I'm in the process of migrating from an in-house user-role storage to Keycloak and I'm looking for programmatic (Java) ways to migrate all current users to the new storage. And I need your help to figure out the best approach.

At first, when reading KC documentation, I believed I could easily achieve this by implementing a User Federation provider but after diving a little more into it, and looking for examples, I can't see a way to migrate all users on-demand but simply one user at a time, possible during log-in.

Next, I tried and look into ways, such as admin-cli, REST, etc but nothing strikes me as the solution to use.

Here's what I was hoping to deliver:

* Get all roles and users from my soon-to-be deprecated storage, e.g. MySQL tables

* Add roles to KC

* Iterate users and add user to KC + map roles + update password hashes (here I know I need to implement a HashProvider)

Any hints will be appreciated!

Pires