Keycloak custom user federation with user attributes - keycloak

Question

I have implemented a custom UserStorageProvider with AbstractUserAdapter for Keycloak for retrieving users from external DB and login users with credentials stored in that DB. All works ok and the data is read only via Keycloak admin panel.
I wanted to add additional attributes to users from data stored in external DB, I would like to add this data to the token via Attribute Mapper, is there a way to do it? Or do II need to implement AbstractUserAdapterFederatedStorage? The problem with the later is that it is not read only and allows to edit the user data transferred to the keycloak user store.

Answer 1

It really depends on your implementation. If you have access to desired data for attributes and to the user, you can simply assign new attributes to him, i.e:
KeycloakSession session = // get session somewhere
RealmModel currentRealm = session.getContext().getRealm();
UserModel user = getUserSomehow(session, currentRealm);
user.setSingleAttribute("attributeName", "attributeValue");
...
private UserModel getUserSomehow(KeycloakSession session, RealmModel realm) {
return KeycloakModelUtils.findUserByNameOrEmail(context.getSession(), context.getRealm(), "<username>");
// or (cached model):
// return session.users().getUserById("<userId>", realm);
// or (Un-cached model):
// return session.userStorageManager().getUserById("<userId>", realm);
}