openstack-browser shows which projects and instances use specific puppet classes.
That feature is really useful and used on a regularly basis.
If a project is deleted though it does not seem to forget about a role being used in it.
Example:
https://openstack-browser.toolforge.org/puppetclass/role::simplelap lists
Project: sugarcrm
officetools.sugarcrm.eqiad.wmflabs
But if you click the instance name you get:
officetools.sugarcrm.eqiad.wmflabs Project: sugarcrm Unknown server 'officetools.sugarcrm.eqiad.wmflabs'. Are you just guessing?
Arturo has confirmed the project sugarcrm has been deleted and said:
< arturo> in this case, I think it should forget about that particular role-->instance association
< arturo> it already forgot about the project and the instance, but no the role association