Share Data Between Two Ignition Instances

A data center provider uses Ignition for monitoring assets in their ownership. A client/customer that leases white space in the data center and also uses Ignition for assets in the whitespace that are owned by the client/customer.

The client/customer would like to ingest ignition data from the data center providers ignition into the client/customer's ignition. Each Ignition instance is on it's own.

What is the best way to share data center provider ignition with client/customer ignition?

The generic solution is to use WebDev in the data center provider Ignition instance to expose information via an API.

For simple cases, a shared database connection might suffice.