WordPress, Apache2, Permalinks and mod_rewrite under Ubuntu

Installing WordPress is pretty straightforward and needs no further clarification here.  But getting Permalinks to work – well that is a different story.  That is not well documented. Permalinks are those nice-looking URLs you can optionally create for your blog postings in WordPress.  I myself like this style: WPROOT/YYYY/MM/nice-title/.

When you try to activate that you’ll see it wants to put a .htaccess file in your blog top-level directory, which you may not have permission to write to from your admin account.  I do not because I feel that is a more secure way to run the server – as a user who cannot write to the HTML directories.  Fortunately, it generates the desired contents of the .htaccess file, which is characteristically inscrutable like most things in Apache server (I’m not a big fan of Apache).  So it will look something like this (bear in mind my WordPress blog was put in the /blog directory).

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

The main point is that it relies on the mod_rewrite module in apache2, which probably won’t work for you under a straight-up Ubuntu LAMP installation for two reasons.  And if you dig around you’ll quickly latch onto one or the other reason, but not both.

You need to activate mod_rewrite.

You need to enable mod_rewrite in your conf file.

To activate mod_rewrite run

sudo a2enmod rewrite

(of course I’m assuming you have root access).  This stands for, more-or-less, Apache2 enable module rewrite.  Note what it does, it creates symlinks from the /etc/apache2/mods-enabled directory for each module which has been enabled.  By default, mod_rewrite is NOT enabled in Ubuntu server 10.10, for some reason.

In your Apache configuration file (yours may be /etc/apache2/sites-enabled/000-default or another file in that directory) you’ll probably have this statement in your Directory section that pertains to your WordPress document root:

AllowOverride none

You will need to change it to

AllowOverride All

For instance, for me with my WordPress blog root at /var/www/blog, my Apache configuration file now looks like this:

<VirtualHost *:80>
...
        <Directory /var/www/blog>
                AllowOverride All
        </Directory>
...

Restart Apache, make sure those .htaccess lines are in your blog’s main directory, and you should be good to go.