Everything IT

To delete all email in the queue from a specific email address run this command as root:

postqueue -p | tail -n +2 | awk 'BEGIN { RS = "" } /username@example\.com/ { print $1 }' | tr -d '*!' | postsuper -d -

Go to the directory and run the following command:

find . ! -newermt 2013-11-22 ! -type d -delete

Zabbix requires Apache-Mysql-PHP stack to be installed in order to run. You can follow this previous post.
Let’s download and install Zabbix

rpm -ivh http://repo.zabbix.com/zabbix/2.4/rhel/7/x86_64/zabbix-release-2.4-1.el7.noarch.rpm
yum install zabbix-server-mysql zabbix-web-mysql zabbix-agent

We have to edit timezone in /etc/httpd/conf.d/zabbix

php_value date.timezone Europe/Athens
service httpd restart

Create a database or Zabbix

mysql -u root -p
create database zabbix character set utf8;
grant all privileges on zabbix.* to 'zabbix'@'localhost' identified by 'password';
flush privileges;
exit

mysql -u zabbix -p zabbix < /usr/share/doc/zabbix-server-mysql-2.4.3/create/schema.sql
mysql -u zabbix -p zabbix < /usr/share/doc/zabbix-server-mysql-2.4.3/create/images.sql
mysql -u zabbix -p zabbix < /usr/share/doc/zabbix-server-mysql-2.4.3/create/data.sql

Edit /etc/zabbix/zabbix_server.conf to set up zabbix database credentials
Start the zabbix-server process

service zabbix-server start
systemctl enable zabbix-server.service

Finally add the necessary firewall rules for snmp and zabbix agent

firewall-cmd --permanent --add-port=161/udp
firewall-cmd --permanent --add-port=10051/tcp
firewall-cmd --reload

Windows agent
Download from:
http://www.zabbix.com/download.php
Unpack and copy to C:\
edit conf/zabbix_agentd.win.conf and add serverip under ‘Passive’ mode
Rename file to zabbix_agentd.conf
Run from command propmt in C:\install_dir –> zabbix_agentd.exe –install

Install Mysql (MariaDB) and set password

yum -y install mariadb-server mariadb
systemctl start mariadb.service
systemctl enable mariadb.service
mysql_secure_installation

Install Apache

yum -y install httpd
systemctl start httpd.service
systemctl enable httpd.service

Open ports in firewall

firewall-cmd --permanent --zone=public --add-service=http 
firewall-cmd --permanent --zone=public --add-service=https
firewall-cmd --reload

Install PHP

yum -y install php
systemctl restart httpd.service
yum -y install php-mysql
yum -y install php-gd php-ldap php-odbc php-pear php-xml php-xmlrpc php-mbstring php-snmp php-soap curl curl-devel
systemctl restart httpd.service

Now we are ready to install WordPress. Let’s create a database and a user for wordpress to work with.

mysql -u root -p
CREATE DATABASE wordpress;
CREATE USER wordpressuser@localhost IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON wordpress.* TO wordpressuser@localhost IDENTIFIED BY 'password';
FLUSH PRIVILEGES;
exit

Now let’s download and install WordPress

wget http://wordpress.org/latest.tar.gz 
tar xzvf latest.tar.gz
rsync -avP ~/wordpress/ /var/www/html/
mkdir /var/www/html/wp-content/uploads
chown -R apache:apache /var/www/html/*

Next we will configure WordPress

cd /var/www/html
cp wp-config-sample.php wp-config.php

Now we need to modify the following parameters that hold our database information in “wp-config.php” file

vim wp-config.php
// ** MySQL settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define('DB_NAME', 'wordpress');

/** MySQL database username */
define('DB_USER', 'wordpressuser');

/** MySQL database password */
define('DB_PASSWORD', 'password');

Now we can complete the WordPress installation through the web interface. In your web browser, navigate to your server’s domain name or public IP address and fill the required information.

Here I am assuming that we started with the minimal installation of Centos 7.
Let’s install some useful packages

yum install wget vim mc ntp net-tools

Now let’s configure the timezone and start the ntp service

timedatectl list-timezones | grep Athens

timedatectl set-timezone Europe/Athens

systemctl start ntpd.service

systemctl enable ntpd.service

Next we will change ssh default port. Edit ssh config file and uncomment Port putting your desired port number.

vim /etc/ssh/ssh_config

systemctl reload sshd.servive

Now let’s disable SElinux changing config file to SELINUX=disabled

vim /etc/sysconfig/selinux

Finally let’s configure firewall

systemctl status firewalld

Show configuration

firewall-cmd --permanent --list-all

Allow port

firewall-cmd --permanent --add-port=4311/tcp

Allow service

firewall-cmd --get-services
firewall-cmd --permanent --add-service=http

Remove service or port

firewall-cmd --permanent --remove-service=http
firewall-cmd --permanent --remove-port=4311/tcp

Reload and start at boot

firewall-cmd --reload
systemctl enable firewalld