Best approach to create a background task

I'm currently developing a Ruby on Rails application that on certain moment has to import a (at least for me) medium-large dataset using a third-party API. It has to do an average of 6000 API calls. One after another. It lasts about 20 minutes.

Right now I have made a rails task that does everything as I want (calls, write to db, etc). But now I want this task/code to be ALSO called from a button on the web. I know it's not a good approach to let the controller call the task so that's why I'm asking.

I want this import code to be available to be called from a controller and a task, because later I want to be able to call this task from a cronjob, and even if it's possible to have callbacks on the progress of the task on the controller, i.e. know how many calls are left.