Nagios之事件处理

目标：实现在监控3306端口服务时,出现1次critical软状态时或者在上一次执行后没有成功后出现的第一次硬状态critical情况下，远程执行mysql重启服务,并且每次执行远程重启服务前把报告事件记录到DB中

牵涉技术：

(1)Nagios事件处理原理

(2)Ssh无密码登录执行命令

(3)Perl操作mysql

如果大家对以上三条都掌握了，相信看懂这篇文章也就不成话下了。

##进入正题##

前期准备工作

I.制作ssh无密码登录

实现目标：nagios用户无密码登录server

大家对root用户无密码登录都做过。但是今天，我要做的是普通用户nagios用户无密码登录（在此感谢我同事的技术支持）.

角色

Host_ip

备注

Client

192.168.x.x

Nagios监控端作为Client，目的是为了远程执行脚本

Server

192.168.x.y

存启动服务脚本，如：mysql脚本

Client端(192.168.x.x)制作

---------------------------------------------------------------------------------------------------

(1)     创建nagios用户略过(Server端也需要)

(2)     su –nagios环境下执行

ssh-keygen -t rsa

一路回车便可，无需密码。

(3)将公钥copy到server端nagios家目录下

[nagios@nagios ~]$ scp .ssh/id_rsa.pub nagios@192.168.x.y:/home/nagios/

The authenticity of host '192.168.x.y (192.168.x.y)' can't be established.

RSA key fingerprint is 66:9a:b5:86:3d:81:22:9b:f8:67:9e:af:aa:4c:4a:97.

Are you sure you want to continue connecting (yes/no)? yes

Warning: Permanently added '192.168.x.y' (RSA) to the list of known hosts.

nagios@192.168.x.y's password:

id_rsa.pub                                                                                 100%  411     0.4KB/s   00:00

---------------------------------------------------------------------------------------------------

Server端(192.168.x.x)制作

--------------------------------------------------------------------------------------------------

(1)     进入server端,登入nagios帐号

(2)     创建mkdir /home/nagios/.ssh

(3)     将公钥匙写入authorized_keys文件:

 cat /home/nagios/id_rsa.pub >>.ssh/authorized_keys

(4)     改权限(以root身份或者通过visudo授权给nagios):

chmod 700 /home/nagios/.ssh

chmod 600 /home/nagios/.ssh/authorized_keys

检查

SERVER端权限检查

[root@centos-server nagios]# ls -la /home/nagios|grep .ssh

drwx------- 2 nagios nagios 4096 Aug  3 09:04 .ssh

[root@centos-server nagios]# ls -la /home/nagios/.ssh/

total 12

drw------- 2 nagios nagios 4096 Aug  3 09:04 .

drwx------ 4 nagios nagios 4096 Aug  3 09:03 ..

-rw------- 1 nagios nagios  411 Aug  3 09:04 authorized_keys

请确保红色标识的内容(保证.ssh目录的权限为700, authorized_keys的权限为600)

nagios用户持有者

CLIENT端登录测试

[nagios@nagios ~]$ ssh nagios@192.168.x.y

Last login: Wed Aug  3 09:15:59 2011 from 192.168.x.x

[nagios@centos-server ~]$

看到没？从192.168.x.x登录到192.168.x.y无需密码了。

如果没有这样的效果，大家看下是不是前面的权限问题。我曾今也是因为权限折腾了我同事半天。哈哈。

II.无密码登录远程执行命令

  实现目标：nagios用户远程启动server端mysql服务

-----------------------------------------------------------------------------------------------

Server端(192.168.x.x)制作

------------------------------------------------------------------------------------------------

(1)     配置mysql启动控制脚本

输入以下SQL语句，创建一个具有root权限的用户（admin）和密码（controlmysql）：

GRANT ALL PRIVILEGES ON *.* TO 'admin'@'localhost' IDENTIFIED BY ' controlmysql ';

GRANT ALL PRIVILEGES ON *.* TO 'admin'@'127.0.0.1' IDENTIFIED BY ' controlmysql ';

作用：用与启动/关闭控制mysql服务

Mysql控制(启动/停止等)脚本

#!/bin/sh

mysql_port=3306

mysql_username="admin"

mysql_password=" controlmysql "

mysql_scripts_path="/data0/mysql/3306"

mysqld_path="/usr/local/webserver/mysql"

start_mysql()

{

    printf "Starting MySQL.../n"

    /bin/sh ${mysqld_path}/bin/mysqld_safe --defaults-file=/data0/mysql/${mysql_port}/my.cnf 2>&1 > /dev/null &

}

stop_mysql()

{

    printf "Stoping MySQL.../n"

    ${mysqld_path}/bin/mysqladmin -u ${mysql_username} -p${mysql_password} -S /tmp/mysql.sock shutdown

}

restart_mysql()

{

    printf "Restarting MySQL.../n"

    stop_mysql

    sleep 5

    start_mysql

}

kill_mysql()

{

    kill -9 $(ps -ef | grep 'bin/mysqld_safe' | grep -v 'grep'| awk '{printf $2}')

    kill -9 $(ps -ef | grep 'libexec/mysqld' | grep -v 'grep' |awk '{printf $2}')

}

if [ "$1" = "start" ]; then

    start_mysql

elif [ "$1" = "stop" ]; then

    stop_mysql

elif [ "$1" = "restart" ]; then

    restart_mysql

elif [ "$1" = "kill" ]; then

    kill_mysql

else

    printf "Usage: ${mysql_scripts_path}/mysql {start|stop|restart|kill}/n"

fi

(2)     配置sudo，允许nagios用户执行脚本

**如果没有sudo，yum –y install sudo**

#visudo

添加

nagios ALL=(root) NOPASSWD:/data0/mysql/3306/mysql start

检查

SERVER端脚本测试检查

[root@centos-server ~]# netstat -an|grep 3306

[root@centos-server ~]#

说明mysql没有起来

[root@centos-server ~]# /data0/mysql/3306/mysql start

Starting MySQL...

[root@centos-server ~]# netstat -an|grep 3306

tcp        0      0 :::3306                     :::*                        LISTEN    

[root@centos-server ~]#

脚本OK，正常

Client端测试(以nagios用户登录)

[nagios@nagios ~]$ ssh nagios@192.168.x.y "sudo /data0/mysql/3306/mysql start"

sudo: sorry, you must have a tty to run sudo

解决：

Server端修改visudo，将下面一行注释

Defaults    requiretty

再试

[nagios@nagios ~]$ ssh nagios@192.168.x.y "sudo /data0/mysql/3306/mysql start"

Starting MySQL...

正常启动

检查SERVER端 端口3306是否存在

恭喜，基本功已经做完。我们可以去玩监控端nagios配置了

III.Nagios监控端配置

(1)nagios基本配置文件如下：

mfs_hosts.cfg

define host{

        use                     mfs-server    

        host_name               mfs-192.168.x.y

        alias                   mfs-192.168.x.y

        address                 192.168.x.y

        }

mfs_hostgroups.cfg

define hostgroup{

        hostgroup_name  mfs-servers

        alias           Mfs Linux Servers

        members        mfs-192.168.x.y

        }

mfs_services.cfg

define service {

        name                    mfs-services

        service_description     checkport

        check_command           check_tcp!3306

        check_period            24x7

        max_check_attempts      2

        normal_check_interval   3

        retry_check_interval    1

        notification_interval   5

        notification_period     24x7

        notification_options    w,u,c,r

        register                   0

}

define service{

        use                             mfs-services

        host_name                       mfs-192.168.x.y

        event_handler_enabled   1

        event_handler          restart_mysql

 }

define service{

        use                             mfs-service

        host_name                       mfs-192.168.x.y

        service_description             PING

        check_command                   check_ping!100.0,20%!500.0,60%

        }

commands.cfg

define command{

        command_name    restart_mysql

        command_line    /usr/local/nagios/libexec/restart_mysql $SERVICESTATE$ $SERVICESTATETYPE$ $SERVICEATTEMPT$  $HOSTADDR

ESS$

}

(2)改写/usr/local/nagios/libexec/restart_mysql

restart_mysql

HostAddress=$4

debug=1

if [ $debug -eq 1 ];then

echo "MysqlServer:${HostAddress}" >>/tmp/ReMysql.log

fi

case "$1" in

OK)

        ;;

WARNING)

        ;;

UNKNOWN)

        ;;

CRITICAL)

        case "$2" in

        SOFT)

                case "$3" in

                1)

                      if [ $debug -eq 1 ];then

                        echo  "Restarting Mysql service (1rd soft critical state)..." >>/tmp/ReMysql.log

                      fi

                        /usr/bin/ssh nagios@${HostAddress} "sudo /data0/mysql/3306/mysql start"

                        ;;

                        esac

                ;;

        HARD)

         if [ $debug -eq 1 ];then

                echo  "Restarting Mysql service..." >>/tmp/ReMysql.log

         fi

                 /usr/bin/ssh nagios@${HostAddress} "sudo /data0/mysql/3306/mysql start"

                ;;

        esac

        ;;

esac

exit 0

注明：测试最好将debug设置为1

申明：本脚本暂时的作用是远程重启mysql，后续还要添加写入数据库的脚本。

检查

Nagios配置文件检查

/usr/local/nagios/bin/nagios –v /usr/local/nagios/etc/nagios.cfg

无错误,重启nagios

Service nagios restart

被监控端开启mysql等相关服务，保证监控一切正常!如图：

尝试正常关闭mysql服务

实现目标：当出现第一次软状态的critical情况下，去尝试重启mysql.

以下4条信息足以证明我们想达到的效果已经实现!

(1)检查监控端nagios图

(2)检查监控端脚本日志

[root@nagios tmp]# tail -f ReMysql.log

MysqlServer:192.168.x.y

Restarting Mysql service (1rd soft critical state)...

(3)被监控端检查端口是否存在

[root@centos-server ~]# netstat -an|grep 3306

tcp        0      0 :::3306                     :::*                        LISTEN

(4)再检查监控端nagios图

注明：到这里我们已经实现了第一个想法，就是远程重启服务。下面，我们要实现将事件记录到mysql中。

=======================================================

IV将通知信息写入Mysql

实现目标：将nagios报错信息写入到mysql DB中

角色

Host_ip

备注

Client

192.168.x.x

Nagios监控端作为Client，执行将报错信息写入数据库脚本

DB Server

192.168.x.z

存储报错信息的DB

DB Server端操作：

-----------------------------------------------------------------------------------------------

(1)创建库

create database nagios;

(2)授权

输入以下SQL语句，创建一个具有插入/修改/删除/浏览权限的用户（nagioslog）和密码（nagioslog）（允许nagios监控端远程登录）：

GRANT ALL PRIVILEGES ON nagios.* TO 'nagioslog'@'192.168.x.x' IDENTIFIED BY '12345678';

作用：用与插入/修改/删除/浏览数据

(3)以nagioslog用户登录创建log表

create table log(host_ip varchar(50),services_desc varchar(200),plugin_out varchar(500)) ENGINE=MyISAM   DEFAULT   CHARSET=utf8;

Client端操作

-----------------------------------------------------------------------------------------

(1)安装perl操作mysql环境

 perl -MCPAN -e "install DBI"

perl -MCPAN -e "install DBD::mysql"

(2)操作mysql脚本

Perl远程操作mysql脚本

#!/bin/perl

#Last Modifed by Hahazhu 2011/08/03

use DBI;

##########INIT DEFINED###########

my $remote_mysql="192.168.x.z";

my $remote_db="nagios";

my $remote_mysql_user="nagioslog";

my $remote_mysql_pwd="12345678";

my $debug=1;

##########Recevice Values#########

my $host_ip=$ARGV[0];

my $service_desc=$ARGV[1];

my $plugin_out=$ARGV[2];

my $dbh = DBI->connect("DBI:mysql:database=$remote_db;host=$remote_mysql", "$remote_mysql_user", "$remote_mysql_pwd", {'RaiseError'

=> 1});

my $rows = $dbh->do("INSERT INTO log (host_ip, services_desc, plugin_out) VALUES ('$host_ip', '$service_desc', '$plugin_out')");

if ($debug){

    print "$rows row(s) affected /n";

}

if($debug){

my $sth = $dbh->prepare("SELECT host_ip, services_desc , plugin_out FROM log");

$sth->execute();

    while (@data=$sth->fetchrow_array()){

        print "$data[0] $data[1] $data[2]/n";

    }

}

$dbh->disconnect();

申明：测试前请将$debug设置为1.

检查

Nagios端以nagios用户执行插入数据脚本

[nagios@nagios libexec]$ perl insert_log_to_mysql.pl 1.1.1.1 check_3306 "connection refused"

1 row(s) affected

1.1.1.1    check_3306 connection refused

DB Server端检查

mysql> select * from log;

+---------+---------------+--------------------+

| host_ip | services_desc | plugin_out         |

+---------+---------------+--------------------+

| 1.1.1.1 | check_3306    | connection refused |

+---------+---------------+--------------------+

1 row in set (0.00 sec)

OK，脚本测试无问题。后面的工作就是将其加入到nagios配置里了。

V.Nagios服务配置调整

Commands.cfg

define command{

        command_name    restart_mysql

        command_line    /usr/local/nagios/libexec/restart_mysql $SERVICESTATE$ $SERVICESTATETYPE$ $SERVICEATTEMPT$  $HOSTADDRESS$ $SERVICEDESC$ "$SERVICEOUTPUT$"

}

启动mysql脚本要调整restart_mysql

#/bin/sh

HostAddress=$4

Services_desc=$5

Plugin_out=$6

debug=1

if [ $debug -eq 1 ];then

echo "MysqlServer:${HostAddress}" >>/tmp/ReMysql.log

fi

case "$1" in

OK)

        ;;

WARNING)

        ;;

UNKNOWN)

        ;;

CRITICAL)

        case "$2" in

        SOFT)

                case "$3" in

                1)

                      if [ $debug -eq 1 ];then

                        echo  "Restarting Mysql service (1rd soft critical state)..." >>/tmp/ReMysql.log

                      fi

                        /usr/bin/perl /usr/local/nagios/libexec/insert_log_to_mysql.pl ${HostAddress} ${Services_desc} ${Plugin_out}

                        /usr/bin/ssh nagios@${HostAddress} "sudo /data0/mysql/3306/mysql start"

                        ;;

                        esac

                ;;

        HARD)

         if [ $debug -eq 1 ];then

                echo  "Restarting Mysql service..." >>/tmp/ReMysql.log

         fi

                 /usr/bin/perl /usr/local/nagios/libexec/insert_log_to_mysql.pl ${HostAddress} ${Services_desc} “${Plugin_out}”

                 /usr/bin/ssh nagios@${HostAddress} "sudo /data0/mysql/3306/mysql start"

                ;;

        esac

        ;;

esac

exit 0

申明：调试前最好把debug设置为1

检查

到了本文最后一部分了，有点激动…

看看，我们验证能不能达到我们下面的目标.

实现目标：

重启mysql服务，必把相关日志记录到另一台mysql DB中。

试验：stop mysql服务

Nagios端检查图：

Nagios端日志:

[root@nagios ~]# tail -f /tmp/ReMysql.log

MysqlServer:192.168.x.y

Restarting Mysql service (1rd soft critical state)...

此时检查mysql服务端

[root@centos-server ~]# netstat -an|grep 3306

tcp        0      0 :::3306                     :::*                        LISTEN 

再检查记录日志情况：

mysql> select * from nagios.log;

+--------------+---------------+--------------------+

| host_ip      | services_desc | plugin_out         |

+--------------+---------------+--------------------+

| 192.168.x.y | checkport     | Connection refused |

+--------------+---------------+--------------------+

1 row in set (0.00 sec)

OK，目标已经实现。不仅实现了远程开机。而且将错误记录下来了。

到此，本文结束。我相信大家会有更多的想法去扩展…

下一篇，我将会带大家学习下nagios 分布式监控!

本文出自 “坏男孩” 博客