For legacy reasons, we host two different forums instances but still using the same tech stack/solution :
The forum tech stack is just using phpBB with a MySQL DB Worth knowing that it's almost the default phpBB stack and no real plugin added, and also meaning that (legacy) using the internal users DB, and so no SSO.
The ansible role used to deploy the app is the ansible-role-phpbb
To update between major release, we have a specific
adhoc-update-phpbb.yml that can be used to update to a version (test this first on a test instance first)