From c09c239625cfb8364d0e06052ba7b0d7ebe9d861 Mon Sep 17 00:00:00 2001
From: "Hahn Axel (hahn)" <axel.hahn@iml.unibe.ch>
Date: Fri, 12 Nov 2021 13:48:04 +0100
Subject: [PATCH] update dns response time check
---
check_dns_responsetime | 82 ++++++++++++++++++++++++++----------------
1 file changed, 52 insertions(+), 30 deletions(-)
diff --git a/check_dns_responsetime b/check_dns_responsetime
index 10cb136..deee32e 100755
--- a/check_dns_responsetime
+++ b/check_dns_responsetime
@@ -7,14 +7,35 @@
#
# ----------------------------------------------------------------------
# 2020-06-17 v1.0 <axel.hahn@iml.unibe.ch>
+# 2021-11-12 v1.1 <axel.hahn@iml.unibe.ch> check fqd instead of fixed value
+# test tcp 53 first
+# check result depends on 1st nameserver only
# ======================================================================
. `dirname $0`/inc_pluginfunctions
tmpfile=/tmp/check_netstat_out_$$
infofile=/tmp/check_netstat_out_2_$$
-myHost=www.unibe.ch
+myHost=$( hostname -f )
+echo $myHost | cut -f 3- -d "." | grep "\." >/dev/null
+if [ $? -ne 0 ]; then
+ ph.setStatus unknown
+ ph.status "DNS check for [$myHost] - SKIP: hostname -f returned a FQDN with less than 2 dots"
+ ph.exit
+fi
+
+# set default / override from command line params
+typeset -i iWarnLimit=` ph.getValueWithParam 300 w "$@"`
+typeset -i iCriticalLimit=` ph.getValueWithParam 1000 c "$@"`
+
+rm -f $tmpfile $infofile 2>/dev/null
+
+typeset -i iMax=0
+typeset -i iTime=0
+
+typeset -i iCounter=0
+typeset -i iNotReachable=0
# ----------------------------------------------------------------------
# MAIN
@@ -33,44 +54,45 @@ if [ "$1" = "-h" ]; then
exit 0
fi
-# set default / override from command line params
-typeset -i iWarnLimit=` ph.getValueWithParam 300 w "$@"`
-typeset -i iCriticalLimit=` ph.getValueWithParam 1000 c "$@"`
-
-rm -f $tmpfile $infofile 2>/dev/null
-
-typeset -i iMax=0
-typeset -i iTime=0
-
for mydns in `grep ^nameserver /etc/resolv.conf | awk '{ print $2 } ' `
do
+ iCounter=$iCounter+1
typeset -i iSrvMax=0
echo "" >>$infofile
- # echo "---------- `date` $mydns " >>$infofile
+ echo "---------- $iCounter - $mydns " >>$infofile
# todo loop
- for i in `seq 5`
- do
- # echo "" >>$infofile
- # echo "---------- `date` -- $mydns - $i" >>$infofile
- (time nslookup ${myHost} $mydns) >$tmpfile 2>&1
-
- iTime=`cat $tmpfile | grep "^real.*m.*\..*s" | cut -f 2 -d "m" | sed "s#[\.s]##g" | sed "s#^0*##g" `
- echo "$mydns #$i >>> $iTime ms" >>$infofile
- test $iTime -ge $iWarnLimit && cat $tmpfile >> $infofile
-
- test $iTime -gt $iSrvMax && iSrvMax=$iTime
- done
-
- label=`echo $mydns | sed "s#\.#-#g" `
- ph.perfadd "response-$label" "${iSrvMax}"
- test $iSrvMax -gt $iMax && iMax=$iSrvMax
+ >/dev/tcp/${mydns}/53 >>$infofile 2>&1
+ if [ $? -ne 0 ]; then
+ iNotReachable=$iNotReachable+1
+ test $iCounter -eq 1 && ph.setStatus critical
+ echo "ERROR: ${mydns} is not reachable on tcp 53" >>$infofile
+ else
+ for i in `seq 5`
+ do
+ (time nslookup ${myHost} $mydns) >$tmpfile 2>&1
+
+ iTime=`cat $tmpfile | grep "^real.*m.*\..*s" | cut -f 2 -d "m" | sed "s#[\.s]##g" | sed "s#^0*##g" `
+ echo "$mydns #$i >>> $iTime ms" >>$infofile
+ test $iTime -ge $iWarnLimit && cat $tmpfile | grep -vE "^(real|user|sys)" >> $infofile
+ test $iTime -gt $iSrvMax && iSrvMax=$iTime
+
+ done
+ echo "max: $iSrvMax ms" >>$infofile
+
+ # --- set status
+ test $iCounter -eq 1 && ph.setStatusByLimit $iSrvMax $iWarnLimit $iCriticalLimit
+
+ label=`echo $mydns | sed "s#\.#-#g" `
+ ph.perfadd "response-$label" "${iSrvMax}"
+ test $iSrvMax -gt $iMax && iMax=$iSrvMax
+ fi
+ test $iCounter -eq 1 && (echo " ^"; echo " |"; echo " +--- 1st nameserver is relevant for total status of the check. Limits are warning=$iWarnLimit and critical=$iCriticalLimit") >>$infofile
+ echo "" >>$infofile
done
-# --- set status
-ph.setStatusByLimit $iMax $iWarnLimit $iCriticalLimit
-ph.status "DNS check - found maximum was $iMax ms"
+ph.status "DNS check for $myHost - found maximum was $iMax ms - $iNotReachable of $iCounter nameservers not reachable"
cat $infofile
rm -f $tmpfile $infofile
--
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