安装配置nagios
nagios需要依赖lamp环境，所有我们先在nagios服务器上安装配置lamp环境
[root@localhost ~]# mount /dev/cdrom /media/
[root@localhost ~]# rm -rf /etc/yum.repos.ddhcpd.conf.example /etc/dhcp/dhcpd.conf
cp：是否覆盖"/etc/dhcp/dhcpd.conf"？ y
[root@localhost nrpe-2.15]# vim /etc/dhcp/dhcpd.conf
subnet 192.168.6.0 netmask 255.255.255.0 {
range 192.168.6.26 192.168.6.30;
default-lease-time 600;
max-lease-time 7200;
}
[root@localhost nrpe-2.15]# systemctl restart dhcpd
6、添加被监控客户端的测试选项（server1）
[root@localhost ~]# cd /usr/local/nagios/etc/objects/
[root@localhost objects]# cp -p localhost.cfg 192.168.6.20.cfg
[root@localhost objects]# vim 192.168.6.20.cfg
修改：
删除host group选项
define hostgroup{
hostgroup_name linux-servers ; The name of the hostgroup
alias Linux Servers ; Long name of the group
members localhost ; Comma separated list of hosts that belong to this group
}
define host{
use linux-server
host_name server2
alias server2
address 192.168.6.20
}
替换所有模块中的host_name的名称为server2
:% s/localhost/server2/g
添加模块：
define service{
use local-service
host_name server2
service_description FTP
check_command check_ftp
notifications_enabled 0
}
define service{
use local-service
host_name server2
service_description DHCP
check_command check_dhcp
notifications_enabled 0
}
define service{
use local-service
host_name server2
service_description DNS
check_command check_dns
notifications_enabled 0
}
7、配置nagios.cfg，添加监控节点
[root@localhost objects]# vim /usr/local/nagios/etc/nagios.cfg
添加： 32后
cfg_file=/usr/local/nagios/etc/objects/192.168.6.20.cfg
8、重启服务
killall -9 nagios
systemctl start nagios &
systemctl start httpd
9、查看监控结果
等待一段时间后，会对所有项目进行检测完毕
我们通过结果，可以看到有通过检测的选项(绿色)，警告(黄色)，未知服务(橘色)，最后一列给出了故障和检测信息。http服务标记了403错误，我们给http服务添加一个主页文件。然后等待一下就能看到以下结果。
二、添加mysql监控
1、在mysql服务器（被监控服务器）上配置：
[root@localhost ~]# mysql -u root -p123.com mysql> create database abc;
mysql> grant all on abc.* to 'zhang1'@'192.168.1.%' identified by '123.com'; mysql> flush privileges;
mysql>quit
第1步：在监控服务器上安装mariadb与配套组件
[root@localhost ~]# yum -y install mariadb mariadb-devel
第2步：在nagios监控服务器中配置
1、检测连接数据库服务器
/usr/local/nagios/libexec/check_mysql -u zhang1 -d abc -H 192.168.1.100 -P3306 --password='123.com'
2、定义mysql命令
[root@localhost ~]# vim /usr/local/nagios/etc/objects/commands.cfg
添加：
define command{
command_name
check_mysql
command_line $USER1$/check_mysql -H $HOSTADDRESS$ -P3306 -u zhang1 -d abc --password='123.com'
}
第3步：在主机检测配置文件中添加检测信息
vim /usr/local/nagios/etc/objects/192.168.10.2.cfg
添加：
define service{
use local-service ;Name of service template to use
host_name server1
service_description MYSQL
check_command check_mysql
notifications_enabled 0
}
第 4 步：从新加载nagios服务，就可以在检测页面中看到
