Apache Web Server Administration Cheat Sheet for Linux

A few quick tips and a cheat sheet for Apache web server administration on a Linux based server. Restart services and setup virtual hosts.

Restart Apache on Linux

You can restart the Apache web server by entering the following command:

sudo /etc/init.d/apache2 restart

Change the Apache DocumentRoot

Website configs are stored within /etc/apache2/sites-available/ and a symbolic link is created within /etc/apache2/sites-enabled. Generally, you store all your website configs in sites-available and create/remove links in sites-enabled as required.

sudo pico /etc/apache2/sites-available/default

Change the document root (default is /var/www)

Restart Apache for changes to take effect.

Adding Virtual Hosts

To add virtual hosts to Apache, all you need to do is create a config in /etc/apache2/sites-available/.

The config files should look similar to this:

<VirtualHost 192.168.0.5>>
        ServerName virtual.hostname.com
        DocumentRoot /usr/www/path/to/files
</VirtualHost>

To enable the new site run:

sudo a2ensite <config name>

To disable a site run:

sudo a2dissite <config name>

The next thing to do is to enable virtual hosts in your Apache configuration. The simplest way to do this is to create a file called /etc/apache2/conf.d/virtual.conf and include the following content in it:

#
#  We're running multiple virtual hosts.
#
NameVirtualHost *

Enable mod_headers on Apache

For customization of HTTP request and response headers, you should enable mod_headers on Apache.

sudo a2enmod headers

Increase PHP File Upload Size

The default PHP installation will restrict you to a maximum of 2 MB however there are many instances this needs to be increased. This can be done by modifying the PHP.ini file.

sudo pico /etc/php5/apache2/php.ini

There are two settings to be changed. Locate and modify the following lines.

upload_max_filesize = 2M
post_max_size = 8M

You will need to restart Apache for changes to take effect.

Installing Xdebug

The Xdebug  extension helps you debug your script by providing a lot of valuable debug information.

This can be quickly installed in Ubuntu using the following command:

sudo aptitude install php5-xdebug

You can verify successful installation by calling:

php -v

If successful you should see something like the following:

PHP 5.3.2-1ubuntu4.2 with Suhosin-Patch (cli) (built: May 13 2010 20:01:00)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
    with Xdebug v2.0.5, Copyright (c) 2002-2008, by Derick Rethans

For more information, please see this article which also covers using XDebug to analyse PHP performance.