Nagios之事件处理
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
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