作为Nagios的一个扩展功能插件，NRPE可在远程的linux主机上执行的插件程序。远程的liux服务器通过安装NRPE及Nagios的相关插件程序可以向Nagios服务端监控平台提供自身的情况例如：CPU负载，内存使用以及磁盘使用等情况。这里依旧将node1.cn主机作为Nagios监控端，node2.cn作为被监控端。
一、NRPE简介
Nrpe作为Nagios的一个扩展功能，其可以在远程Linux主机上执行插件程序，通过远程服务器自身安装的NRPE插件和Nagios插件程序向Nagios监控平台提供自身负载：CPU负载，内存使用以及磁盘使用等等。
NRPE作为Nagios远程主机监控插件，它被用于让Nagios监控端基于安装的方式触发远端主机检测指令，并发送给Nagios监控端。且执行开销低于SS和的检查方式，并由检测过程不需要远程主机上的系统账号信息，因此安全性方面优于SSH的检测方式。
1.1 NRPE工作原理
NRPE构成：
check_nrpe:位于监控主机
nrpe daemon：位于远程主机(npre daemon需要Nagios-plugins插件的支持，否则daemon在远程主机无效)
Nagios监控某个远程linux主机的服务或资源的过程如下：
第一：Nagios运行check_nrpe插件，使nrpe知道需要做什么检查；
第二：check_nrpe插件会链接到远程的daemon，所用的方式是SSL；
第三：NRPE daemon运行相应Nagios插件执行相关检查；
最后：NRPE daemon将检查结果返回check_nrpe插件，进而check_nrpe将结果递交给Nagios进行处理。
二、远程主机Nagios-plugins插件和NRPE的安装
2.1添加运行用户nagios
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[root@node2 src]
# useradd -s /sbin/nologin nagios
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2.2安装nagios-plugins插件
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[root@node2 src]
# yum -y install gcc gcc-c++ make openssl openssl-devel
[root@node2 src]
#cd /usr/local/src/
[root@node2 src]
#tar xvf nagios-plugins-2.2.1.tar.gz
[root@node2 src]
#cd nagios-plugins-2.2.1
[root@node2 nagios-plugins-2.2.1]
# ./configure --with-nagios-user=nagios --with-nagios-group=nagios
[root@node2 nagios-plugins-2.2.1]
# make && make install
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2.3安装nrpe
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[root@node2 src]
# tar xvf nrpe-2.15.tar.gz
[root@node2 src]
# cd nrpe-2.15
[root@node2 nrpe-2.15]
# ./configure --with-nrpe-user=nagios --with-nrpe-group=nagios --with-nagios-user=nagios --enable-command-args --enable-ssl
*** Configuration summary
for
nrpe 2.15 09-06-2013 ***:
General Options:
-------------------------
NRPE port: 5666
NRPE user: nagios
NRPE group: nagios
Nagios user: nagios
Nagios group: nagios
Review the options above
for
accuracy. If they
look
okay,
type
'make all'
to compile the NRPE daemon and client.
[root@node2 nrpe-2.15]
# make all
[root@node2 nrpe-2.15]
# make install-plugin
cd
.
/src/
&&
make
install
-plugin
[root@node2 nrpe-2.15]
# make install-daemon
cd
.
/src/
&&
make
install
-daemon
[root@node2 nrpe-2.15]
# make install-daemon-config
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2.4 配置NRPE
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[root@node2 ~]
# grep -E -v "^#|^$" /usr/local/nagios/etc/nrpe.cfg
log_facility=daemon
pid_file=
/var/run/nrpe
.pid
server_port=5666
nrpe_user=nagios
nrpe_group=nagios
allowed_hosts=127.0.0.1,192.168.31.101
#允许的地址，在127.0.0.1后添加nagios服务器地址即可，以都好分割
dont_blame_nrpe=0
allow_bash_command_substitution=0
debug=0
command_timeout=60
connection_timeout=300
command
[check_users]=
/usr/local/nagios/libexec/check_users
-w 5 -c 10
command
[check_load]=
/usr/local/nagios/libexec/check_load
-w 15,10,5 -c 30,25,20
command
[check_hda1]=
/usr/local/nagios/libexec/check_disk
-w 20% -c 10% -p
/dev/hda1
command
[check_zombie_procs]=
/usr/local/nagios/libexec/check_procs
-w 5 -c 10 -s Z
command
[check_total_procs]=
/usr/local/nagios/libexec/check_procs
-w 150 -c 200
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2.5 NRPE守护进程启动
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[root@node2 ~]
# /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d
[root@node2 ~]
# netstat -tulpn | grep nrpe
tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN 26018
/nrpe
tcp 0 0 :::5666 :::* LISTEN 26018
/nrpe
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NRPE的运行模式：
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-i = Run as a service under inetd or xinetd
-d = Run as a standalone daemon
-d -s = Run as a subsystem under AIX
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2.6 nrpe启动脚本的编辑
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[root@node2 ~]
# vim /etc/init.d/nrped
#!/bin/bash
#date: 2017-11-05
# chkconfig: - 64 36
# description: NRPE server.
NPRE=
/usr/local/nagios/bin/nrpe
NRPECFG=
/usr/local/nagios/etc/nrpe
.cfg
case
"$1"
in
start)
echo
-n
"Starting NPRE daemon..."
${NPRE} -c ${NRPECFG} -d
echo
"Start NPRE daemon done..."
;;
stop)
echo
-n
"stopping NRPE daemon..."
pkill -u nagios nrpe
echo
"Stop NPRE daemon done..."
;;
restart)
$0 stop
sleep
3
$0 start
;;
*)
echo
"Usage:$0 start|stop|restart"
;;
esac
exit
0
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2.7 nrped脚本测试和设置nrped服务开机启动启动
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[root@node2 ~]
# chkconfig nrped on
[root@node2 ~]
# service nrped restart
stopping NRPE daemon...Stop NPRE daemon
done
...
Starting NPRE daemon...Start NPRE daemon
done
...
[root@node2 ~]
# netstat -tnlp | grep nrpe
tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN 26085
/nrpe
tcp 0 0 :::5666 :::* LISTEN 26085
/nrpe
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3 Nagios服务端安装NRPE
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[root@node1 src]
# tar xvf nrpe-2.15.tar.gz
[root@node1 nrpe-2.15]
# ./configure --with-nrpe-user=nagios --with-nrpe-group=nagios --with-nagios-user=nagios --with-nagios-group=nagios --enable-command-args --enable-ssl
[root@node1 nrpe-2.15]
# make all
[root@node1 nrpe-2.15]
# make install-plugin
[root@node1 nrpe-2.15]
# ls /usr/local/nagios/libexec/check_nrpe
/usr/local/nagios/libexec/check_nrpe
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3.1 关于check_nrpe的一些用法
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[root@node1 libexec]
# /usr/local/nagios/libexec/check_nrpe -h
NRPE Plugin
for
Nagios
Copyright (c) 1999-2008 Ethan Galstad (nagios@nagios.org)
Version: 2.15
Last Modified: 09-06-2013
License: GPL v2 with exemptions (-l
for
more
info)
SSL
/TLS
Available: Anonymous DH Mode, OpenSSL 0.9.6 or higher required
Usage: check_nrpe -H <host> [ -b <bindaddr> ] [-4] [-6] [-n] [-u] [-p <port>] [-t <timeout>] [-c <
command
>] [-a <arglist...>]
Options:
-n = Do no use SSL
-u = Make socket timeouts
return
an UNKNOWN state instead of CRITICAL
<host> = The address of the host running the NRPE daemon
<bindaddr> = bind to
local
address
-4 = user ipv4 only
-6 = user ipv6 only
[port] = The port on
which
the daemon is running (default=5666)
[timeout] = Number of seconds before connection
times
out (default=10)
[
command
] = The name of the
command
that the remote daemon should run
[arglist] = Optional arguments that should be passed to the
command
. Multiple
arguments should be separated by a space. If provided, this must be
the last option supplied on the
command
line.
Note:
This plugin requires that you have the NRPE daemon running on the remote host.
You must also have configured the daemon to associate a specific plugin
command
with the [
command
] option you are specifying here. Upon receipt of the
[
command
] argument, the NRPE daemon will run the appropriate plugin
command
and
send the plugin output and
return
code back to *this* plugin. This allows you
to execute plugins on remote hosts and
'fake'
the results to
make
Nagios think
the plugin is being run locally.
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相关语法格式：
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[root@node1 libexec]
# ./check_nrpe -H <host> [-n] [-u] [-p <port>] [-t <timeout>] [-a <arglist...>]
[root@node1 libexec]
# ./check_nrpe -H 192.168.31.102
NRPE v2.15
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3.2 定义相关命令
[root@node1 libexec]# cd /usr/local/nagios/etc/objects/
添加内容到commands.cfg末尾
[root@node1 objects]# vim commands.cfg
define command{
command_name check_nrpe
command_line USER1/check_npre -H "HOSTADDRESS" -c "ARG1"
}
3.3 添加nagios.cfg配置文件内容
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[root@node1 objects]
# vim /usr/local/nagios/etc/nagios.cfg
cfg_file=
/usr/local/nagios/etc/objects/linehost
.cfg
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3.4 定义主机linehost.cfg和服务service.cfg
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[root@node1 objects]
# grep -E -v "^#|^$" linehost.cfg
define host{
use linux-server ; Name of host template to use
; This host definition will inherit all variables that are defined
;
in
(or inherited by) the linux-server host template definition.
host_name linehost
alias
linehost
address 192.168.31.102
}
define hostgroup{
hostgroup_name my-linux-servers ; The name of the hostgroup
alias
My Linux Servers ; Long name of the group
members linehost ; Comma separated list of hosts that belong to this group
}
[root@node1 objects]
# vim services.cfg
define service{
use
local
-service
host_name linehost
service_groups MysqlGroup
service_description MySqlSev
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check_command check_mysql
}
define service{
use
local
-service ; Name of service template to use
host_name linehost
service_description PING
check_commandcheck_ping!100.0,20%!500.0,60%
}
define service{
use
local
-service ; Name of service template to use
host_name linehost
service_description Root Partition
check_commandcheck_local_disk!20%!10%!/
}
define service{
use
local
-service ; Name of service template to use
host_name linehost
service_description Current Users
check_commandcheck_local_users!20!50
}
define service{
use
local
-service ; Name of service template to use
host_name linehost
service_description Total Processes
check_commandcheck_local_procs!250!400!RSZDT
}
检查配置文件
[root@node1 objects]
# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
无错误信息重启服务
[root@node1 objects]
# service nagios restart
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web端进行查看验证
Nagios通过NRPE对远程linux服务器监控就介绍到这里，下一章将介绍Nagios对windowns主机的监控以及的邮件报警功能的配置
博文出自：http://os.51cto.com/art/201409/452605.htm
本文转自 CARYFLASH 51CTO博客，原文链接:http://blog.51cto.com/maoxiaoxiong/1980787
