nagios监控流量脚本

需求是我们需要对服务器上的流量进行监控，网络上有个流传的check_traffic.sh，它需要被监控机开启snmp。但是感觉都使用上了nagios还要开snmp。。。有点斧子剪刀一起用的感觉，所以就动手写了个监控流量的shell：

#!/bin/sh

usage() { echo "Usage: $0 [-n <eth0>] [-w <tx rx>] [-c <tx rx>]" 1>&2; exit 1; }

foundw=0;
foundc=0;
foundn=0;

for item in $@ ; do
if [[ $foundn == 1 ]]; then
n=$item;
foundn=2;
continue;
fi
if [[ $foundw == 1 ]]; then
w1=$item;
foundw=2;
continue;
fi
if [[ $foundw == 2 ]]; then
w2=$item;
foundw=3;
continue;
fi
if [[ $foundc == 1 ]]; then
c1=$item;
foundc=2;
continue;
fi
if [[ $foundc == 2 ]]; then
c2=$item;
foundc=2;
continue;
fi
if [[ "$item" == "-w" ]]; then
foundw=1;
continue;
fi
if [[ "$item" == "-c" ]]; then
foundc=1;
continue;
fi
if [[ "$item" == "-n" ]]; then
foundn=1;
continue;
fi
done

if [ -z "${w1}" ] || [ -z "${w2}" ] || [ -z "${c1}" ] || [ -z "${c2}" ] || [ -z "${n}" ]; then
usage
fi

R1=`cat /sys/class/net/$n/statistics/rx_bytes`
T1=`cat /sys/class/net/$n/statistics/tx_bytes`
sleep 1
R2=`cat /sys/class/net/$n/statistics/rx_bytes`
T2=`cat /sys/class/net/$n/statistics/tx_bytes`
TBPS=`expr $T2 - $T1`
RBPS=`expr $R2 - $R1`
TMBPS=`expr $TBPS / 1024 / 128`
RMBPS=`expr $RBPS / 1024 / 128`

if [[ $TMBPS -ge $c1 ]] || [[ $RMBPS -ge $c2 ]] ; then
echo "Critical - current is ${TMBPS}, ${RMBPS}";
exit 2;
fi
if [[ $TMBPS -ge $w1 ]] || [[ $RMBPS -ge $w2 ]] ; then
echo "WARNING - current is ${TMBPS}, ${RMBPS}";
exit 1;
fi
echo "OK - current is ${TMBPS}, ${RMBPS}";
exit 0;

其中的w和c的数值单位都是Mb。