Redirect wildcard subdomains to subdirectory, without changing URL in address bar - apache

Question

I've read a lot of questions and answers about this on here but none that seem to solve my specific problem.
I want to redirect any subdomain to the subdirectory to match.
So: x.domain.com would go to domain.com/x, and y.domain.com would go to domain.com/y - But I want to do this without the URL in the address bar changing.
Here's what I have so far:
Options +FollowSymLinks
RewriteEngine on
RewriteBase /
RewriteCond %{HTTP_HOST} !^(www)\. [NC]
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com [NC]
RewriteRule ^ /%1 [P,L]
But this takes me to a website redirect loop, with an incorrect address in the URL bar where the subdomain still exists.
For example, x.domain.com takes me to x.domain.com/x and I get a redirect loop error.
I'd be grateful if anyone can point me in the right direction! Nothing I change seems to work...

Answer 1

First of all, make sure that the vhost in the apache configuration is properly configured and all subdomains of domain.com are in the same host configuration (wildcard):
<VirtualHost *:80>
ServerName domain.com
ServerAlias *.domain.com
...
You can get the redirect working with the following htaccess configuration:
RewriteEngine on
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com
RewriteRule ^(.*)$ http://domain.com/%1/$1 [L,NC,QSA]
Now, if you open asd.domain.com it should redirect you to domain.com/asd.
You will still have the problem, that the redirect is visible in the URL address bar. In order to prevent this, enable mod_proxy (and load the submodules) on your server and exchange the "L" flag with the "P" flag:
RewriteEngine on
RewriteCond %{HTTP_HOST} ^(.*)\.domain\.com
RewriteRule ^(.*)$ http://domain.com/%1/$1 [P,NC,QSA]
If this doesn't work, viewing the vhost configuration and the content of error.log on subdomain calling will be helpful!
References:
.htaccess rewrite subdomain to directory
http://httpd.apache.org/docs/2.2/mod/mod_proxy.html
http://httpd.apache.org/docs/2.2/rewrite/flags.html#flag_p

Answer 2

This can be achieved in .htaccess without mod_proxy provided your server is configured to allow wildcard subdomains. (I achieved that in JustHost by creating a subomain manually named *). Add this to your .htaccess file:
RewriteEngine On
RewriteCond %{HTTP_HOST} !^www\.website\.com$
RewriteCond %{HTTP_HOST} ^(\w+)\.website\.com$
RewriteCond %{REQUEST_URI}:%1 !^/([^/]+)/([^:]*):\1
RewriteRule ^(.*)$ /%1/$1 [QSA]

Answer 3

I named the subdirectories under $_SERVER['DOCUMENT_ROOT'] match with my subdomains like so:
/
var/
www/
html/
.htaccess
subdomain1.domain.com/
subdomain2.domain.com/
subdomain3.domain.com/
Where /var/www/html stand as 'DOCUMENT_ROOT'. Then put following code in the .htaccess file:
RewriteEngine on
RewriteCond %{REQUEST_URI} !^/%{HTTP_HOST}/
RewriteRule (.*) /%{HTTP_HOST}/$1 [L]
It works as redirect wildcard subdomains to subdirectories, without changing URL in address bar.
Beside of vhost, you may also put the subdirectories outside root and access it using alias as described here. Then put the same .htaccess code in that location.