Check active server in DNS failover pair

root@com6-prod-nagios01:/etc/nagios3/conf.d# cat /root/nagios/check_primary_server/check_primary_server.sh 
#!/bin/bash
#Written Andrew Stringer 18/08/2016.
#Purpose is to show which is the master server from a xxxx


#Retcode 0 = OK
#Retcode 1 = Warning
#Retcode 2 = Critical
#Retcode 3 = Unknown


#Nagios Config
#Check which service is Live!

#define command {
#                command_name    check_primary_server
#                command_line    /usr/lib/nagios/plugins/check_primary_server.sh '$ARG1$'
#                }

## Dummy host to pin services to
#define host{
#        use             generic-host
#        host_name       ActiveServers
#        alias           ActiveServers
#        address         127.0.0.1
#        hostgroups      ActiveServers
#        icon_image      base/icon.png
#        #contact_groups  unixadmin
#        notes_url       https://wiki.int/page.php?id=troubleshooting:active-servers
#        parents         sw1, sw2
#        }

#define hostgroup{
#        hostgroup_name  ActiveServers
#        alias           Active Server
#        }

#define service {
#        use                             generic-service
#        host_name                       ActiveServers
#        service_description             Check active STAG Memcache
#        check_command                   check_primary_server!stag-memcache.int.zone.
#        contact_groups                  unixadmin
#        }
        
#Start of code        
        

error() { echo "DNS name is required. Usage:- check_primary_server.sh DNS-name" 1>&2; exit 3; }

#Check we have some arguments passed
if [ -z "$1" ] ; then
        error
        exit 3
else
        LIVEHOST_TMP=`host ${1}`
        RETCODE=$?
        #echo "${LIVEHOST_TMP}"

        CNAME=`echo ${LIVEHOST_TMP} | grep alias` 2>&1 > /dev/null
        CNAMERC=$?
        #echo "cnamerc is $CNAMERC"
        #check if we get an A record returned, if so, the address we are being fed with is wrong. Exit with error
        if [[ $RETCODE == 0 ]] && [[ $CNAMERC == 1 ]] ; then
                echo "CNAME required, you have supplied an A record!"
                exit 3
        fi




        if [[ $RETCODE == 0 ]] ; then
                LIVEHOST=`echo ${LIVEHOST_TMP} | grep alias | cut -d' ' -f 6 | cut -d. -f1`
                TEXT="Active server is ${LIVEHOST}"
                STATUS=0
        elif [[ $RETCODE == 2 ]]; then
                LIVEHOST="invalid"
                TEXT="DNS name is unresolvable."
                STATUS=2
        else
                TEXT="Unknown Error"
                STATUS=3
        fi

        #echo "ret $STATUS  -- $LIVEHOST"
fi







#exit from check.
if [[ $STATUS -eq 0 ]]; then
        echo "${TEXT}"
        exit 0
elif [[ $STATUS -eq 1 ]]; then
        echo "${TEXT}"
        exit 
elif [[ $STATUS -eq 2 ]]; then
        echo "${TEXT}"
        exit 2
else
        echo "${TEXT}"
        exit 3
fi

exit 0