How to use keycloak if users and groups defined in some cloud identity provider

We have identity microservice which defines all users , groups and relation between users and group. It is possible to integrate keycloak with such microservice?
Do we need to pollute user and its attribute, user’s group into keycloak each time when user authenticated and log in to kaycloak ?

@begemot it seems to me that you are after “User Federation”. I’d suggest to take a look at the docs