Is Federated Multi-database setup with single sign-in supported?

[revant_one]

@GeoffreyM

This way, we can have one login then install multiple apps - bulk sms, call center etc. We would like new apps are to have the option of being configured to different databases other than the one erpnext is running on for better scalability - bulk sms especially can hog the ERPNext instance if the customer decides to dispatch millions of messages at a go or if we get an influx of calls.

This is already possible if multiple apps are not expected to be frappe apps using frappe orm.

Frappe has built-in OAuth 2 provider. Use it as the central authorization server.

All your users are registered on this central Frappe/ERPNext server.

You can even login with social login keys (google, github, facebook, etc) on this central authorization server.

Add as many OAuth Client(s) as needed on this auth server, e.g bulk sms, call center, etc.

Each client is separate app with stack of its own.

I tried to make frappe app like this Custom apps for cloud users [extend ERPNext with microservices] (experimental and deprecated)

Later for a use case I used MongoDB as database and NodeJS as runtime. (active in production).

example: User visits app url (bulk-sms.example.com), gets redirected to central auth server (erp.example.com) for login, there user can login or choose to social login, after successful login user gets redirected back to the OAuth client app (bulk-sms.example.com).