If you are building a fresh new Kalastack (not required if you use Kalabox), see the README file in the code base:
https://github.com/kalamuna/kalastack/blob/3.x/README.md
+
https://github.com/kalamuna/kalastack/wiki/How-to-Participate
To add solr, reference https://github.com/kalamuna/kalastack/wiki/Adding-Solr-to-Kalastack
Drupal Configuration
- Enable Pantheon Solr module
- Visit `admin/config/search/pantheon_solr`
- Turn on `3.x/schema.xml` schema
- Mark for reindex with `drush @pantheon.%site%.%env% --strict=0 search-api-reindex`
- Do the indexing with `drush @pantheon.%site%.%env% --strict=0 search-api-index`