Why maintain multiple Drupal 8 or Drupal 9 codebase when you can use a single codebase across multiple sites/domain!
To create multiple Drupal 8 sites using a shared Drupal 8 code base, you must complete
the following steps:
1. Create a new database for the site (if there is already an existing database you can also use this by defining a prefix in the installation procedure).
2. Create a new sub directory off of the 'sites' directory with the name of your new site. (e.g.,sites/dev.YourDomain.bhj/) See the comments in the default.settings.php file for information on how to name the sub directory.
3. Copy the file sites/default/default.settings.php into the sub directory you created in the previous step. Rename the new file to settings.php.
4. Activate the multi-site feature by copying (and renaming) the file sites/example.sites.php to sites/sites.php. There is no need to edit the file unless you need site aliases. The normal site selection rules applies.
5. Adjust the permissions of the new site directory, and grant write permissions on the configuration file (settings.php).
6. In a Web browser, navigate to the URL of the new site and continue with the standard Drupal installation procedure (if you get an infinite redirection loop, check if the file install.php exists in the document root).
Note: It may also be necessary to modify your Web server's configuration file (often named httpd.conf for Apache) to allow Drupal to override Apache's settings. This is true for all installations of Drupal and is not specific to the multi-site install. Example configuration, as in /etc/apache2/sites-available/000-default.conf:
<virtualhost *:80> DocumentRoot /var/www/html/YourDomain/web/ ServerName www.dev.YourDomain.bhj ServerAlias dev.YourDomain.bhj <directory"/var/www/html/YourDomain/web/sites/dev.YourDomain.bhj"
> AllowOverride All </directory> </virtualhost> <virtualhost *:80> DocumentRoot /var/www/html/YourDomain/web/ ServerName www.dev.YourDomain.com ServerAlias dev.YourDomain.com <directory"/var/www/html/YourDomain/web/sites/dev.YourDomain.com"
> AllowOverride All </directory> </virtualhost>