Summary:
Depends on D20111. Ref T6703. Currently, each ExternalAccount row is tied to a provider by `providerType` + `providerDomain`. This effectively prevents multiple providers of the same type, since, e.g., two LDAP providers may be on different ports on the same domain. The `domain` also isn't really a useful idea anyway because you can move which hostname an LDAP server is on, and LDAP actually uses the value `self` in all cases. Yeah, yikes.
Instead, just bind each account to a particular provider. Then we can have an LDAP "alice" on seven different servers on different ports on the same machine and they can all move around and we'll still have a consistent, cohesive view of the world.
(On its own, this creates some issues with the link/unlink/refresh flows. Those will be updated in followups, and doing this change in a way with no intermediate breaks would require fixing them to use IDs to reference providerType/providerDomain, then fixing this, then undoing the first fix most of the way.)
Test Plan: Ran migrations, sanity-checked database. See followup changes for more comprehensive testing.
Reviewers: amckinley
Reviewed By: amckinley
Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam
Maniphest Tasks: T6703
Differential Revision: https://secure.phabricator.com/D20112
