Nagios监控--Linux客户端（Use NRPE）


Nagios监控--Linux客户端（Use NRPE）

一、实验环境

监控服务器（nagios服务器--192.168.1.100）

CentOS5.4 + nagios-3.2.1 + nagios-plugins-1.4.14 + nrpe-2.12

被监控客户端（linux客户端--192.168.1.200）

CentOS5.4 + nagios-plugins-1.4.14 + nrpe-2.12

二、nrpe插件

1、nrpe插件的组成

NRPE总共由两部分组成：

（1）check_nrpe：它是运行在监控主机上

（2）NRPE daemon：它是运行在远程的linux主机上（通常就是被监控机）

2、nrpe的工作原理



当Nagios需要监控某个远程linux主机的服务或者资源情况时

第一步：nagios服务器运行check_nrpe插件，我们要在nagios配置文件中告诉它要检查什么

第二步：check_nrpe插件会通过SSL连接到远程的被监控的Linux客户端上的NRPE daemon

第三步：被监控的Linux客户端上的NRPE daemon会运行相应的nagios插件来执行检查本地资源或服务

第四步：被监控的Linux客户端上的NRPE daemon的NRPE daemon将检查的结果返回给check_nrpe插件,插件将其递交给进行nagios做处理

注意：NRPE daemon需要nagios-plugin插件安装在远程被监控linux主机上，否则NRPE daemon不能做任何的监控；别外因为它们间的通信是加密的SSL,所以在编译安装时都要加上选项：/configure --enable-ssl --with-ssl-lib=/lib/，否则会出错



三、配置被监控的Linux主机（Linux客户端）

1、安装所需的软件（nagios-plugins、nrpe）

wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.14.tar.gz
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nrpe-2.12.tar.gz
1）安装nagios-plugins

#增加一个用户

useradd nagios

passwd nagios

#解压并安装

tar zvxf nagios-plugins-1.4.14.tar.gz && cd nagios-plugins-1.4.14

./configure --with-nagios-user=nagios --with-nagios-group=nagios && make && make install

chown -R nagios:nagios /usr/local/nagios

2）安装nrpe

tar -zxvf nrpe-2.12.tar.gz && cd nrpe-2.12

./configure --enable-ssl --with-ssl-lib （前提是已经安装了openssl与openssl-devel)

make all && make install-plugin && make install-daemon && make install-daemon-config

3）配置nrpe

#配置nrpe信息

vi /usr/local/nagios/etc/nrpe.cfg，查找并修改如下一行

allowed_hosts=192.168.1.100,127.0.0.1 #注意修改为nagios服务器的IP：192.168.1.100

#配置监控对象

说明：由监控原理可知被监控端做监控，然后将数据传给监控服务器绘总,设置监控详细参数主要是设置被监控端的nrpe.cfg文件，可以看到里面监控对象

vi /usr/local/nagios/etc/nrpe.cfg，查找并修改如下一行

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_disk]=/usr/local/nagios/libexec/check_disk -w 10% -c 5%

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 500 -c 550

command[check_swap]=/usr/local/nagios/libexec/check_swap -w 20% -c 10%

command[check_ping]=/usr/local/nagios/libexec/check_ping -H 192.168.1.1 -w 100.0,20% -c 500.0,60%

............................................#自已添加..........................................................


#command[check_http]=/usr/local/nagios/libexec/check_http -I 127.0.0.1 -w 10 -c 20

#command[check_ssh]=/usr/local/nagios/libexec/check_ssh -4 127.0.0.1

4）启动nrpe，并测试

/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

echo '/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d &> /dev/null' >> /etc/rc.local

netstat -atulnp | grep 'nrpe'

tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN 3308/nrpe

/usr/local/nagios/libexec/check_nrpe -H localhost

NRPE v2.12

5）nrpe常见故障

错误一：/usr/local/nagios/libexec/check_nrpe -H 127.0.0.1

CHECK_NRPE: Error - Could not complete SSL handshake

解析办法：配置allowed_hosts=192.168.1.100,127.0.0.1，然后kill进程再重启就OK了

错误二：/usr/local/nagios/libexec/check_nrpe -H 127.0.0.1

Connection refused by host

解析办法：Nrpe进程没有启动

四、配置监控服务器（Nagios服务器）

1、安装所需的软件（nagios、nagios-plugins、nrpe）

wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.1.tar.gz
wget http://prdownloads.sourceforge.net/sourceforge/nagiosplug/nagios-plugins-1.4.14.tar.gz
wget http://prdownloads.sourceforge.net/sourceforge/nagios/nrpe-2.12.tar.gz
2、安装nagios与nagios-plugins

1）nagios与nagios-plugins的安装

查看：http://hi.baidu.com/9812658/blog/item/ae3632edd4f5afe2ce1b3e0e.html

2）安装nrpe

tar -zxvf nrpe-2.12.tar.gz && cd nrpe-2.12

./configure --enable-ssl --with-ssl-lib （前提是已经安装了openssl与openssl-devel)

make all && make install-plugin && make install-daemon && make install-daemon-config

3）配置nrpe

#在commands.cfg中定义nrpe这个外部构件

vi /usr/local/nagios/etc/nagios.cfg，打开下面这一行

cfg_file=/usr/local/nagios/etc/objects/commands.cfg

vi /usr/local/nagios/etc/objects/commands.cfg，增加如下一行

#check nrpe

define command{

command_name check_nrpe

command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$

}

#配置要监控的linux主机

vi /usr/local/nagios/etc/nagios.cfg，加入如下一行

cfg_file=/usr/local/nagios/etc/objects/mylinux.cfg

touch /usr/local/nagios/etc/objects/mylinux.cfg，增加如下内容

define host{

use linux-server

host_name mylinux

alias mylinux

address 192.168.1.200

}

define service{

use generic-service #使用的是/usr/local/nagios /etc/objects/templates.cfg中所定义的

host_name mylinux

service_description Swap Usage

check_command check_nrpe!check_swap

}

define service{

use generic-service

host_name mylinux

service_description Current Load

check_command check_nrpe!check_load

}

define service{

use generic-service

host_name mylinux

service_description Partition Usage

check_command check_nrpe!check_disk

}

define service{

use generic-service

host_name mylinux

service_description Current Users

check_command check_nrpe!check_users

}

define service{

use generic-service

host_name mylinux

service_description Total Processes

check_command check_nrpe!check_total_procs

}

define service{

use generic-service

host_name mylinux

service_description PING

check_command check_nrpe!check_ping

}

5）启动nrpc，并测试

/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

echo '/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d &> /dev/null' >> /etc/rc.local

netstat -atulnp | grep 'nrpe'

tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN 3308/nrpe

/usr/local/nagios/libexec/check_nrpe -H 192.168.0.6 #linux客户端的IP地址：192.168.0.6

NRPE v2.12

/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

service nagios restart
http://nagios_ip_address/nagios