How to enable mod_rewrite in Apache2 on Debian or Ubuntu

If you have installed Apache2 web server via apt-get or aptitude on Debian or Ubuntu systems, it has mod_rewrite module installed, but not enabled by default. After Apache2 installation, you need to enable mod_rewrite explicitly in order to enjoy its benefit.

What is mod_rewrite?

Apache2 web server boasts of extensible features which are realized by the notion of pluggable modules. When building Apache2, you compile a set of modules you think are necessary, into it. One such module is called mod_rewrite which is responsible for rewriting website URLs at the server side. For example, when user asks for "http://myserver.com/my_category/my_post.html", the requested URL is translated by mod_rewrite to "http://myserver.com/post.php?category=100&post=200", which is then handled by the web server.

Why use mod_rewrite?

Webmasters generally use mod_rewrite to improve user-friendliness and search engine friendliness of web sites by exposing more memorable and crawlable URLs to the world with mod_rewrite. Also, it can help hide any sensitive information such as query strings from URL requests, and hence can enhance website safety.

How to enable mod_write on Apache2

The default installation of Apache2 comes with mod_rewrite installed. To check whether this is the case, verify the existence of /etc/apache2/mods-available/rewrite.load.

$ cat /etc/apache2/mods-available/rewrite.load

LoadModule rewrite_module /usr/lib/apache2/modules/mod_rewrite.so

To enable and load mod_rewrite, do the rest of steps.

$ sudo a2enmod rewrite

The above command will create a symbolic link in /etc/apache2/mods-enabled.

$ ls -al /etc/apache2/mods-enabled/rewrite.load

lrwxrwxrwx 1 root root 30 Dec  9 23:10   /etc/apache2/mods-enabled/rewrite.load -> ../mods-available/rewrite.load

Then open up the following file, and replace every occurrence of "AllowOverride None" with "AllowOverride all".

$ sudo vi /etc/apache2/sites-available/default

Finally, restart Apache2.

$ sudo service apache2 restart