Nagios的NRPE插件配置

1、NRPE簡介

  Nagios監(jiān)控遠(yuǎn)程主機(jī)的方法有多種，其方式包括SNMP、NRPE、SSH和NCSA等。這里介紹其通過NRPE監(jiān)控遠(yuǎn)程Linux主機(jī)的方式。

  NRPE（Nagios RemotePluginExecutor）是用于在遠(yuǎn)端服務(wù)器上運(yùn)行檢測命令的守護(hù)進(jìn)程，它用于讓Nagios監(jiān)控端基于安裝的方式觸發(fā)遠(yuǎn)端主機(jī)上的檢測命令，并將檢測結(jié)果輸出至監(jiān)控端。而其執(zhí)行的開銷遠(yuǎn)低于基于SSH的檢測方式，而且檢測過程并不需要遠(yuǎn)程主機(jī)上的系統(tǒng)帳號等信息，其安全性也高于SSH的檢測方式。

2、安裝配置被監(jiān)控端

1）先添加nagios用戶

# useradd -s/sbin/nologin nagios

2）NRPE依賴于nagios-plugins，因此，需要先安裝之

[root@node3 ~]# ls

nrpe-2.15.tar.gz

nagios-plugins-1.5.tar.gz

[root@node3 ~]# tar-xf nrpe-2.15.tar.gz

安裝編譯環(huán)境

[root@node3 ~]# yuminstall gcc make -y

# tar zxfnagios-plugins-1.4.15.tar.gz

# cdnagios-plugins-1.4.15

# ./configure--with-nagios-user=nagios --with-nagios-group=nagios

# make all

# make instal

3）安裝NRPE

[root@node3nrpe-2.15]# yum install openssl openssl-devel -y

# tar -zxvfnrpe-2.12.tar.gz

# cd nrpe-2.12.tar.gz

# ./configure--with-nrpe-user=nagios \

    --with-nrpe-group=nagios \

    --with-nagios-user=nagios \

    --with-nagios-group=nagios \

    --enable-command-args \

    --enable-ssl #如果要啟用ssl的話，需要安裝opensslopenssl-devel包

# make all

# make install-plugin

# make install-daemon

# makeinstall-daemon-config

4）配置NRPE

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

log_facility=daemon

pid_file=/var/run/nrpe.pid

server_address=192.168.0.3

server_port=5666

nrpe_user=nagios

nrpe_group=nagios

allowed_hosts=192.168.0.4

command_timeout=60

connection_timeout=300

debug=0

上述配置指令可以做到見名知義，因此，配置過程中根據(jù)實(shí)際需要進(jìn)行修改即可。其中，需要特定說明的是allowed_hosts指令用于定義本機(jī)所允許的監(jiān)控端的IP地址。

5）啟動NRPE

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

為了便于NRPE服務(wù)的啟動，可以將如下內(nèi)容定義為/etc/init.d/nrped腳本：

#!/bin/bash
# chkconfig: 2345 8812
# description: NRPEDAEMON
NRPE=/usr/local/nagios/bin/nrpe
NRPECONF=/usr/local/nagios/etc/nrpe.cfg
case "$1"in
start)
echo-n "Starting NRPE daemon..."
$NRPE-c $NRPECONF -d
echo" done."
;;
stop)
echo-n "Stopping NRPE daemon..."
pkill-u nagios nrpe
echo" done."
;;
restart)
$0stop
sleep2
$0start
;;
*)
echo"Usage: $0 start|stop|restart"
;;
esac
exit 0

或者，也可以在/etc/xinetd.d目錄中創(chuàng)建nrpe文件，使其成為一個基于非獨(dú)立守護(hù)進(jìn)程的服務(wù)，文件內(nèi)容如下：

service nrpe
{
flags= REUSE
socket_type= stream
wait= no
user= nagios
group= nagios
server= /usr/local/nagios/bin/nrpe
server_args= -c /etc/nagios/nrpe.cfg -i
log_on_failure+= USERID
disable= no
}

此種情況下啟動NRPE進(jìn)程需要通過重啟xinetd來實(shí)現(xiàn)。

6）配置允許遠(yuǎn)程主機(jī)監(jiān)控的對象

在被監(jiān)控端，可以通過NRPE監(jiān)控的服務(wù)或資源需要通過nrpe.cfg文件使用命令進(jìn)行定義，定義命令的語法格式為：command[<command_name>]=<command_to_execute>。比如：

command[check_rootdisk]=/usr/local/nagios/libexec/check_disk-w 20% -c 10% -p /

command[check_swap]=/usr/local/nagios/libexec/check_disk-w 40% -c 20%

command[check_sensors]=/usr/local/nagios/libexec/check_sensors #需要安裝sensor

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

command[check_load]=/usr/local/nagios/libexec/check_load-w 10,8,5 -c 20,18,15

command[check_sda1]=/usr/local/nagios/libexec/check_disk-w 20% -c 10% -p /dev/sda1

command[check_sda2]=/usr/local/nagios/libexec/check_disk-w 20% -c 10% -p /dev/sda2

command[check_zombies]=/usr/local/nagios/libexec/check_procs-w 5 -c 10 -s Z

command[check_all_procs]=/usr/local/nagios/libexec/check_procs-w 150 -c 200

7）啟動進(jìn)程

[root@node3 ~]#chkconfig --add  nrped
[root@node3 ~]#chkconfig --list nrped
nrped                 0:off        1:off        2:on        3:on        4:on        5:on        6:off
[root@node3 ~]#service nrped start
Starting NRPEdaemon...done.
[root@node3 ~]#service nrped restart
Stoping NRPEdaemon...done.
Starting NRPEdaemon...done.
[root@node3 ~]#netstat -tlnp
Active Internetconnections (only servers)
Proto Recv-Q Send-QLocal Address               ForeignAddress             State       PID/Program name 
tcp        0     0 0.0.0.0:22                 0.0.0.0:*                   LISTEN      1212/sshd         
tcp        0     0 127.0.0.1:25               0.0.0.0:*                   LISTEN      1296/master       
tcp        0     0 192.168.0.3:5666           0.0.0.0:*                   LISTEN      35058/nrpe        
tcp        0     0 :::22                      :::*                        LISTEN      1212/sshd         
tcp        0     0 ::1:25                     :::*                        LISTEN      1296/master

3、配置監(jiān)控端，nagios的服務(wù)端

1）安裝NRPE

# tar -zxvfnrpe-2.12.tar.gz

# cd nrpe-2.12.tar.gz

# ./configure--with-nrpe-user=nagios \

    --with-nrpe-group=nagios \

    --with-nagios-user=nagios \

    --with-nagios-group=nagios \

    --enable-command-args \

    --enable-ssl

# make all

# make install-plugin

2）定義如何監(jiān)控遠(yuǎn)程主機(jī)及服務(wù)：

通過NRPE監(jiān)控遠(yuǎn)程Linux主機(jī)要使用chech_nrpe插件進(jìn)行，其語法格式如下：

check_nrpe -H<host> [-n] [-u] [-p <port>] [-t <timeout>] [-c<command>] [-a <arglist...>]

測試遠(yuǎn)端主機(jī)是否正常

[root@node4 libexec]#./check_nrpe -H 192.168.0.3

NRPE v2.15

使用示例1：

定義監(jiān)控遠(yuǎn)程Linux主機(jī)swap資源的命令：

[root@node4 objects]# vim /usr/local/nagios/etc/objects/commands.cfg #添加下面的命令

definecommand{

command_namecheck_swap_nrpe

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

}

定義遠(yuǎn)程Linux主機(jī)的swap資源：

defineservice

{

usegeneric-service

host_namelinuxserver1,linuxserver2

hostgroup_namelinux-servers

service_descriptionSWAP

check_commandcheck_swap_nrpe

normal_check_interval30

}

使用示例2：

如果希望上面的command定義更具有通用性，那么上面的定義也可以修改為如下：

定義監(jiān)控遠(yuǎn)程Linux主機(jī)的命令：

definecommand

{

command_namecheck_nrpe

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

}

$USER1$/check_nrpe –H"$HOSTADDRESS$" -c $ARG1$ $ARG2$

定義遠(yuǎn)程Linux主機(jī)的swap資源：

defineservice

{

usegeneric-service

host_namelinuxserver1,linuxserver2

hostgroup_namelinux-servers

service_descriptionSWAP

check_commandcheck_nrpe!check_swap

normal_check_interval30

}

使用示例3：

如果還希望在監(jiān)控遠(yuǎn)程Linux主機(jī)時還能向其傳遞參數(shù)，則可以使用類似如下方式進(jìn)行：

定義監(jiān)控遠(yuǎn)程Linux主機(jī)disk資源的命令：

definecommand

{

command_namecheck_swap_nrpe

command_line$USER1$/check_nrpe –H "$HOSTADDRESS$" -c "check_swap" -a$ARG1$ $ARG2$

}

定義遠(yuǎn)程Linux主機(jī)的swap資源：

defineservice

{

usegeneric-service

host_namelinuxserver1,linuxserver2

hostgroup_namelinux-servers

service_descriptionSWAP

check_commandcheck_swap_nrpe!20!10

normal_check_interval30

}

實(shí)際操作：

[root@node4 objects]# vim /usr/local/nagios/etc/objects/commands.cfg #添加下面的命令
define command{
        command_name check_nrpe
        command_line $USER1$/check_nrpe -H"$HOSTADDRESS$" -c $ARG1$
       }
[root@node4 ~]# cd/usr/local/nagios/etc/objects/
[root@node4 objects]#vim commands.cfg
[root@node4 objects]#cp -p windows.cfg linuxserver.cfg
[root@node4 objects]#ll linuxserver.cfg
-rw-rw-r--. 1 nagiosnagios 4019 Feb 23 21:49 linuxserver.cfg
根據(jù)被監(jiān)控端node3的關(guān)于命令的定義來定義這個
[root@node4 objects]#vim linuxserver.cfg
define host{
        use             linux-server    ; Inherit default values from a template
        host_name       linuxserver     ; The name we're giving to this host
        alias           My linux Server ; A longer nameassociated with the host
        address         192.168.0.3     ; IP address of the host
        }
###############################################################################
###############################################################################
#
# HOST GROUPDEFINITIONS
#
###############################################################################
###############################################################################
# Define a hostgroupfor Windows machines
# All hosts that usethe windows-server template will automatically be a member of this group
#define hostgroup{
#       hostgroup_name  windows-servers ; The name of the hostgroup
#       alias           Windows Servers ; Long name of thegroup
#       }
###############################################################################
###############################################################################
#
# SERVICE DEFINITIONS
#
###############################################################################
###############################################################################
# Create a servicefor monitoring the version of NSCLient++ that is installed
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     CHECK USERS
        check_command           check_nrpe!check_users
        }
# Create a servicefor monitoring the uptime of the server
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     Load
        check_command           check_nrpe!check_load
        }
# Create a servicefor monitoring CPU load
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     SDA1
        check_command           check_nrpe!check_sda1
        }
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     SDA2
        check_command           check_nrpe!check_sda2
        }
# Create a servicefor monitoring memory usage
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     Zombie
        check_command           check_nrpe!check_zombie_procs
        }
# Create a servicefor monitoring C:\ disk usage
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     Total_procs
        check_command           check_nrpe!check_total_procs
        }
# Create a servicefor monitoring the W3SVC service
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     Swap
        check_command           check_nrpe!check_swap
        }
# Create a servicefor monitoring the Explorer.exe process
# Change thehost_name to match the name of the host you defined above
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     Rootdisk
        check_command           check_nrpe!check_rootdisk
        }
define service{
        use                     generic-service
        host_name               linuxserver
        service_description     Sensor
        check_command           check_nrpe!check_sensors

然后修改nagios.cfg，添加cfg_file一個條目

[root@node4 ~]# vim/usr/local/nagios/etc/nagios.cfg

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

檢查語法：

[root@node4 objects]#/usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

………………………….

Checking timeperiods...

Checked5 time periods.

Checking for circularpaths between hosts...

Checking for circularhost and service dependencies...

Checking global eventhandlers...

Checking obsessivecompulsive processor commands...

Checking miscsettings...

Total Warnings: 0

Total Errors:   0

然后重啟nagios服務(wù)

[root@node4 ~]# clear

[root@node4 ~]#service nagios restart

Running configurationcheck...done.

Stopping nagios:.done.

Starting nagios:done.

[root@node4 ~]#

然后進(jìn)nagios界面，就可以看到我們剛剛加入的機(jī)器，等一會就會檢查

過一段時間監(jiān)測完成以后就可以看到全是ok了