whoIsMasterRedis.sh

#!/bin/bash

#Redis Servers
array=( cache2 cache1 cache3 )

#output file
outputConfig='/config/redis.json'

function outputRedisConfig {
echo "{
    \"RedisServers\": {
        \"frontend\": {
            \"uri\": \"tcp://$1:6379\",
            \"timeout\": 5
        },
        \"backend\": {
            \"uri\": \"tcp://$1:6379\",
            \"timeout\": 5
        }
    }
}" > $outputConfig
}

currentMaster='';
if [ -f /var/log/lastRedisMaster ]; then
currentMaster=$(cat /var/log/lastRedisMaster)
fi

for i in "${array[@]}"
do
	resp=$(redis-cli -h $i info | grep role:master)
	if [ $resp ];
	then
		if [ "$currentMaster" != "$i" ];
		then
			outputRedisConfig $i
			echo "$i" > /var/log/lastRedisMaster
			service apache2 restart
			break;
		fi
	fi
done