Changes to auto-provisioning of Heroku Postgres for Scala apps

Change effective on 26 September 2022

When a new Scala app is deployed to Heroku, the Scala buildpack triggers the provisioning of a Heroku Postgres database addon in certain conditions, in order to improve the UX of deploying Scala apps to the platform. This feature only applies to the first build of a new app, and not subsequent builds of existing apps.

Previously the Heroku Postgres database addon was always provisioned.

Now, the Heroku Postgres database is only provisioned if the app depends on one of the following database libraries/drivers:

This ensures the database is not provisioned in cases where the app uses an alternative database backend (such as MySQL), or does not use a database at all.

Apps that do not meet the new criteria but that still need a Postgres addon should either provision the addon manually, or if using Review Apps/Heroku CI the addon can be specified via app.json.