1在lvs 服务器上安装nrpe客户端：
1.1，rpm方式安装nrpe客户端
下载地址：http://download.csdn.net/detail/mchdba/7493875
[root@localhost nagios]# ll
总计 768
-rw-r--r-- 1 root root 713389 12-16 12:08 nagios-plugins-1.4.11-1.x86_64.rpm
-rw-r--r-- 1 root root 32706 12-16 12:09 nrpe-2.12-1.x86_64.rpm
-rw-r--r-- 1 root root 18997 12-16 12:08 nrpe-plugin-2.12-1.x86_64.rpm
[root@localhost nagios]# rpm -ivh *.rpm --nodeps --force
1.2 在配置文件最末尾，添加配置信息以及监控主机服务器ip地址
[root@ localhost nagios]# vim /etc/nagios/nrpe.cfg
# add by tim on 2014-06-11
command[check_users]=/usr/local/nagios/libexec/check_users -w 8 -c 15
command[check_load]=/usr/local/nagios/libexec/check_load -w 15,10,5 -c 30,25,20
command[check_sda1]=/usr/local/nagios/libexec/check_disk -w 20% -c 10% -p /dev/sda
command[check_zombie_procs]=/usr/local/nagios/libexec/check_procs -w 5 -c 10 -s Z
#command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 50 -c 80
command[check_total_procs]=/usr/local/nagios/libexec/check_procs -w 750 -c 800
command[check-host-alive]=/usr/local/nagios/libexec/check_ping -H localhost -w 3000.0,80% -c 5000.0,100% -p 5
allowed_hosts = 127.0.0.1, 10.2xx.3.xx
check下命令是否生效：
[root@web-9 nrpe-2.15]# /usr/local/nagios/libexec/check_users -w 8 -c 15
USERS OK - 2 users currently logged in |users=2;8;15;0
[root@web-9 nrpe-2.15]#
看到已经USERS OK -….命令已经生效。
1.3 启动nrpe报错如下：
[root@web-9 ~]# service nrpe restart
Shutting down nrpe: [失败]
Starting nrpe: /usr/sbin/nrpe: error while loading shared libraries: libssl.so.6: cannot open shared object file: No such file or directory
[失败]
[root@web-9 ~]#
[root@db-m2-slave-1 nagios_client]# service nrpe start
Starting nrpe: /usr/sbin/nrpe: error while loading shared libraries: libssl.so.6: cannot open shared object file: No such file or directory
[失败]
[root@db-m2-slave-1 nagios_client]#
建立连接
[root@db-m2-slave-1 nagios_client]# ln -s /usr/lib64/libssl.so /usr/lib64/libssl.so.6
(如果没有libssl.so，就采用别的libssl.so.10来做软连接，ln -s /usr/lib64/libssl.so.10 /usr/lib64/libssl.so.6)
[root@db-m2-slave-1 nagios_client]#
再重新启动如下：
[root@db-m2-slave-1 nagios_client]# service nrpe start
Starting nrpe: /usr/sbin/nrpe: error while loading shared libraries: libcrypto.so.6: cannot open shared object file: No such file or directory
[失败]
[root@web-10 ~]# ll /usr/lib64/libcrypto.so
lrwxrwxrwx. 1 root root 18 10月 13 2013 /usr/lib64/libcrypto.so -> libcrypto.so.1.0.0
[root@db-m2-slave-1 nagios_client]#
再建链接：
[root@db-m2-slave-1 nagios_client]# ln -s /usr/lib64/libcrypto.so /usr/lib64/libcrypto.so.6
(或者如果没有libcrypto.so，就采用libcrypto.so.10做软连接， ln -s /usr/lib64/libcrypto.so.10 /usr/lib64/libcrypto.so.6)
[root@db-m2-slave-1 nagios_client]# service nrpe start
Starting nrpe: [确定]
[root@db-m2-slave-1 nagios_client]#
1.4 检测下nrpe是否正常运行：
去nagios服务器端check下
[root@cache-2 ~]# /usr/local/nagios/libexec/check_nrpe -H xx.xx3.xx
NRPE v2.12
[root@cache-2 ~]#
[root@cache-2 ~]# /usr/local/nagios/libexec/check_nrpe -H xx.xx3.xx
NRPE v2.12
[root@cache-2 ~]#
看到返回NRPE v2.15表示已经连接成功。
2 编写shell脚本实现lvs监控
2.1 监控脚本
Nagios里面没有现成的监控lvs的状态脚本，所以需要去网上找一个简单的监控脚本check_lvs.sh，copy到/usr/lib/nagios/plugins/目录，赋予nagios权限，脚本内容如下：
#!/bin/bash
# http://www.ohlinux.com/archives/632/
# add by tim on 20140613
USAGE_Method=\"$(basename $0)[-h|--hostname] <Free ip or hostname> [-w|--warning] <Free integer> [-c|--critical] <Free integer>\"
USAGE_Value=\"warning value must be small than critical value: `basename $0` $*\"
STATE_OK=0
STATE_WARNING=1
STATE_CRITICAL=2
STATE_UNKNOWN=3
if [ $# -lt 4 ];then
echo
echo \"Usage: $USAGE_Method\"
echo
exit 0
fi
while [ $# -gt 0 ];
do
case \"$1\" in
-w|--warning)
shift
warning=$1
;;
-c|--critical)
shift
critical=$1
;;
esac
shift
done
if [[ $warning == $critical || $warning -gt $critical ]]
then
#echo $warning
#echo $critical
echo \"$USAGE_Value\"
echo \"Usage: $USAGE_Method\"
exit 0
fi
ACT_COUNT=0
Inactive_count=0
stat1=`sudo ipvsadm | grep http | grep Route|wc -l`
if [ $stat1 -ne 0 ];then
for NUM in `sudo ipvsadm | grep http | grep Route | awk \'{print $5}\'`
do
ACT_COUNT=$(($ACT_COUNT+ $NUM))
done
for NUM in `sudo ipvsadm | grep http | grep Route | awk \'{print $6}\'`
do
Inactive_count=$(($Inactive_count+ $NUM))
done
else
echo \" stat1:$stat1, lvs critical,lvs is down now.\"
exit 3
fi
if [[ \"$ACT_COUNT\" -gt \"$critical\" ]]
then
echo \"critical - lvs connetion is : $ACT_COUNT active\"
exit 2
fi
if [[ \"$ACT_COUNT\" -gt \"$warning\" && \"$ACT_COUNT\" -lt \"$critical\" ]]
then
echo \"warning - lvs connetions is : $ACT_COUNT active\"
exit 1
fi
if [[ \"$ACT_COUNT\" -lt \"$warning\" || $ACT_COUNT == 0 ]]
then
echo \"LVS OK - LVS is running (conn: $ACT_COUNT active, $Inactive_count inactive)|active=$ACT_COUNT;69999;99999;0; inactive=$Inactive_count;69999;99999;0;\"
exit 0
fi
2.2 nrpe.cfg里面配置如下
Vim /etc/nagios/nrpe.cfg，在里面添加一行check_lvs命令：
command[check_lvs]=/usr/lib/nagios/plugins/check_lvs -w 300 -c 600
之后重启nrpe
[root@/root/nagios/check_lvs ~]# service nrpe restart;
Shutting down nrpe: [确定]
Starting nrpe: [确定]
[root@/root/nagios/check_lvs ~]#service nrpe restart;
2.3 去nagios服务端check一下
[root@cache-2 ~]# /usr/local/nagios/libexec/check_nrpe -H 1x.xx4.x.x5 -c check_lvs
lvs critical,lvs is down now.
[root@cache-2 ~]#
看到check出来lvs服务已经处于down模式。
说明：由于check_lvs是要调用ipvsadm命令来获取LVS状态的，而ipvsadm命令是只能以root用户来运行的, 所以需要将nagios用户设置成可以无需密码直接su成root，这样就能以nagios用户运行命令sudo /usr/lib/nagios/plugins/check_lvs 。在centos系统中，无法直接调用sudo命令，需要修改/etc/sudoers, 找到 #Defaults requiretty 并取消注释，另外新增一行。表示nagios用户不需要登陆终端就可以调用命令，如下所示：
Defaults requiretty
Defaults:nagios !requiretty
#添加nagios 请求sudo，允许特定指令时（可跟参数），不需要密码（如）。
nagios ALL=(ALL) NOPASSWD: ALL
再去naigos服务器上面check下，已经生效，如下所示：
[root@cache-2 etc]# /usr/local/nagios/libexec/check_nrpe -H 10.xx.xx.xx -c check_lvs
LVS OK - LVS is running (conn: 16 active, 77 inactive)|active=16;69999;99999;0; inactive=77;69999;99999;0;
[root@cache-2 etc]#
2.4 在nagios服务器上添加配置
vim services.cfg
define service{
host_name lvs-lan
service_description Check lvs
check_command check_nrpe!check_lvs
max_check_attempts 5
normal_check_interval 3
retry_check_interval 2
check_period 24x7
notification_interval 10
notification_period 24x7
notification_options w,c,r
contact_groups opsweb
}
vim objects/commands.cfg
define command{
command_name check_lvs
command_line $USER1$/check_lvs -H $HOSTADDRESS$ -w $ARG1$ -c $ARG2$
}
之后重新加载nagios既完成了对lvs的监控服务。
[root@cache-2 etc]# service nagios reload
Running configuration check...
Reloading nagios configuration...
done
[root@cache-2 etc]#
至此，nagios下面对lvs服务的监控已经完成。
参考资料：http://c20031776.blog.163.com/blog/static/684716252013627506890/