五，利用插件扩展Nagios的监控功能
下面我们通过在nagios服务端和客户端安装NRPE插件来搭建一个更加完善的Nagios监控系统。
1）配置nagios客户端（即远端被监控主机192.168.1.2）
A）安装Nagios插件
登陆192.168.1.2客户端
[root@localhost ~]# cd /aaa/
[root@localhost aaa]# useradd -s /sbin/nologin nagios
[root@localhost aaa]# tar zxf nagios-plugins-1.4.14.tar.gz
[root@localhost aaa]# cd nagios-plugins-1.4.14
[root@localhost nagios-plugins-1.4.14]# ./configure ; make ;make install
[root@localhost nagios-plugins-1.4.14]# chown nagios:nagios /usr/local/nagios/
[root@localhost nagios-plugins-1.4.14]# chown -R nagios.nagios /usr/local/nagios/libexec/
B）安装NRPE插件
[root@localhost aaa]# cd /aaa/
[root@localhost aaa]# tar zxf nrpe-2.12.tar.gz
[root@localhost aaa]# cd nrpe-2.12
[root@localhost nrpe-2.12]# ./configure ; make all ; make install-plugin ; make install-daemon ; make install-daemon-config
C）修改NRPE配置文件
[root@localhost nrpe-2.12]# vi /usr/local/nagios/etc/nrpe.cfg
79 allowed_hosts=127.0.0.1,192.168.1.1
192.168.6.199：指定nagios服务器地址
D）启动NRPE
[root@localhost nrpe-2.12]# /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d
[root@localhost nrpe-2.12]# netstat -antl |grep 5666
tcp 0 0 0.0.0.0:5666 0.0.0.0:* LISTEN
E)测试NRPE
[root@localhost nrpe-2.12]# /usr/local/nagios/libexec/check_nrpe -H 127.0.0.1
NRPE v2.12
如果出现NRPE v2.12表明NRPE已经正常工作
定义让nagios服务器监控我本机上的内容（当前用户数，CPU，内存，硬盘等信息）
[root@localhost libexec]# vi /usr/local/nagios/etc/nrpe.cfg
199 command[check_users]=/usr/local/nagios/libexec/check_users -w 5 -c 10
200 command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 - c 30,25,20
201 command[check_sda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10 % -p /dev/sda1
202 command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z
203 command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 1 50 -c 200
重启NRPE
[root@localhost ~]# ps -elf |grep nrpe
5 S nagios 22379 1 0 75 0 - 1243 - 17:59 ? 00:00:00 /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d
0 R root 22586 4247 0 78 0 - 1039 - 18:09 pts/0 00:00:00 grep nrpe
[root@localhost ~]# kill -9 22379
[root@localhost ~]# /usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg –d
2，配置nagios服务器端
登陆nagios服务器端：192.168.1.1
1）安装NRPE插件
[root@localhost etc]# cd /aaa/
[root@localhost aaa]# tar zxf nrpe-2.12.tar.gz
[root@localhost aaa]# cd nrpe-2.12
[root@localhost nrpe-2.12]# ./configure ; make ; make install-plugin
2)测试插件能否取得与客户端192.168.1.2的联系
[root@localhost nrpe-2.12]# /usr/local/nagios/libexec/check_nrpe -H 192.168.1.2
NRPE v2.12
出现NRPE v2.12就证明成功联系上客户端
3）定义一个check_nrpe监控命令
[root@localhost nrpe-2.12]# vi /usr/local/nagios/etc/commands.cfg
define command{
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}
5）添加远程主机监控项
[root@localhost nrpe-2.12]# vi /usr/local/nagios/etc/services.cfg
define service{
use local-service
host_name mysql
service_description users
check_command check_nrpe!check_users
}
define service{
use local-service
host_name mysql
service_description load
check_command check_nrpe!check_load
}
define service{
use local-service
host_name mysql
service_description disk
check_command check_nrpe!check_sda1
}
define servicegroup{
servicegroup_name servergroup
alias server-group
members web,PING,web,SSH,web,SSHD,web,http,mysql,users,mysql,load,mysql,disk
}
6)测试并重新启动nagios服务
[root@localhost ~]# service nagios restart
