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 #
58 # Paths to commands used in this script. These
59 # may have to be modified to match your system setup.
61 PATH=""
63 ECHO="/bin/echo"
64 GREP="/bin/grep"
65 DIFF="/bin/diff"
66 TAIL="/bin/tail"
67 CAT="/bin/cat"
68 RM="/bin/rm"
70 PROGNAME=`/bin/basename $0`
71 PROGPATH=`echo $0 | /bin/sed -e 's,[\\/][^\\/][^\\/]*$,,'`
72 REVISION=`echo '$Revision$' | /bin/sed -e 's/[^0-9.]//g'`
74 . $PROGPATH/utils.sh
76 print_usage() {
77 echo "Usage: $PROGNAME -F logfile -O oldlog -q query"
78 echo "Usage: $PROGNAME --help"
79 echo "Usage: $PROGNAME --version"
80 }
82 print_help() {
83 print_revision $PROGNAME $REVISION
84 echo ""
85 print_usage
86 echo ""
87 echo "Log file pattern detector plugin for Nagios"
88 echo ""
89 support
90 }
92 # Make sure the correct number of command line
93 # arguments have been supplied
95 if [ $# -lt 1 ]; then
96 print_usage
97 exit $STATE_UNKNOWN
98 fi
100 # Grab the command line arguments
102 #logfile=$1
103 #oldlog=$2
104 #query=$3
105 exitstatus=$STATE_WARNING #default
106 while test -n "$1"; do
107 case "$1" in
108 --help)
109 print_help
110 exit $STATE_OK
111 ;;
112 -h)
113 print_help
114 exit $STATE_OK
115 ;;
116 --version)
117 print_revision $PROGNAME $VERSION
118 exit $STATE_OK
119 ;;
120 -V)
121 print_revision $PROGNAME $VERSION
122 exit $STATE_OK
123 ;;
124 --filename)
125 logfile=$2
126 shift
127 ;;
128 -F)
129 logfile=$2
130 shift
131 ;;
132 --oldlog)
133 oldlog=$2
134 shift
135 ;;
136 -O)
137 oldlog=$2
138 shift
139 ;;
140 --query)
141 query=$2
142 shift
143 ;;
144 -q)
145 query=$2
146 shift
147 ;;
148 -x)
149 exitstatus=$2
150 shift
151 ;;
152 --exitstatus)
153 exitstatus=$2
154 shift
155 ;;
156 *)
157 echo "Unknown argument: $1"
158 print_usage
159 exit $STATE_UNKNOWN
160 ;;
161 esac
162 shift
163 done
165 # If the source log file doesn't exist, exit
167 if [ ! -e $logfile ]; then
168 $ECHO "Log check error: Log file $logfile does not exist!\n"
169 exit $STATE_UNKNOWN
170 fi
172 # If the old log file doesn't exist, this must be the first time
173 # we're running this test, so copy the original log file over to
174 # the old diff file and exit
176 if [ ! -e $oldlog ]; then
177 $CAT $logfile > $oldlog
178 $ECHO "Log check data initialized...\n"
179 exit $STATE_OK
180 fi
182 # The old log file exists, so compare it to the original log now
184 # The temporary file that the script should use while
185 # processing the log file.
186 if [ -x /bin/mktemp ]; then
187 tempdiff=`/bin/mktemp /tmp/check_log.XXXXXXXXXX`
188 else
189 tempdiff=`/bin/date '+%H%M%S'`
190 tempdiff="/tmp/check_log.${tempdiff}"
191 /bin/touch $tempdiff
192 chmod 600 $tempdiff
193 fi
195 $DIFF $logfile $oldlog > $tempdiff
197 # Count the number of matching log entries we have
198 count=`$GREP -c "$query" $tempdiff`
200 # Get the last matching entry in the diff file
201 lastentry=`$GREP "$query" $tempdiff | $TAIL --lines=1`
203 $RM -f $tempdiff
204 $CAT $logfile > $oldlog
206 if [ "$count" = "0" ]; then # no matches, exit with no error
207 $ECHO "Log check ok - 0 pattern matches found\n"
208 exitstatus=$STATE_OK
209 else # Print total matche count and the last entry we found
210 $ECHO "($count) $lastentry"
211 exitstatus=$STATE_CRITICAL
212 fi
214 exit $exitstatus