Using Apache Solr with Drupal

If you are using Apache Solr with your Drupal application, there are a few ways to configure your Probo.CI build to leverage it. You will need to tell Probo.CI which version of Solr and provide the Solr core you will be using from Search API Solr. For more information on this step, see the Solr Configuration page.

In terms of Solr cores for Drupal, here are some quick links to applicable cores for Solr 7, 8, and 9:

Solr 7
Solr 8
Solr 9

With that completed, here are a few options:

1. Use the Drupal Plugin with the settingsAppend option.
2. Use the Configuration Split module to split your configuration into different environments. This is a modern method that is recommended for new builds that are already using Configuration Split for environment management.
3. Manual configuration after completed build (not recommended).

Using the Drupal Plugin with the settingsAppend Option

Copy the settingsAppend section below into the Drupal Plugin configuration on your .probo.yaml file. You should specify the machine name in the $config section of your appended settings. The example below would work for a Search API Server with the machine name solr. If your core has the machine name of solr_core then the $config key would change from search_api.server.solr to search_api.server.solr_core.

Also keep in mind that the name of your core should match the name you specified in your solr configuration. If you specifed a name of core then your full configuration would look something like the below as an example. You will need to tweak this to your specific settings.

steps:
  - name: Install and Update Drupal
    plugin: Drupal
    database: drupal-database.sql.gz
    composer: true
    databaseGzipped: true
    databaseUpdates: true
    clearCaches: true
    drupalVersion: 11
    settingsAppend: |
      $config['search_api.server.solr']['backend_config']['connector'] = 'standard';
      $config['search_api.server.solr']['backend_config']['connector_config']['scheme'] = 'http';
      $config['search_api.server.solr']['backend_config']['connector_config']['host'] = 'localhost';
      $config['search_api.server.solr']['backend_config']['connector_config']['core'] = 'drupal';
      $config['search_api.server.solr']['backend_config']['connector_config']['path'] = '/';
      $config['search_api.server.solr']['backend_config']['connector_config']['timeout'] = '5';
      $config['search_api.server.solr']['backend_config']['connector_config']['index_timeout'] = '5';
      $config['search_api.server.solr']['backend_config']['connector_config']['optimize_timeout'] = '10';
      $config['search_api.server.solr']['backend_config']['connector_config']['finalize_timeout'] = '30';
      $config['search_api.server.solr']['backend_config']['connector_config']['commit_within'] = '1000';

Using the Configuration Split Module

If your project already manages environment-specific configuration with the Configuration Split module, you can point Drupal at Probo’s Solr instance without ever touching your production configuration. The idea is to create a dedicated split that overrides only the Search API Solr server connection so that, when the split is active inside a Probo build, Drupal talks to the Solr core running on localhost instead of your production Solr host.

This guide assumes you are running Config Split 2.x on Drupal 9, 10, or 11, that your site is already set up for configuration management (drush cex / drush cim), and that you have defined a Solr core in your .probo.yaml as described in the Solr Configuration page.

How This Works

Your production Search API server configuration (for example search_api.server.solr) stores the host, scheme, and core that point to your live Solr instance. Inside a Probo build, Solr is always available at http://localhost/ with the core name you defined in your solr: block. Rather than editing settings at runtime, we keep an alternate copy of just the server connection inside a partial split and activate that split during the build.

Using a partial split (as opposed to a complete split) is important: it keeps the original search_api.server.solr configuration in your default sync directory so production is never affected, while storing the Probo-specific connection values separately and merging them on top only when the split is active.

1. Create the Probo Configuration Split

Navigate to Configuration → Development → Configuration Split settings (/admin/config/development/configuration/config-split) and add a new split:

• Label: Probo
• Machine name: probo
• Storage: Folder, with a path that is committed to your repository but kept out of the default sync directory, for example ../config/splits/probo.
• Active: leave this inactive. We will activate it only inside the Probo build so it never alters your other environments.

Under the Partial Split (conditional) section, add search_api.server.solr to the Configuration items field. If your Search API server uses a different machine name, substitute it here (for example search_api.server.solr_core).

2. Capture the Probo Connection Values

With the split defined, set the Search API server to Probo’s connection details so the correct values are written into the split. You can do this on a local or throwaway environment via the Search API UI (Configuration → Search and metadata → Search API), editing the Solr server to use the Standard connector with the following values:

3. Export the Split

Export your configuration so the partial split folder is populated:

drush config:split:export -y probo
# or export everything at once
drush config:export -y

This writes a search_api.server.solr.yml file into your split folder (../config/splits/probo) containing only the Probo connection overrides. It will look similar to the following:

# ../config/splits/probo/search_api.server.solr.yml
backend_config:
  connector: standard
  connector_config:
    scheme: http
    host: localhost
    port: 8983
    path: /
    core: drupal
    timeout: 5
    index_timeout: 5
    optimize_timeout: 10
    finalize_timeout: 30
    commit_within: 1000

Commit both your updated default sync directory and the new split folder to your repository so they are available inside the build.

4. Activate the Split During Your Probo Build

Tell Drupal to enable the probo split during the build, then import configuration so the override is applied. In Config Split 2.x a split is activated by overriding its status in settings.php, which you can do directly from your Drupal plugin’s settingsAppend option:

steps:
  - name: Install and Update Drupal
    plugin: Drupal
    database: drupal-database.sql.gz
    composer: true
    databaseGzipped: true
    databaseUpdates: true
    clearCaches: true
    drupalVersion: 11
    settingsAppend: |
      $config['config_split.config_split.probo']['status'] = TRUE;

With the split active, import your configuration and reindex Solr. Add the following commands after your Drupal step:

  - name: Import configuration with the Probo split active
    command: drush -r /var/www/html config:import -y

  - name: Clear Solr Index
    command: drush -r /var/www/html sapi-r -y

  - name: Index Solr
    command: drush -r /var/www/html sapi-i --batch-size=100 -y

Because the probo split is now active, drush config:import layers the Probo Solr connection on top of your imported configuration, repointing the Search API server to the localhost core for the duration of the build. Your production and other environments continue to use the original search_api.server.solr values stored in your default sync directory, completely untouched.

Manual Configuration After Completed Build

If you choose not to use the settingsAppend solution, your Solr settings inside your Probo build need to look as follows:

Additionally you can automatically import into Solr using Drush:

  - name: Clear Solr Index
    command: drush -r /var/www/html sapi-r -y

  - name: Index Solr
    command: drush -r /var/www/html sapi-i --batch-size=100 -y

Related Articles & Information

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Drupal Plugin Solr Configuration