check_redis.sh脚本内容并控制keepalived的权重级

以下是一个例子：

#!/bin/bash
REDIS_CLI="/usr/local/bin/redis-cli"
REDIS_IP="127.0.0.1"
REDIS_PORT="6379"
REDIS_PASSWORD="your_redis_password"
MASTER_WEIGHT=200
BACKUP_WEIGHT=100

# check redis status
$REDIS_CLI -h $REDIS_IP -p $REDIS_PORT -a $REDIS_PASSWORD ping | grep -q PONG

if [ $? -ne 0 ]; then
   # Redis is down, set priority to 0 to trigger failover
   echo "Failed"
   echo "state changed to FAULT" > /tmp/redis_state
   echo "state changed to FAULT" | systemd-cat -t keepalived-check-redis
   exit 1
else
   # Redis is up, set priority based on role
   role=$($REDIS_CLI -h $REDIS_IP -p $REDIS_PORT -a $REDIS_PASSWORD info replication | grep role | awk -F':' '{print $2}' | tr -d '\r\n')
   if [ "$role" == "master" ]; then
      echo "Master"
      echo "state changed to MASTER" > /tmp/redis_state
      echo "state changed to MASTER" | systemd-cat -t keepalived-check-redis
      echo "MASTER"
      exit 0
   else
      echo "Slave"
      echo "state changed to BACKUP" > /tmp/redis_state
      echo "state changed to BACKUP" | systemd-cat -t keepalived-check-redis
      echo "BACKUP"
      exit 0
   fi
fi

该脚本的主要作用是检查redis的状态，并根据redis的角色（主从）来设置keepalived的权重级。如果redis宕机，脚本将会返回"Failed"并以1的状态码退出，同时将keepalived的状态设置为FAULT。如果redis正常运行，脚本将会根据redis的角色来设置权重级，如果redis是主节点，脚本将会返回"Master"并以0的状态码退出，同时将keepalived的状态设置为MASTER；如果redis是从节点，脚本将会返回"Slave"并以0的状态码退出，同时将keepalived的状态设置为BACKUP。

该脚本还可以根据具体的需求进行修改，比如更改权重级、增加其他检查项等。此外，为了让keepalived监控到脚本的输出，还需要将脚本的输出重定向到systemd的日志中，可以使用systemd-cat命令实现。