Configuring multiple websites with ease using Apache

When using Apache to host websites, developers tend to either have one configuration file with multiple sites defined within in it (often /etc/httpd/httpd.conf or similar), or end up dealing with a swarm of separate files in /etc/apache2/sites-available – one per domain.

If all the domains are identical, in terms of file structure – apart from the hostname – then we can use Apache’s mod_vhost_alias module to simplify the configuration. When combined with mod_rewrite and use of some Apache environment variables (e.g. %{HTTP_HOST}), your configuration can become much more manageable.

So, you can go from multiple virtual hosts configured similar to the below – where all that’s changing between site(s) is effectively the hostname – :

<Virtualhost *:80>
    ServerName mydomain.com
    ServerAlias www.mydomain.com
    DocumentRoot /var/www/vhosts/mydomain.com/public/
    <Location '/'>
         Allow from ALL
         AllowOverRide ALL
    </Location>

    CustomLog /var/log/apache2/mydomain.com-access.log combined
    ErrorLog /var/log/apache2/error.log
</VirtualHost>

To :

<VirtualHost *:80>
    UseCanonicalName Off
    VirtualDocumentRoot /var/www/vhosts/%0/public/
    <Location '/'>
        Allow from ALL
        AllowOverRide ALL
    </Location>
    CustomLog /var/log/apache2/%{HTTP_HOST}-access.log combined
    ErrorLog /var/log/apache2/error.log
</VirtualHost>

Advantages:

1. Once the directory structure has been created (and DNS configured) sites can be served immediately
2. No need to restart Apache,
3. No need to create a new configuration file (one per site etc)

Disadvantages:

1. Perhaps difficult to handle e.g. www.mydomain.com and mydomain.com being hosted from the same directory (leading to symlinks in e.g. /var/www/vhosts).
2. Have to rely on .htaccess files for per-site configuration (which may not be desirable ).