Automatic subdomains

Setting up automatic subdomains

Webhosting from Platon Technologies enables you to automatically create subdomains on your domain; you only need to create a folder with the name of the desired subdomain in the SFTP space of the respective domain.

This functionality is not enabled by default. Some initial setup is required before it is switched on, and that can be accompanied by a short outage of your domain.

Therefore before enabling subdomains, we ask you to read this guide carefully to the end, to keep to the order of the steps and to discuss anything unclear with us. The actual activation of subdomains in our system is done on our side, so we kindly ask you to let us know in good time that you need automatic subdomains, so that we can agree on a specific time for the activation.

In principle, creating subdomains relies on a special A record in the form *.yourdomain.ext, which makes every folder created in the SFTP space of the domain a subdomain. So once you create a folder, a subdomain in the form foldername.yourdomain.ext comes into being, and the A record above points it to the right place.

Setting that A record naturally disables the default records www.yourdomain.ext and yourdomain.ext. Without carrying out the measures below, that would take your domain down, along with the content it shows today.

To keep the time your domain is unavailable to a minimum, we recommend the following procedure:

1. Create special folders in SFTP (www/ and _/)
2. Copy the contents to www/ and create a redirect
3. Create an A record *.yourdomain.ext
4. Enable automatic subdomains

1. Creating Special folders in SFTP (www/ and _/)

As it has already been mentioned, by enabling the creation of automatic subdomains every folder in SFTP will become a subdomain. This means that it is necessary to create also folders for default domain forms – in the SFTP space of the respective domain (in the folder web/yourdomain.ext/). You need to create two special folders here:

www – for the format www.yourdomain.ext and _ (underscore) – for the format without www

(When creating the folder DO NOT type the slash symbol at the end.)

2. Copying the content to WWW and creating a redirect

The folder www/ (web/yourdomain.ext/www/) will replace the previous main folder (web/yourdomain.ext). The content of the SFTP space (domain) needs to be moved here. The folder _/ is for the record without www, so its content appears when someone types your domain name without www. The content of that folder is usually identical to www, so you would have to copy the same content there. That would, of course, mean a lot of unnecessary work and make updating your site harder. Instead, you can redirect the folder _/ to the folder www/ with the following steps:

In the folder _/ create a file named .htaccess (no extension, with a dot at the beginning of the name). Copy the following code and paste it into the file:

<?php
#
# This is universal permanent HTTP redirector created by Platon Technologies
# for multihosting and auto-subdomains purposes.
#
# Should be placed into _/ subdirectory in virtual document root.
# Actual website content goes into www/ subdirectory.
RewriteEngine on
RewriteBase /
RewriteRule ^(.*)$ http://www.%{HTTP_HOST}/$1 [R=301,L]
?>

Once the file is saved, the automatic redirect of the domain is set to the www/ folder, where the domain’s content is stored.

Please note one more important thing: when you copy the content of the website into the www/ folder, the website code must be adapted to the move, which means that every fixed path that previously pointed to public_html / domain.ext has to be updated to the new location.

3. Creating an A Record *.yourdomain.ext

It is now necessary to edit an A record that will redirect subdomains to your SFTP space. The A record is created or edited on our web portal https://setup.platon.sk/ First log in and in the section DNS click on Domain List and select the respective domain.

The list of A records of the domain is at the bottom of the screen.

After clicking the edit (pencil) icon to the left of the A record www.yourdomain.ext, change "www" to * (an asterisk) in the Name line. The IP address in the Content line should remain unchanged.

4. Enabling Automatic Subdomains

Everything is now ready for enabling automatic subdomains. You can enable them by editing the virtualhost yourdomain.ext and ticking the box "enable automatic subdomains". Otherwise, please contact us with this request, and we will activate the functionality as agreed. As soon as we activate automatic subdomains in our system, we will delete the www record from the A records in the domain’s DNS. If at that point the content of your website has not been copied into the new folder www/ and the redirect has not been set up according to the procedure above, your website will stop working.

In case you need assistance with these settings, please contact us at helpdesk@platon.net.