Shell Programming and Scripting

#!/bin/bash

STATE=`echo "show State:/Network/Interface/bond0/Link" | scutil | grep -c "TRUE"`

while [ ! ${STATE} -eq 1 ]
do
echo "Link is inactive"
/bin/sleep 2
done

echo "Link is alive"

#!/bin/bash

# Script to call external monitor scripts
# This is run via Launchd

###
# Setup Email
###
C_NAME=`/usr/sbin/scutil --get ComputerName`
NOTIFY="admin@admin.com"
WARNING="There is a problem with the NIC's on the primary Moodle server."
###
# End setup Email
###

TIME="0"
# The loop is for 150 times
# 150x2(sleep time)=300s=5minutes
# If this script continues to fail
# after 5 minutes it will finish the loop
# and then email the admin with necessary info
		
while [ ${TIME} -ne 150 ]
do
        
	# Sleep for 2 seconds in between to preserve
	# processor hogging

   	/bin/sleep 2
      	
	# Check state of aggregated link and interfaces associated
	# with it. Apache will not run unitl NICs are up and running
	# so the remainder of this script will fail.
		
	if [ ! $(echo "show State:/Network/Interface/bond0/Link" | scutil \
	| grep -c "TRUE") -eq 1 ]
	then
		echo Loop ${TIME}
                echo "Interface is not active"
       	        TIME=$(( ${TIME} + 1 ))
   	else 
		echo "Interface is alive"

		# Sleep to allow Apache time to start.
		# If Apache fails after this amount of
		# time, then there is something wrong
		# and shutdown_services script will be
		# called to initiate failover
			
		/bin/sleep 30

		echo "Running monitor scripts"
			
		# Call check_apache.sh script
		APACHE="/Library/IPFailover/scripts/check_apache.sh"
			
		if [ -x ${APACHE} ]
		then
			/Library/IPFailover/scripts/check_apache.sh
		else
			echo "check_apache.sh does not exist - moving to next script"
			logger \
			"FAILOVER: check_apache.sh does not exist - moving to next script"
		fi

		# Call check_php.sh script
		PHP="/Library/IPFailover/scripts/check_php.sh"
			
		if [ -x ${PHP} ]
		then
			/Library/IPFailover/scripts/check_php.sh
		else
			echo "check_php.sh does not exist - moving to next script"
			logger \
			"FAILOVER: check_php.sh does not exist - moving to next script"
		fi

		# Call check_postgres.sh script
		POSTGRES="/Library/IPFailover/scripts/check_postgres.sh"
			
		if [ -x ${POSTGRES} ]
		then
			/Library/IPFailover/scripts/check_postgres.sh
		else
			echo "check_postgres.sh does not exist - moving to next script"
			logger \
			"FAILOVER: check_postgres.sh does not exist - moving to next script"
		fi

		# Exit the script and therefore the loop
       	        # Using "break" would only exit the loop
		# and not exit the script
       	        # We don't need to email Admins
       	        # when the script is successful
                        
		exit 0
	fi
done

echo "Finished looping"
echo "Mailing the admin"
logger "FAILOVER: Problem with Network Interfaces - mailing the admin and exiting monitor.sh script"

# Mail the System Administrator

echo From: $C_NAME - ${WARNING} > /tmp/monitor_warning.txt
echo ----- >> /tmp/monitor_warning.txt
echo "Note that there has been a bad response from the "monitor" shell script."\
>> /tmp/monitor_warning.txt
echo "This means that there is a problem with the Network Interfaces of $C_NAME providing the Moodle service." \
>> /tmp/monitor_warning.txt
echo ----- >> /tmp/monitor_warning.txt
echo "This error was written out at `date`." >> /tmp/monitor_warning.txt
echo ----- >> /tmp/monitor_warning.txt
echo "Please attend to this immediately." >> /tmp/monitor_warning.txt
cat /tmp/monitor_warning.txt | mail -s \
"From: ${C_NAME} - Primary NIC's are down" ${NOTIFY}

# Should I instigate failover here?

exit 0