Certificate check for Check_MK

check_certs.sh

#! /bin/bash

shopt -s nullglob

DAYS_WARN=21
DAYS_CRIT=7

for CONF_FILE in /etc/apache2/sites-enabled/*_https.conf; do
    DOMAIN_NAME=$(grep ServerName ${CONF_FILE} | awk '{print $2}')
    CERT_FILE=$(grep SSLCertificateFile ${CONF_FILE} | cut -d \" -f 2)

    EXPIRE_DATE=$(openssl x509 -in ${CERT_FILE} -noout -enddate | cut -d = -f 2)
    DAYS_LEFT=$(echo "(" $(date -d "${EXPIRE_DATE}" +%s) - $(date +%s) ")" / 86400 | bc)

    if [ ${DAYS_LEFT} -gt ${DAYS_WARN} ]; then
        STATUS=0
    elif [ ${DAYS_LEFT} -gt ${DAYS_CRIT} ]; then
        STATUS=1
    else
        STATUS=2
    fi

    echo "${STATUS} Certificate_${DOMAIN_NAME} days=${DAYS_LEFT} Certificate expires in ${DAYS_LEFT} days (${EXPIRE_DATE})"
done