[keycloak-dev] migrating custom User Fed Providers

[Bill Burke]

Not sure what to do about migration of custom User Fed providers.  The 
issue is around imported users as they have a federation link 
specified.  What I think I can do is check to see if the provider exists 
for the linked user when queried, if it doesn't remove the user.  This 
would slowly remove old linked users.  This is the easiest solution.

I can do something similar to LDAP in which if a UserStorage with same 
provider id exists, then just port it to the new component model.  If 
there isn't a similar provider remove all users that are linked.  This 
becomes much harder as this isn't as simple as deleting the user from 
the user table.  I'll have to port all the queries that are executed 
from JPA to JDBC when a user is removed.

More work....