= Multi Site WordPress =
This article describes what I did to set up a multi site Wordpress system running CentOS 7 using the RPM's available from EPEL.
{{{
yum install httpd wordpress mariadb-server
systemctl enable mariadb
systemctl enable httpd
}}}

Initiate and harden mariadb
{{{
mysql_secure_installation
}}}
For production system it's best to say yes to all options except off course the password.

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


Edit /etc/wordpress/wp-settings.php and include new salts generated here: https://api.wordpress.org/secret-key/1.1/salt/

Put in the following snippet before /* That's all, stop editing! Happy blogging. */
{{{
define( 'WP_ALLOW_MULTISITE', true );
define('MULTISITE', true);
define('SUBDOMAIN_INSTALL', true);
define('DOMAIN_CURRENT_SITE', 'dev.jorritsma.cc');
define('PATH_CURRENT_SITE', '/');
define('SITE_ID_CURRENT_SITE', 1);
define('BLOG_ID_CURRENT_SITE', 1);
define('COOKIE_DOMAIN', $_SERVER['HTTP_HOST']);
}}}

Edit the WordPress configuration for Apache in /etc/httpd/conf.d/wordpress:
{{{
<VirtualHost *:80>
  ServerName dev.jorritsma.cc # network host
  #LogLevel debug

  DocumentRoot /usr/share/wordpress
  <Directory /usr/share/wordpress>
    AllowOverride Options
    <IfModule mod_authz_core.c>
      # Apache 2.4
      #Require local
      Require all granted
    </IfModule>
   <IfModule mod_rewrite.c>
     # add a trailing slash to /wp-admin
     RewriteRule ^wp-admin$ wp-admin/ [R=301,L]
     RewriteCond %{REQUEST_FILENAME} -f [OR]
     RewriteCond %{REQUEST_FILENAME} -d
     RewriteRule ^ - [L]
     RewriteRule ^(wp-(content|admin|includes).*) $1 [L]
     RewriteRule ^(.*\.php)$ $1 [L]
     RewriteRule . index.php [L]
   </IfModule>
  </Directory>

  <Directory /usr/share/wordpress/wp-content/plugins/akismet>
    <FilesMatch "\.(php|txt)$">
      Order Deny,Allow
      Deny from all
    </FilesMatch>
  </Directory>

  # stop the xmlrpc spam / ddos
  <Files "xmlrpc.php">
    Order Deny,Allow
    Deny from all
  </Files>

  <Directory /usr/share/wordpress/wp-admin>
    <IfModule mod_authz_core.c>
      # Apache 2.4
      Require local
      #Require ip 83.162.221.129
      Require all granted
    </IfModule>
  </Directory>
</VirtualHost>
}}}

== SSL certificates ==
It's nowadays easy to get valid SSL certificates if you chose for letsencrypt.org certificates.
The certificates are free, and renewal can be fully automated.

{{{
yum install certbot-apache
}}}