plugins-scripts/check_log.sh

   1 #!/bin/sh
   2 #
   3 # Log file pattern detector plugin for Nagios
   4 # Written by Ethan Galstad (nagios@nagios.org)
   5 # Last Modified: 07-31-1999
   6 #
   7 # Usage: ./check_log <log_file> <old_log_file> <pattern>
   8 #
   9 # Description:
  10 #
  11 # This plugin will scan a log file (specified by the <log_file> option)
  12 # for a specific pattern (specified by the <pattern> option).  Successive
  13 # calls to the plugin script will only report *new* pattern matches in the
  14 # log file, since an copy of the log file from the previous run is saved
  15 # to <old_log_file>.
  16 #
  17 # Output:
  18 #
  19 # On the first run of the plugin, it will return an OK state with a message
  20 # of "Log check data initialized".  On successive runs, it will return an OK
  21 # state if *no* pattern matches have been found in the *difference* between the
  22 # log file and the older copy of the log file.  If the plugin detects any
  23 # pattern matches in the log diff, it will return a CRITICAL state and print
  24 # out a message is the following format: "(x) last_match", where "x" is the
  25 # total number of pattern matches found in the file and "last_match" is the
  26 # last entry in the log file which matches the pattern.
  27 #
  28 # Notes:
  29 #
  30 # If you use this plugin make sure to keep the following in mind:
  31 #
  32 #    1.  The "max_attempts" value for the service should be 1, as this
  33 #        will prevent Nagios from retrying the service check (the
  34 #        next time the check is run it will not produce the same results).
  35 #
  36 #    2.  The "notify_recovery" value for the service should be 0, so that
  37 #        Nagios does not notify you of "recoveries" for the check.  Since
  38 #        pattern matches in the log file will only be reported once and not
  39 #        the next time, there will always be "recoveries" for the service, even
  40 #        though recoveries really don't apply to this type of check.
  41 #
  42 #    3.  You *must* supply a different <old_file_log> for each service that
  43 #        you define to use this plugin script - even if the different services
  44 #        check the same <log_file> for pattern matches.  This is necessary
  45 #        because of the way the script operates.
  46 #
  47 # Examples:
  48 #
  49 # Check for login failures in the syslog...
  50 #
  51 #   check_log /var/log/messages ./check_log.badlogins.old "LOGIN FAILURE"
  52 #
  53 # Check for port scan alerts generated by Psionic's PortSentry software...
  54 #
  55 #   check_log /var/log/message ./check_log.portscan.old "attackalert"
  56 #
  57
  58 # Paths to commands used in this script.  These
  59 # may have to be modified to match your system setup.
  60 # TV: removed PATH restriction. Need to think more about what this means overall
  61 #PATH=""
  62
  63 ECHO="/bin/echo"
  64 GREP="/bin/egrep"
  65 DIFF="/bin/diff"
  66 TAIL="/bin/tail"
  67 CAT="/bin/cat"
  68 RM="/bin/rm"
  69 CHMOD="/bin/chmod"
  70 TOUCH="/bin/touch"
  71
  72 PROGNAME=`/bin/basename $0`
  73 PROGPATH=`echo $0 | sed -e 's,[\\/][^\\/][^\\/]*$,,'`
  74 REVISION=`echo '$Revision$' | sed -e 's/[^0-9.]//g'`
  75
  76 . $PROGPATH/utils.sh
  77
  78 print_usage() {
  79     echo "Usage: $PROGNAME -F logfile -O oldlog -q query"
  80     echo "Usage: $PROGNAME --help"
  81     echo "Usage: $PROGNAME --version"
  82 }
  83
  84 print_help() {
  85     print_revision $PROGNAME $REVISION
  86     echo ""
  87     print_usage
  88     echo ""
  89     echo "Log file pattern detector plugin for Nagios"
  90     echo ""
  91     support
  92 }
  93
  94 # Make sure the correct number of command line
  95 # arguments have been supplied
  96
  97 if [ $# -lt 1 ]; then
  98     print_usage
  99     exit $STATE_UNKNOWN
 100 fi
 101
 102 # Grab the command line arguments
 103
 104 #logfile=$1
 105 #oldlog=$2
 106 #query=$3
 107 exitstatus=$STATE_WARNING #default
 108 while test -n "$1"; do
 109     case "$1" in
 110         --help)
 111             print_help
 112             exit $STATE_OK
 113             ;;
 114         -h)
 115             print_help
 116             exit $STATE_OK
 117             ;;
 118         --version)
 119             print_revision $PROGNAME $VERSION
 120             exit $STATE_OK
 121             ;;
 122         -V)
 123             print_revision $PROGNAME $VERSION
 124             exit $STATE_OK
 125             ;;
 126         --filename)
 127             logfile=$2
 128             shift
 129             ;;
 130         -F)
 131             logfile=$2
 132             shift
 133             ;;
 134         --oldlog)
 135             oldlog=$2
 136             shift
 137             ;;
 138         -O)
 139             oldlog=$2
 140             shift
 141             ;;
 142         --query)
 143             query=$2
 144             shift
 145             ;;
 146         -q)
 147             query=$2
 148             shift
 149             ;;
 150         -x)
 151             exitstatus=$2
 152             shift
 153             ;;
 154         --exitstatus)
 155             exitstatus=$2
 156             shift
 157             ;;
 158         *)
 159             echo "Unknown argument: $1"
 160             print_usage
 161             exit $STATE_UNKNOWN
 162             ;;
 163     esac
 164     shift
 165 done
 166
 167 # If the source log file doesn't exist, exit
 168
 169 if [ ! -e $logfile ]; then
 170     $ECHO "Log check error: Log file $logfile does not exist!\n"
 171     exit $STATE_UNKNOWN
 172 elif [ ! -r $logfile ] ; then
 173     $ECHO "Log check error: Log file $logfile is not readable!\n"
 174     exit $STATE_UNKNOWN
 175 fi
 176
 177 # If the old log file doesn't exist, this must be the first time
 178 # we're running this test, so copy the original log file over to
 179 # the old diff file and exit
 180
 181 if [ ! -e $oldlog ]; then
 182     $CAT $logfile > $oldlog
 183     $ECHO "Log check data initialized...\n"
 184     exit $STATE_OK
 185 fi
 186
 187 # The old log file exists, so compare it to the original log now
 188
 189 # The temporary file that the script should use while
 190 # processing the log file.
 191 if [ -x /bin/mktemp ]; then
 192     tempdiff=`/bin/mktemp /tmp/check_log.XXXXXXXXXX`
 193 else
 194     tempdiff=`/bin/date '+%H%M%S'`
 195     tempdiff="/tmp/check_log.${tempdiff}"
 196     $TOUCH $tempdiff
 197     $CHMOD 600 $tempdiff
 198 fi
 199
 200 $DIFF $logfile $oldlog | $GREP -v "^>" > $tempdiff
 201
 202 # Count the number of matching log entries we have
 203 count=`$GREP -c "$query" $tempdiff`
 204
 205 # Get the last matching entry in the diff file
 206 lastentry=`$GREP "$query" $tempdiff | $TAIL -1`
 207
 208 $RM -f $tempdiff
 209 $CAT $logfile > $oldlog
 210
 211 if [ "$count" = "0" ]; then # no matches, exit with no error
 212     $ECHO "Log check ok - 0 pattern matches found\n"
 213     exitstatus=$STATE_OK
 214 else # Print total matche count and the last entry we found
 215     $ECHO "($count) $lastentry"
 216     exitstatus=$STATE_CRITICAL
 217 fi
 218
 219 exit $exitstatus