nagios检测cpu的插件(bash脚本)

#!/bin/bash
#如果某些命令找不到，可以在此定义$PATH。
#使用方法：直接执行脚本，无需其它参数，使用iostat命令获得服务器CPU状态的值，并返回给Nagios及Nagios插件pnp #

# 状态定义
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
STATE_DEPENDENT=4

# 将执行6次的结果写入文件
touch /tmp/iostat.log
iostat -c 1 6 >/tmp/iostat.log
if [ $? -ne 0 ]
then
  echo "Error : Can't find the command 'iostat' ."
 exit "$STATE_UNKNOWN"
fi
# 判断文件是否存在
if [ ! -f /tmp/iostat.log ]
then
 echo "Error : iostat.log not found ."
 exit "$STATE_UNKNOWN"
fi

# 赋值，取6次结果中的后5次的平均值
float_user=`cat /tmp/iostat.log |grep -v % |grep -v ^$ |sed '1,2d' |awk '{a+=$1}END{printf "%.0f",a/5}'`
float_system=`cat /tmp/iostat.log |grep -v % |grep -v ^$ |sed '1,2d' |awk '{a+=$3}END{printf "%.0f\n",a/5}'`
float_idle=`cat /tmp/iostat.log |grep -v % |grep -v ^$ |sed '1,2d' |awk '{a+=$6}END{printf "%.0f\n",a/5}'`
float_iowait=`cat /tmp/iostat.log |grep -v % |grep -v ^$ |sed '1,2d' |awk '{a+=$4}END{printf "%.0f\n",a/5}'`

# 删除iostat日志文件
if [ -f /tmp/iostat.log ]
then
 rm -f /tmp/iostat.log
fi

# 计算CPU使用率
used_idle=`awk "BEGIN{print (100-$float_idle)}"`

# 判断取到的值是否在正确范围
if [ $used_idle -lt 0 -o $used_idle -gt 100 ]
then
 echo "Error : used_idle out of the correct range ."
 exit "$STATE_UNKNOWN"
fi

# 定义报警阈值，这里为百分数，请不要添加‘%’
critical=90
warning=80

# 定义报警输出
stat_ok="OK"
stat_warning="WARNING"
stat_critical="CRITICAL"
stat_unknown="UNKNOWN"
stat_info="User=${float_user}% System=${float_system}% Iowait=${float_iowait}% Idle=${float_idle}% | CPU_Used=${used_idle}%"

# 判断并返回相应的值
if [ ${used_idle} -lt $warning ]
    then
    echo "${stat_ok} : ${stat_info}"
    exit "$STATE_OK"

elif [ ${used_idle} -ge $warning -a ${used_idle} -lt $critical ]
    then
    echo "${stat_warning} : ${stat_info}"
    exit "$STATE_WARNING"

elif [ ${used_idle} -ge $critical ]
    then
    echo "${stat_critical} : ${stat_info}"
    exit "$STATE_CRITICAL"

else
    echo "${stat_unknown} : ${stat_info}"
    exit "$STATE_UNKNOWN"
fi