How to create multiple web sites using shared code base in Drupal 8 and Drupal 9

In this article, we are going to discuss different ways of creating multiple websites  with a single Drupal codebase. This article is applicable to Drupal 8 and Drupal 9. By default, Drupal allows creating multiple websites with separate databases for each website. Themes, modules, and libraries will be shared among the sites.

For easier maintenance and code reusability, the multi-site approach mostly recommended . one of the draw back of multi-site approach is,  during maintenance, all sites need to be in maintenance mode.

we can create multi-sites with different approaches as provided below. Each one have its own advantages and disadvantages.

1. Multi-site with separate dedicated database for each website.
2. Multi-site within the same database with the table prefix
3. Multi-site with one common shared database using Domain Access module

Before creating subsites from a main site, we need to configure the virtual host and add host entry in order to access the main site using a domain name. Here I am using XAMPP server in  windows.

Create virtual host for main site in below file.

Open below host file.

C:\Windows\System32\drivers\etc\hosts

Add host entry

127.0.0.1 digitalnadeemlocal.com

SO our main website can be  accessed using url http:// digitalnadeemlocal.com

1.Multi-site with separate dedicated database for each website

Here we are going to create another website that will have a separate database but the code base will the same as digitalnadeemlocal.com  say this as the parent site or main website.

Step 1

Create a new database. Here we are creating a database called android_digitalnadeem

Step 2

Add virtual host and mapping in host file

Add below virtual host entries in configuration file httpd-vhost file.

DocumentRoot will be mapped to main website directory which is same as path of digitalnadeemlocal.com

Here we are giving subdomain as android.digitalnadeemlocal.com

Add this  in host file. Provide below mapping in your host file.

C:\Windows\System32\drivers\etc\hosts

127.0.0.1 android.digitalnadeemlocal.com

Step3

Create a folder for site1 in your multisite: /d8multisite/sites/android.digitalnadeemlocal.com

Step4

Make a copy of /d8multisite/sites/example.sites.php called /d8multisite/sites/sites.php

Edit sites.php  and add below line at the end of the file

$sites[‘android.digitalnadeemlocal.com’] = ‘android.digitalnadeemlocal.com’;

Step5

Copy /d8multisite/sites/default/default.settings.php to the new site’s directory as settings.php:

cp sites/default/default.settings.php / sites/ android.digitalnadeemlocal.com /settings.php

access newly created subdomain and complete installation. During installation step provide new database for this website.

Clear all cache before accessing main and sub sites.

You can see all tables available in newly created website database.

If we create users in particular site, users will be available only to that website.

All modules, libraries, theme and  files  are shared between websites.

2.Multi-site within the same database with the table prefix

Follow above steps from step 2 to step 5

Access your new web site and proceed with the installation.

Provide database name as an existing main site database name and also provide table prefix. Here I Have provided values as below.

new tables with the prefix are created for each subsite.

See some of the tables in an existing database.  All tables have a corresponding table with the prefix web.

3.Multi-site with one common shared database using Domain Access module

The domain access module is a contributed module that helps to create multiple sites in same Drupal instance with users, contents and configurations are shared across the sites. Here a single database is shared between subsites and main site.

https://www.drupal.org/project/domain

By default   Drupal 8 and Drupal 9 does not allow sharing content and configuration in a multi site environment. This draw back can be resolved by using Domain Access module.

Since code base is shared between multiple sites, you have to handle contents to specific regions based on domains.

If each sites have design with difference  in layout and positioning of regions, then it will be difficult to have such a multisite environment using Domain Access module.

While creating  content , users and other entities , there will be an option to select to which domain this entity is belongs to. Based on that content will be displayed for in specific sub sites.