Compare iocage jail version against the host - nagios check

check_host_vs_jails.sh

#!/bin/sh

HOSTVERSION=`/usr/bin/file /bin/sh`

JAILS=`/usr/local/sbin/iocage list | /usr/bin/egrep -v '^JID' | /usr/bin/cut -f 2 -w`
ERRORS=''
for jail in ${JAILS}
do
  JAILVERSION=`/usr/local/sbin/iocage chroot ${jail} 'file /bin/sh'`
  if [ "${JAILVERSION}" != "${HOSTVERSION}" ]
  then
    ERRORS="jail '${jail}' is ${JAILVERSION} ${ERRORS}"
  fi
done

if [ "${ERRORS}" == "" ]
then
  echo 'All jails match the host'
  exit 0
else
  echo "WARNING: HOST and jails are NOT in sync: host = ${HOSTVERSION} but ${ERRORS}"
  exit 2
fi