Laufzeit von Zertifikaten mit Check_MK prüfen

#!/bin/bash
# Plugin Return Codes
# = 0   OK
# = 1   Warning
# = 2   Critical
# = 3   Unknown
#
DIR=/etc/letsencrypt/live/*/
FILTER=$DIR/cert.pem
 
function output {
 NAME=$(basename $1)
 DATE=$(date --date="$2" --iso-8601)
 SUBJECT=$3
 
 TODAY=$(date +%s)
 DATE_I=$(date -d ${DATE} +%s)
 EXPIRATION=$((15 * 24 * 60 * 60)) # 15 days
 
 if [[ -z $SUBJECT ]] ; then
  STATUS=3
  STATUS_TEXT="UNKNOWN"
  TEXT="Empty subject value"
 elif [ ${TODAY} -gt ${DATE_I} ] ; then
  STATUS=2
  STATUS_TEXT="CRITICAL"
  TEXT="Certificate has expired since ${DATE}"
 elif [[ $(expr $TODAY + $EXPIRATION) -gt ${DATE_I} ]] ; then
  STATUS=1
  STATUS_TEXT="WARNING"
  TEXT="Certificate will expire on ${DATE}"
 else
  STATUS=0
  STATUS_TEXT="OK"
  TEXT="Certificate will expire on ${DATE}"
 fi
 
 echo "${STATUS:-1} Certificate_${SUBJECT} Date=${DATE}; Check(${STATUS_TEXT}) - ${TEXT} - ${SUBJECT}"
}
 
function check {
 FILE=$1
 DATE=$(cat ${FILE} |openssl x509 -noout -enddate|cut -d= -f2-)
 SUBJECT=$(cat ${FILE} |openssl x509 -noout -subject|cut -d= -f3-)
 output "$FILE" "$DATE" "$SUBJECT"
}
 
for FILE in $FILTER;
do
  # take action on each certificate file.
  check "$FILE"
done