Restore instead of recreate #

When the API no longer holds an object, the provider restores it from state instead of creating a new one. The usual advice for a remote object that is gone is to drop it from state and let the next plan create another. For the resources that carry secrets or addressing that would be a loss: a new tenant would mean new keys, and a new workload would mean a new address.

The present attribute #

present goes false when the API no longer holds the object, which makes the next plan an update. The update sends the index and secrets back from state. The API keeps that index when it is free, and issues a new one only when another tenant took it ( ADR-0012 §5, ADR-0015 §5).

secrets_stored: false triggers the same path, for an object the API still lists but whose secrets it can no longer read.

Wi-Fi keys #

A restore sends the key back, and the wireless controller is made to match the devices. The key in state is what the tenant’s devices were flashed with, and those devices cannot be asked to change.

The flip side: terraform apply -replace, or removing and re-adding the block, issues a new key, and every device flashed with the old one stops associating until it is reflashed. Nothing guards against that, because revoking is sometimes exactly what is meant.

Broker accounts #

The state holds the only copy of a broker password. The API keeps a bcrypt hash, so unlike a Wi-Fi key it cannot resupply one from its own records. Two things follow:

• A restore sends the password back from state, so the broker is made to match the clients.
• When a create fails at its last step, the provider keeps the account it was handed, password included, rather than letting the error discard it. The account’s status is not ready, so the next plan retries it.

Topic patterns are written relative to the tenant: lightstand/+/scene, never tdemo/lightstand/+/scene. The API writes the prefix. granted_publish and granted_subscribe report the absolute form the broker enforces. State records the relative form, so a grant that changed on the broker shows as a diff and the next apply corrects it.

Device addresses #

A device address is restored the same way, though it is no secret. The device network is shared by every tenant, so the API allocates the address rather than deriving it, and the state is what remembers which one. A restore asks for the same address again. Dropping the resource from state would let a rebuilt API hand the device whichever address was lowest at that moment.