Drupal Multisite with Probo | Probo.CI Documentation

You can add --site-[anything] to the end of any build’s URL – where [anything] can be anything URL safe with no periods – and Probo will still route to the appropriate container. For example, if your $BUILD_ID is “abc-123” and your normal URL is https://abc-123.probo.build, you can add --site-foo to the end of the URL. The new URL, https://abc-123--site-foo.probo.build, will still pass you through to the exact same build. This effectively gives you a way to create subdomains for your builds.

With this in mind, you can add the necessary site entries in your sites.php file to route the appropriate Probo URLs to your site folders. For example, you might want to route $BUILD_ID--site-de.probo.build to your de site folder. In sites.php this would look like:

$sites['$BUILD_ID--site-de.probo.build'] = 'de';

You can define these entries in your .probo.yaml file:

steps:
  - name: Configure Multisite
    plugin: Script
    script: |
       cd $SRC_DIR/webroot/sites
       echo "\$sites['$BUILD_ID--site-de.probo.build'] = 'de';" >> sites.php

You also need to generate your own settings.php files for each site.