Hi,

Is there a way where I can use the JSON-based import (or any other import that can be executed before Keycloak is accessible to users) to import users and groups into an existing realm?

The relevant bits of the manual appear to be here: https://keycloak.github.io/docs/userguide/keycloak-server/html/export-import.html

I don't want to overwrite pre-existing realm configuration, other then the groups and users. So for, neither the 'IGNORE_EXISTING' nor the 'OVERWRITE_EXISTING' strategy appear to have the desired effect: one skips importing data completely (as the realm already exists), the other causes the entire realm to be replaced.

Regards,

Guus