Redisのロックを取るスクリプト

get-redis-lock.sh

#!/bin/bash
set -ue

node_id=1
lock_key=lock
ttl=10
redis_db=0
redis_host=localhost
redis_port=6379

locked=`redis-cli -h $redis_host -p $redis_port -n $redis_db --raw SETNX $lock_key $node_id`

if [ "$locked" = 1 ];then
    echo "Get lock: keyname: $lock_key"
    result=`redis-cli -h $redis_host -p $redis_port -n $redis_db --raw EXPIRE $lock_key $ttl`
    if [ "$result" = 1 ];then
        echo "Set expire: $ttl"
        exit 0
    elif [ "$result" = 0 ];then
        echo "Couldn't set expire!"
        exit 1
    fi
elif [ "$locked" = 0 ];then
    echo "Couldn't get lock"
    exit 1
else
    echo "Error!"
    exit 1
fi

• 使い方

bash get-redis-lock.sh && echo ok

cronのHAなどに使う想定