nagios pnp - nagios脚本支持pnp绘图

【简单介绍】
这里介绍如何编写nagios脚本支持nagios图形化界面。重点在脚本的返回值的格式上。

【简单实例】

#!/bin/bash

# Determine memory usage percentage on Linux servers.

# Original write for RHEL3 for PC1 Project - jlightner 05-Jul-2005

#

# Modified for RHEL5 on mailservers.

# -Some of the escapes previously required for RHEL3's ksh not needed on RHEL5.

# -Changed comparisons to allow for decimal rather than integer values.

# jlightner 23-Jan-2009

#

# Usage: check_mem.sh WARNING CRITICAL

# Where WARNING and CRITICAL are the integer only portions of the

# percentage for the level desired.

# (i.e. 85% Warning & 95% Critical should be input only as "85 95".)

# Define Levels based on input

#

WARN=$1

CRIT=$2

# Setup standard Nagios/NRPE return codes

#

# Give full paths to commands - Nagios can't determine location otherwise

#

BC=/usr/bin/bc

GREP=/bin/grep

AWK=/bin/awk

FREE=/usr/bin/free

TAIL=/usr/bin/tail

HEAD=/usr/bin/head

# Get memory information from the "free" command - output of top two lines

# looks like:

# total used free shared buffers cached

# Mem: 8248768 6944444 1304324 0 246164 5647524

# The set command will get everything from the second line and put it into

# posiional variables $1 through $7.

#

set `$FREE |$HEAD -2 |$TAIL -1`

# Now give variable names to the positional variables we set above

#

MEMTOTAL=$2

MEMUSED=$3

MEMFREE=$4

MEMBUFFERS=$6

MEMCACHED=$7

# Do calculations based on what we got from free using the variables defined

#

REALMEMUSED=`echo $MEMUSED - $MEMBUFFERS - $MEMCACHED | $BC`

USEPCT=`echo "scale=3; $REALMEMUSED / $MEMTOTAL * 100" |$BC -l`

REALMEMUSEDmb=`echo "($REALMEMUSED)/1024" | $BC`

# Compare the Used percentage to the Warning and Critical levels input at

# command line. Issue message and set return code as appropriate for each

# level. Nagios web page will use these to determine alarm level and message.

#

#if [ `echo "5.0 > 5" |bc` -eq 1 ]

#then echo it is greater

#else echo it is not greater

#fi

if [ "`echo "$USEPCT > $CRIT" |bc`" == 1 ]

then echo "MEM CRITICAL - Memory usage = ${USEPCT}%, RealUsed=${REALMEMUSEDmb}MB |Used=${USEPCT}%;REALMEMUSED=${REALMEMUSEDmb}MB"

exit 2

elif [ "`echo "$USEPCT > $WARN" |bc`" == 1 ]

then echo "MEM WARNING - Memory usage = ${USEPCT}%, RealUsed=${REALMEMUSEDmb}MB |Used=${USEPCT}%;REALMEMUSED=${REALMEMUSEDmb}MB"

exit 1

elif [ "`echo "$USEPCT < $WARN" |bc`" == 1 ]

then echo "MEM OK - Memory usage = ${USEPCT}%, RealUsed=${REALMEMUSEDmb}MB|Used=${USEPCT}%;REALMEMUSED=${REALMEMUSEDmb}MB"

exit 0

else echo "MEM ERROR - Unable to determine memory usage"

exit 3

fi

echo "Unable to determine memory usage."

exit 3

正常情况下nagios脚本返回的值就是一个字符串变量，显示在“Status Information”列上。
为了支持pnp获取nagios的返回值，脚本返回中"|"号后的内容作为性能数据。
格式：

引用

'label'=value[UOM];[warn];[crit];[min];[max]

注意：

1. 多个性能数据之间用空格分割

2. label 可以包含任何字符

3. 如果label中包含空格、等号、或者单引号，则label需要用单引号来括起来

4. warn/crit/min/max可以为null值

value, min and max只能为负号“-” “0到9” 和小数点“.” 并且单位必须统一

例如：cpu_user=0.5%;99.9;-9;

5. 如果UOM单位是%，则min和max不需要再指定

6. UOM单位可以是如下： 默认空，表示数量（用于用户数、处理器数等）

       s    表示秒（也可以用us，ms）

       %   表示百分比

       B    表示字节（也可以用KB,MB,TB,GB）

       c    一个连续的计数（如：接口传输的字节数)

如内存监控的数据：

    # /usr/local/nagios/libexec//check_mem 90 95

    MEM OK - Memory usage = 18.700%, RealUsed=3003MB|Used=18.700%;REALMEMUSED=3003MB

图片显示：



【参考引用】
http://blog.chinaunix.net/uid-25266990-id-3437195.html