Nagios 3.x Server-Client 安裝筆記!－雜七雜八的小筆記!

一、名詞定義與必要packages：

(1) Server為Monitoring Host
- $ yum install -y httpd php gcc glibc glibc-common \
gd gd-devel openssl openssl-devel

- nagios-3.4.1.tar.gz (Nagios Core)
- nagios-plugins-1.4.15.tar.gz (Nagios plugins)
- nrpe-2.13.tar.gz (NRPE)

(2) Client為Remote Host
- $ yum install -y httpd php gcc glibc glibc-common \
gd gd-devel openssl openssl-devel xinetd

- nagios-plugins-1.4.15.tar.gz (Nagios plugins)
- nrpe-2.13.tar.gz (NRPE)

二、重要設定、目錄結構與注意事項：

(1) Server目錄結構與設定：

- 安裝完nagios後，目錄會落在 /usr/local/nagios

- nagios自己的偵測工具目錄落在 /usr/local/nagios/libexec
如：/usr/local/nagios/libexec/check_disk -w 20% -c 10% /
(觀看自己Root space下的空間，若剩餘20%空間就發"WARNING"
若剩餘10%空間就發"CRITICAL")

- 要監控哪些機器的設定檔皆位在 /usr/local/nagios/etc/objects
(localhost.cfg 裡有範例檔，可以參考它來設定)

- 定義nagios自己設定檔要使用的commands，
請在此檔案修改：/usr/local/nagios/etc/objects/commands.cfg

(2) Client目錄結構與設定：

- 安裝完nagios-plugins後，目錄也是落在 /usr/local/nagios

- nagios自己的偵測工具目錄也是落在 /usr/local/nagios/libexec

- Client端主要的NRPE設定檔位於：/usr/local/nagios/etc/nrpe.cfg
如：command[check_root_space]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /
(定義Client端的NRPE本機端的指令，用在cfg檔裡"check_command"。
此例子指令名稱為"check_root_space"，
指令功用為"/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /")

三、cfg檔設定實例

用途與說明：我們要使用Server去撈出Client的Root space(/)，那就要藉由Server端的Nagios去跟Client端的NRPE要Client資訊(Root space)。

step 1. (Server)

$ vim /usr/local/nagios/etc/nagios.cfg

--------------------------------加入-----------------------------------
cfg_file=/usr/local/nagios/etc/objects/samplehost.cfg
------------------------------------------------------------------------
此samplehost.cfg的設定我們會在step 4說明

※若要指定目錄，可以使用cfg_dir

step 2. (Client)

$ vim /usr/local/nagios/etc/nrpe.cfg

--------------------------------加入-----------------------------------
command[check_root_space]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /
------------------------------------------------------------------------
此"check_root_space"指令定義，我們會在step 4的"check command"使用

step 3. (Server)

$ vim /usr/local/nagios/etc/objects/commands.cfg

--------------------------------加入-----------------------------------
define command{
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}
------------------------------------------------------------------------
此"check_nrpe"指令定義，我們會在step 4的"check command"使用

step 4. (Server)

$ vim /usr/local/nagios/etc/objects/samplehost.cfg

--------------------------------加入-----------------------------------
define hostgroup {
hostgroup_name myGroup1
alias Linux Servers
members sampleHost
}

define host {
use linux-server
host_name sampleHost
alias sampleHost
address 192.168.1.2
hostgroups MyGroup1
}

define service {
use generic-service
host_name sampleHost
service_description Root Partition
check_command check_nrpe!check_root_space
}
------------------------------------------------------------------------