搭建 CentOS 6 服务器(15) - Cacti、Nagios

（一）Cacti
*** 需要先安装Apache + MySQL + PHP（php-snmp）

（1）安装Net-SNMP
# yum -y install net-snmp
# cp -p /etc/snmp/snmpd.conf /etc/snmp/snmpd.conf.org
# vi /etc/snmp/snmpd.conf

引用

  #       sec.name  source          community
  #com2sec notConfigUser  default       public　←注释掉
  com2sec local localhost private　←
  com2sec mynetwork 192.168.21.0/24 public　←

  #       groupName      securityModel securityName
  #group   notConfigGroup v1c           notConfigUser　←注释掉
  #group   notConfigGroup v2c           notConfigUser　←注释掉
  group MyROGroup v1 local　←
  group MyROGroup v2c local　←
  group MyROGroup v1 mynetwork　←
  group MyROGroup v2c mynetwork　←

  # Make at least  snmpwalk -v 1 localhost -c public system fast again.
  #       name           incl/excl     subtree         mask(optional)
  #view    systemview    included   .1.3.6.1.2.1.1　←注释掉
  #view    systemview    included   .1.3.6.1.2.1.25.1.1　←注释掉
  view all included .1 80　←

  # Finally, grant the group read-only access to the systemview view.

  #       group          context sec.model sec.level prefix read   write  notif
  #access  notConfigGroup ""      any       noauth    exact  systemview none none　←注释掉
  access MyROGroup "" any noauth exact all none none　←
  access MyRWGroup "" any noauth exact all all none　←

  # Check the / partition and make sure it contains at least 10 megs.
  #disk / 10000
  disk / 10000　←

# /etc/init.d/snmpd start

（2）安装RRDtool & cacti
# vi /etc/yum.repos.d/CentOS-Base.repo

引用

  [dag]
  name=Dag RPM Repository for Red Hat Enterprise Linux
  baseurl=http://ftp.riken.jp/Linux/dag/redhat/el$releasever/en/$basearch/dag/
  gpgcheck=1
  enabled=0

# wget http://dag.wieers.com/packages/RPM-GPG-KEY.dag.txt
# rpm --import RPM-GPG-KEY.dag.txt
# yum -y install --enablerepo=dag rrdtool
# yum -y install --enablerepo=dag cacti

（3）设置

创建数据库
# mysql -u root -p

引用

  mysql> create database cacti;
  mysql> GRANT ALL ON cacti.* TO cacti@localhost IDENTIFIED BY 'your-password-here';
  mysql> FLUSH privileges;
  mysql> quit;

# rpm -ql cacti | grep cacti.sql
  /usr/share/doc/cacti-0.8.8b/cacti.sql
# mysql -u cacti -p cacti < /usr/share/doc/cacti-0.8.8b/cacti.sql

设置cacti
# vi /etc/cacti/db.php

引用

  $database_type = "mysql";
  $database_default = "cacti";
  $database_hostname = "localhost";
  $database_username = "cacti";
  $database_password = "your-password-here";
  $database_port = "3306";
  $database_ssl = false;

设置Apache
# vi /etc/httpd/conf.d/cacti.conf

引用

  Alias /cacti/ /var/www/cacti/
  <Directory /var/www/cacti/>
        DirectoryIndex index.php
        Options -Indexes
        AllowOverride all
        order deny,allow
        deny from all
        allow from 127.0.0.1
        allow from 192.168.1.0/24　←
        AddType application/x-httpd-php .php
        php_flag magic_quotes_gpc on
        php_flag track_vars on
  </Directory>

# /etc/init.d/httpd restart

设置自动收集数据
# vi /etc/cron.d/cacti

引用

  */5 * * * *    cacti   /usr/bin/php /usr/share/cacti/poller.php > /dev/null 2>&1

（4）确认
http://<youripaddress>/cacti/
第一次需要按照向导设置。

（二）Nagios

被监视机器端

（1）安装nagios-plugins

# yum -y install gcc openssl openssl-devel
# mkdir /usr/local/nagios /usr/local/nagios/bin /usr/local/nagios/libexec /usr/local/nagios/etc
# useradd -d /usr/local/nagios/ -M nagios
# cd /usr/local/src
# wget http://nagios-plugins.org/download/nagios-plugins-2.0.3.tar.gz
# tar zxvf nagios-plugins-2.0.3.tar.gz
# cd nagios-plugins-2.0.3
# ./configure --prefix=/usr/local/nagios --with-nagios-user=nagios --with-nagios-group=nagios
# make
# make install

（2）安装NRPE

# cd /usr/local/src
# wget --no-check-certificate https://jaist.dl.sourceforge.net/project/nagios/nrpe-2.x/nrpe-2.15/nrpe-2.15.tar.gz
# tar zxvf nrpe-2.15.tar.gz
# cd nrpe-2.15
# ./configure
# make all
# make install
# cp -p init-script /etc/rc.d/init.d/nrpe
# chmod 755 /etc/rc.d/init.d/nrpe
# chown nagios:nagios /usr/local/nagios/etc
# cp -p sample-config/nrpe.cfg /usr/local/nagios/etc/
# vim /usr/local/nagios/etc/nrpe.cfg
　allowed_hosts=127.0.0.1,<Nagios服务器IP>
# /etc/init.d/nrpe start
# netstat -nlp | grep 5666

引用

启动nrpe：
/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

重启nrpe：
ps aux|grep nrpe
kill $pid
/usr/local/nagios/bin/nrpe -c /usr/local/nagios/etc/nrpe.cfg -d

服务器端

（1）安装Nagios

# yum -y install gd-devel
# useradd -d /usr/local/nagios/ -M nagios
# cd /usr/local/src
# wget http://jaist.dl.sourceforge.net/sourceforge/nagios/nagios-4.0.8.tar.gz -O nagios-4.0.8.tar.gz
# tar zxvf nagios-4.0.8.tar.gz
# cd nagios-4.0.8
# ./configure && make all && make fullinstall && make install-config

（2）安装NRPE

# cd /usr/local/src
# wget http://cznic.dl.sourceforge.net/project/nagios/nrpe-2.x/nrpe-2.15/nrpe-2.15.tar.gz
# tar zxvf nrpe-2.15.tar.gz
# cd nrpe-2.15
# ./configure
# make all
# make install

安装完成后，nagios的plugin里应该有一个check_nrpe：/usr/local/nagios/libexec/check_nrpe

（3）设置NRPE

# vi /usr/local/nagios/etc/objects/commands.cfg
define command{
        command_name    check_nrpe
        command_line    $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
        }
# vi /usr/local/nagios/etc/objects/localhost.cfg
define host{
        use                     linux-server            ; Name of host template to use
        host_name               Web_Server_A
        alias                   Web_Server_A
        address                 192.168.1.100
        }
define hostgroup{
        hostgroup_name  linux-servers ; The name of the hostgroup
        alias           Linux Servers ; Long name of the group
        members         Nagios_Server,Web_Server_A     ; Comma separated list of hosts that belong to this group
        }
# vi /usr/local/nagios/etc/objects/services.cfg
define service{
  use                   generic-service
  host_name             Web_Server_A
  service_description   load
  check_command         check_nrpe!check_load
  notifications_enabled 1
}

（4）服务器测试被监视服务器NRPE

# /usr/local/nagios/libexec/check_nrpe -H 192.168.1.100
NRPE v2.15
# /usr/local/nagios/libexec/check_nrpe -H 192.168.1.100 -c check_load
OK - load average: 0.02, 0.01, 0.00|load1=0.020;15.000;30.000;0; load5=0.010;10.000;25.000;0; load15=0.000;5.000;20.000;0;

（5）设置邮件通知

设置邮件内容和发送人地址

# vi /usr/local/nagios/etc/objects/commands.cfg
define command{
        command_name    notify-host-by-email
        command_line    /usr/bin/printf "%b" "***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\nHost: $HOSTNAME$\nState: $HOSTSTATE$\nAddress: $HOSTADDRESS$\nInfo: $HOSTOUTPUT$\n\nDate/Time: $LONGDATETIME$\n" | /usr/local/bin/sendEmail -f [e-mail] -t $CONTACTEMAIL$ -s mail.gmail.com -u "** $NOTIFICATIONTYPE$ Host Alert: $HOSTNAME$ is $HOSTSTATE$ **"
        }

define command{
        command_name    notify-service-by-email
        command_line    /usr/bin/printf "%b" "***** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\n\nService: $SERVICEDESC$\nHost: $HOSTALIAS$ \nAddress: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$SERVICEOUTPUT$\n" | /usr/local/bin/sendEmail -f [e-mail] -t $CONTACTEMAIL$ -s mail.gmail.com -u "** $NOTIFICATIONTYPE$ Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **"
        }

设置收件人地址

# vi /usr/local/nagios/etc/objects/contacts.cfg
define contact{
        contact_name               nagiosadmin             ; Short name of user
        use                            generic-contact        ; Inherit default values from generic-contact template (defined above)
        alias                           Nagios Admin            ; Full name of user

        email                           [e-mail]　←管理员邮件地址
  }
# service nagios restart

所有的设置内容可以放入一个新建的文件

# vi /usr/local/nagios/etc/objects/mysetting.cfg
# vi /usr/local/nagios/etc/nagios.cfg
cfg_file=/usr/local/nagios/etc/objects/mysetting.cfg

（6）使用check_linux_stats.pl监控系统运行参数

被监视机器端的默认nrpe.cfg配置文件中已经定义好了以下监控服务：check_users、check_load、check_hda1、check_zombie_procs、check_total_procs。但是有一些局限性，这里使用check_linux_stats.pl脚本扩展监控。

安装perl

# yum install -y perl-devel

安装Sys::Statistics::Linux

# cd /usr/local/src
# wget http://search.cpan.org/CPAN/authors/id/B/BL/BLOONIX/Sys-Statistics-Linux-0.66.tar.gz
# tar -zxvf Sys-Statistics-Linux-0.66.tar.gz
# cd Sys-Statistics-Linux-0.66
# perl Makefile.PL
# make
# make install

下载脚本
从https://exchange.nagios.org/directory/Plugins/Operating-Systems/Linux/check_linux_stats/details下载文件check_linux_stats.pl到/usr/local/src。

# cd /usr/local/src
# cp check_linux_stats.pl /usr/local/nagios/libexec/check_linux_stats.pl
# chown nagios:nagiso /usr/local/nagios/libexec/check_linux_stats.pl
# chmod 755 /usr/local/nagios/libexec/check_linux_stats.pl
# vi /etc/sudoers
nagios  ALL=(ALL)       NOPASSWD:/usr/local/nagios/libexec/check_linux_stats.pl

修改配置

# vi /usr/local/nagios/etc/nrpe.cfg
command[check_cpu]=/usr/local/nagios/libexec/check_linux_stats.pl -C -w 90 -c 95 -s 5
command[check_disk]=/usr/local/nagios/libexec/check_linux_stats.pl -D -w 20 -c 10 -u % -p /
command[check_load]=/usr/local/nagios/libexec/check_linux_stats.pl -L -w 10,8,5 -c 20,18,15
command[check_memory]=/usr/local/nagios/libexec/check_linux_stats.pl -M -w 90 -c 95
command[check_nginx]=/usr/local/nagios/libexec/check_linux_stats.pl -T -w 200000000 -c 300000000 -p /usr/local/nginx/logs/nginx.pid
command[check_tomcat]=sudo /usr/local/nagios/libexec/check_linux_stats.pl -T -w 5000000000 -c 7000000000 -p /var/run/tomcat.pid
# /etc/init.d/nrpe restart

监控服务器端确认

# /usr/local/nagios/libexec/check_nrpe -H 192.168.1.100 -c check_disk

被监控端常见的几个错误：

引用

CHECK_NRPE: Error - Could not complete SSL handshake.

原因：nrpe.cfg里IP限制、5666端口

引用

NRPE: Unable to read output

原因：脚本执行权限

引用

NRPE: Command 'check_tomcat' not defined

原因：nrpe.cfg里没有配置该命令