for use with tar
  exf=`ssh root@$computer "ls ~/.backup/exclude"`
 
- #We try to run tar on the remote computer
+ # We try to run tar on the remote computer
  #    z gzip it
  #    c create archive
  #    C change to directory first
- #    - output to stdout (we pipe to gzip, then to dd)
  #    . where to start taring (see C)
  #    $lastcmd only files newer than this
+ #    --one-file-system don't traverse file systems
  #    --exclude-from file to get exclusion pattern from
- #    pipe to gzip, which in turn pipes over the ssh-stream
- #    ..to dd, to output to a file. We surpress messages from dd.
- #    And at last, redirect stderr to stdout, to get output logged.
+ #    Pipe the stuff over ssh to ourselves, run pee to cat the contents to a
+ #    file and build a file list, respectivly.  
  TARFILE=$DATE.tmp
  TARCMD="ssh root@$computer \"$tar --one-file-system -zcf - -C $filesystem . $lastcmd \
-	--exclude-from=$exf\" > $TARFILE"
+	--exclude-from=$exf\" | pee \"cat > $TARFILE\" \"tar tzvf -\""
  echo `date`" $computer: Running $TARCMD" >&2
- eval $TARCMD;
+ eval $TARCMD > $DATE.idx
+
  if [ -s $TARFILE ]; then
+  # File is >0 in size, we assume it worked.
+
+  # Move tar file in place
   mv $TARFILE $DATE.tgz
-  #make a filelist.
-  #update the datefile if the filelist is ok.
-  tar tvfz $DATE.tgz > $DATE.idx 2>&1 &&
-    echo $DATEs > ../.date            &&
-    touch -t $DATE ../.date
 
-  #make a sortet filelist
-  grep -v ^d $DATE.idx | sort -n -r +2 > $DATE.sdx
+  # Update timestamp
+  echo $DATEs > ../.date && touch -t $DATE ../.date
+
+  # Make a sorted filelist
+  grep -v ^d $DATE.idx | sort -n -r -k 2 > $DATE.sdx
 
-  #fix perm
+  # Fix permissions
   chmod 600 *tgz                      #only for us
   chmod 644 *sdx *idx 2>/dev/null     #everyone can read
 
  else
-  #it did not work
+  # Something wrong happened.
   rm $TARFILE
   echo `date`" $computer: $TARFILE empty. $backuplevel backup of $computer:$filesystem failed and deleted"
 
@@ -139,10 +160,18 @@ backup()
 
 }
 
-#Løper gjennom listen av unixmaskiner som vi skal ta backup av
 for computer in $unixcomputers
 do
 ( 
+ # Check that the target filesystem is mounted (actually check that it's not
+ # the root filesystem)
+ rootfilesystem=`df -P /`
+ targetfilesystem=`df -P "$storagedir/$computer"`
+ if [ "$rootfilesystem" == "$targetfilesystem" ]; then
+ 	echo `date`" $computer: Target filesystem ($storagedir/$computer) was mounted on /. Aborting"
+	continue
+ fi
+
  echo `date`" $computer: Backing up $computer" >&2
 
  # Try to SSH to the computer without entering a password.
@@ -155,33 +184,30 @@ do
   continue;
  fi
  
- #tømmer variabelen for sikkerhets skyld
  filesystems=""
 
- #Sjekker nest siste felt i fstab. Om det er 0 tar vi ikke backup
+ # Check dump bit in fstab
  filesystems=`ssh -n root@$computer "cat /etc/fstab" \
   | grep -v nfs \
   | grep -v "^#" \
   | grep -v "^$" \
   | awk '{ if ( $(NF-1) != "0" ) print $2}' `
 
- #clean up our dir at this client
+ # Clean up our dir at this client
  if ! ssh root@$computer "rm -r ~/.backup ; mkdir -m 700 ~/.backup"; then
   echo `date`" $computer: Could not create backup staging area at $computer:~/.backup - skipping backup of $computer"
-  # We don't want to return 0
   R=1
   continue;
  fi
 
- #try to copy $exclude to $computer
+ # Try to copy $exclude to $computer
  if ! scp $exclude root@$computer:~/.backup/exclude > /dev/null; then
   echo `date`" $computer: Could not copy exclude.txt to $computer - skipping backup of $computer"
-  # We don't want to return 0
   R=1
   continue;
  fi
 
- #try to copy preeexec and postexec if they exist
+ # Try to copy preeexec and postexec if they exist
 # TODO: Gah, clean this mess!
  [ -f $confdir/preexec.$computer ] && (
     scp $confdir/preexec.$computer  root@$computer:~/.backup/preexec >&2 ||
@@ -198,7 +224,7 @@ do
      )
     )
 
- #try to run preexec if it exist
+ # Try to run preexec if it exist
  if ! ssh root@$computer "[ ! -f ~/.backup/preexec ] || /bin/bash -x ~/.backup/preexec" >&2; then
  	echo `date`" $computer: Could not run $computer:~/.backup/preexec - skipping backup of $computer"
 	R=1
@@ -208,69 +234,68 @@ do
 
  for filesystem in $filesystems
  do
-  #lager en variant uten tegnet "/" eller $ (gjelder NT)
+  # Remove / and $ (for Windows) for path names
   sfilesystem=`echo $filesystem | tr '\/\$' '__'`
 
-  #lager det som trengs av kataloger
+  # Prepare storage area
   mkdir -m 755 -p $storagedir/$computer/$sfilesystem/{full,daglig} 2>/dev/null
-
   echo $filesystem > ${storagedir}/${computer}/.${sfilesystem}.name 
   chmod 644 ${storagedir}/${computer}/.${sfilesystem}.name
 
-  #set default backuplevel
+  # Default backuplevel
   backuplevel=daglig
 
   if [ ! -f $storagedir/$computer/$sfilesystem/.date ]
   then
-   #take the first full backup of this filesystem on this computer
+   # Take the first full backup of this filesystem on this computer
    backuplevel=full
    echo $DATEs > $storagedir/$computer/$sfilesystem/.date
   fi
 
-  #sjekker om det er på tide med en full
+  # Check if we want a full backup
   if [ -z "`find $storagedir/$computer/$sfilesystem/full/ -name \*tgz -mtime -$dagermellomfulle`" ]; then
    backuplevel=full
   fi
  
-  #gå ned i rett katalog, eller dø 
-  # TODO bør sende mail om dette skjer!
+  # We want to be here
   cd $storagedir/$computer/$sfilesystem/$backuplevel || die
 
-  #perform the actual backup
+  # Perform the actual backup
   backup
 
-  # Sjekk om det skal være et annet antall fulle backuper av en boks
+  # Check if this box has a custom number of full backups
   if [ -f $confdir/maksfulle.$computer ] ; then
     mf=$((`cat $confdir/maksfulle.$computer`+1))
   else
     mf=$(($maksantallfulle+1))
   fi
 
-  #delete complete backups
-  for full in `ls -1t $storagedir/$computer/$sfilesystem/full/*tgz | tail +$mf`
+  # Delete old full backups
+  for full in `ls -1t $storagedir/$computer/$sfilesystem/full/*tgz | tail -n +$mf`
   do
    prefix=`echo $full | sed "s/\.[^.]*$//"`
-   echo `date`": $computer:$filesystem sletter full $prefix (for mange)" >&2
+   echo `date`": $computer:$filesystem Deleting full backup $prefix" >&2
    rm $prefix*
   done
 
-  #delete incremental backups older than the oldest complete backup
+  # Delete incremental backups older than the oldest full backup
   oldf=`ls -t1 $storagedir/$computer/$sfilesystem/full/*tgz | tail -1`
   find \
      $storagedir/$computer/$sfilesystem/daglig \
      -type f \
      \! -newer $oldf \
-     -exec rm {} \;
+     -printf "`date`: $computer: Deleting old incremental backup: %p\n" \
+     -exec rm {} \; >&2
  done
 
- #try to run postexec if it exist
+ # Try to run postexec if it exist
  if ! ssh root@$computer "[ ! -f ~/.backup/postexec ] || /bin/bash -x ~/.backup/postexec" >&2; then
  	echo `date`" $computer: Could not run $computer:~/.backup/postexec"
 	R=1
  fi
 
-)  
-done &
+) &
+done
 
 wait
 
@@ -279,7 +304,7 @@ rm $LOCKFILE
 
 # Did anything go wrong?
 # (IMPORTANT NOTE: The R-business does not work as expected, since this script
-# forks itself.
+# forks itself).
 if [ $R != 0 ]; then
 	echo `date`": Backup run ended with errors, check logs."
 	exit 1