监控之--Nagios如何监控本地主机及本地服务

上一节内容介绍了Nagios监控服务在linux环境下的安装过程，本节内容将详细介绍如何使用已经安装的Nagios服务的一些配置文件的使用以及如何监控本地相关服务，如要完成对一台主机的监控Nagios作为主程序是必不可少的，但是仅仅只要nagios也是完成不了的，以下内容简单介绍下nagios的主配置文件和对本地主机的监控
Nagios监控看那个角色配置：
监控端和被监控端的收据收集（C/S架构），监控端和用户（B/S架构）之间的数据呈现

Nagios主程序，插件包，nrpe等相关插件

一、配置文件检查
1.1 查看nagios主目录相关功能

[root@XueGod63Nagios]# ll /usr/local/nagios/
bin             #Nagios执行程序所在目录
etc             #nagios配置文件坐在目录，初始安装只有几个*.cfg文件俺
libexec         #监控所用命令，需要安装了nagios-plugins插件了才会有，检测命令，不装是空的
sbin            #Nagios的Cgi文件所在目录，外部命令所需要的文件存放目录
share           #Nagios前端页面
var             #日志文件，pid文件等

1.2 检查配置文件是否存在错误

[root@node1 ~]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
……………………
……………………
Checking obsessive compulsive processor commands...
Checking misc settings...
Total Warnings: 0
Total Errors:   0

配置文件无异常，警告0，错误0
1.3 指定配置文件以守护进程的方式启动

[root@node1 ~]# /usr/local/nagios/bin/nagios -d /usr/local/nagios/etc/nagios.cfg

1.4 nagios.conf主要配置内容

[root@node1 ~]# cat /usr/local/nagios/etc/nagios.cfg  | grep -E -v "^#|^$"
log_file=/usr/local/nagios/var/nagios.log                #日志位置
cfg_file=/usr/local/nagios/etc/objects/commands.cfg      #命令文件位置
cfg_file=/usr/local/nagios/etc/objects/contacts.cfg      #定义联系人
cfg_file=/usr/local/nagios/etc/objects/timeperiods.cfg   #定义时间段
cfg_file=/usr/local/nagios/etc/objects/templates.cfg     #定义模板(联系人主机模板)
cfg_file=/usr/local/nagios/etc/objects/linehost.cfg      #监控远程主机相关配置(监控远程主机添加的配置文件)
cfg_file=/usr/local/nagios/etc/objects/localhost.cfg     #监控本机相关配置
object_cache_file=/usr/local/nagios/var/objects.cache    #
precached_object_file=/usr/local/nagios/var/objects.precache
resource_file=/usr/local/nagios/etc/resource.cfg         #资源变量配置文件，包括$USER1$变量（一个路径）
status_file=/usr/local/nagios/var/status.dat
status_update_interval=10                                #状态更新时间，单位s
nagios_user=nagios                                       #指定守护进程运行用户
nagios_group=nagios                                      #指定进程运行用户组
check_external_commands=1                                #命令检查
command_check_interval=-1
command_file=/usr/local/nagios/var/rw/nagios.cmd
external_command_buffer_slots=4096
lock_file=/usr/local/nagios/var/nagios.lock
temp_file=/usr/local/nagios/var/nagios.tmp
temp_path=/tmp
event_broker_options=-1
log_rotation_method=d                                    #日志滚动，默认天
log_archive_path=/usr/local/nagios/var/archives
sleep_time=0.25
service_check_timeout=60                                   #服务器检查超时时间
host_check_timeout=30
event_handler_timeout=30
notification_timeout=30
ocsp_timeout=5
perfdata_timeout=5

[root@node1 ~]# ls /usr/local/nagios/etc/cgi.cfg                  #cgi配置文件，优先级高于nagios.cfg
[root@node1 ~]# cat /usr/local/nagios/etc/cgi.cfg | grep -E -v '^#|^$'
main_config_file=/usr/local/nagios/etc/nagios.cfg               #指定Nagios的配置文件位置
physical_html_path=/usr/local/nagios/share                      #指定web访问的物理路径
url_html_path=/nagios                                           #在url后加nagios方能访问
show_context_help=0                                             #
use_pending_states=1
use_authentication=1                                            #使用认证功能
use_ssl_authentication=0

authorized_for_system_information=nagiosadmin,admin             #认证用户
…………

二、Nagios监控服务的健康状态
2.1 监控本地NFS服务状态

[root@node1 ~]# cd /usr/local/nagios/etc/objects/
[root@node1 objects]# cp localhost.cfg localhost.cfg.bak

在文件末尾添加以下内容
define service{
use                             local-service         ; Name of service template to use
host_name                       localhost
service_description             NFS
check_command                   check_tcp!2049
notifications_enabled           0
}
配置nagios.cfg主配置文件
[root@node1 objects]# vim /usr/local/nagios/etc/nagios.cfg
cfg_file=/usr/local/nagios/etc/objects/localhost.cfg

安装和启动NFS服务器

[root@node1 objects]# mkdir /nfs
[root@node1 objects]# vim /etc/exports
/nfs *(rw)
[root@node1 objects]# /etc/init.d/nfs restart
验证nfs
[root@node1 objects]# showmount -e 192.168.31.101
Export list for 192.168.31.101:
/nfs *

检查localhost是否已经正常启用，检查nagios配置文件，如无错误，则重启nagios服务

[root@node1 objects]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
[root@node1 objects]# service nagios restart

验证

[root@node1 objects]# service nfs stop
[root@node1 objects]# service nfs restart

2.2 Nagios远程监控Mysql数据库状态
安装mysql服务器
[root@node1 ~]# yum -y install mysql mysql-server mysql-devel
[root@node1 ~]# service mysqld restart
[root@node1 ~]# chkconfig mysqld on
创建测试数据库

mysql> create database nagiostest;
mysql> grant select on nagiostest.* to nagiostest@"localhost";
mysql> flush privileges;

测试

[root@node1 objects]# /usr/local/nagios/libexec/check_mysql -H 127.0.0.1 -u nagiostest -d nagiostest
Uptime: 438  Threads: 2  Questions: 11  Slow queries: 0  Opens: 15  Flush tables: 1  Open tables: 8  Queries per second avg: 0.25|Connections=4c;;; Open_files=16;;; Open_tables=8;;; Qcache_free_memory=0;;; Qcache_hits=0c;;; Qcache_inserts=0c;;; Qcache_lowmem_prunes=0c;;; Qcache_not_cached=0c;;; Qcache_queries_in_cache=0;;; Queries=11c;;; Questions=11c;;; Table_locks_waited=0c;;; Threads_connected=2;;; Threads_running=1;;; Uptime=438c;;;
[root@node1 objects]#

命令添加（添加的command_name必须在/usr/local/nagios/libexec/该文件夹下存在）

[root@node1 objects]# vim commands.cfg
define command{
command_name    check_mysql
command_line    $USER1$/check_mysql -H $HOSTADDRESS$ -u nagiostest -d nagiostest
}
[root@node1 objects]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

无报错和警告则重启nagios服务
测试：关闭msyqld服务

[root@node1 libexec]# service mysqld stop

2.3监控远程主机mysql服务及其他服务

[root@node1 objects]# vim ../nagios.cfg
新增配置监控配置文件及服务
cfg_file=/usr/local/nagios/etc/objects/remodehost.cfg
cfg_file=/usr/local/nagios/etc/objects/services.cfg
define host{
use             linux-server
host_name       node2.cn
alias           MySQL-Serve
address         192.168.31.102
icon_image      server.gif
statusmap_image server.gd2
2d_coords       500,200
3d_coords       500,200,100
}

添加监控的服务，可参考localhost.cfg配置文件相关服务配置方式进行配置

[root@node1 objects]# vim services.cfg
define service{
use                     local-service
host_name               node2.cn
service_groups          MysqlGroup
service_description     MySqlSev
check_command           check_mysql
}
define service{
use                             local-service         ; Name of service template to u
se
host_name                       node2.cn
service_description             PING
check_command                   check_ping!100.0,20%!500.0,60%
}
define service{
use                             local-service         ; Name of service template to u
se
host_name                       node2.cn
service_description             Root Partition
check_command                   check_local_disk!20%!10%!/
}
…………
define servicegroup{
servicegroup_name       MysqlGroup
alias                   MySQLServer
members                 node2.cn,MySqlSev
}

检查配置文件无错误和警告信息则重启服务

[root@node1 objects]# /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
[root@node1 objects]# service nagios restart

通过浏览器查看web端监控主机情况