Htaccess non sensible subdomains - apache

Question

While I was searching for a hosting I found one called co.gp (they have more), so this hosting was great and I discovered something on it that it allows you to put any fakes subdomain you want for example.
If your website it's example.org the hosting allows you to put test1.example.org or test2.example.org.
I searched alot with the help of htaccess but I couldn't make one Like I'm looking for. So my question here. How Can I make fakes subdomains in my website ?
Ps : I don't want subdomains to be redirect for example if someone type test.example.org/something I want it to be the same as example.org/something.

Answer 1

Htaccess files will not be of much help here, because they are located under the document root, and are therefore evaluated after apache has determined which virtualhost points to this specific document root.
Assuming your DNS entries are well-configured, You should instead modify directly the apache main configuration.
If every subdomain points to a different document root, you will have to create a virtual host for each one:
<VirtualHost *>
ServerName example.org
DocumentRoot /path/to/example.org
# ...
</VirtualHost>
<VirtualHost *>
ServerName test1.example.org
DocumentRoot /path/to/test1.example.org
# ...
</VirtualHost>
If, instead, several subdomains point to a single document root, you can use the ServerAlias directive:
<VirtualHost *>
ServerName example.org
ServerAlias test1.example.org
DocumentRoot /path/to/example.org
# ...
</VirtualHost>
If all of the possible subdomains point to the same document root, you can relieve yourself from the pain of listing every subdomain in the ServerAlias list, and use a wildcard instead:
<VirtualHost *>
ServerName example.org
ServerAlias *.example.org
DocumentRoot /path/to/example.org
# ...
</VirtualHost>
There are of course more configurations directives needed to ensure each virtual host works properly, but these are the main building blocks you should understand to have a working setup.