How to get the ActiveStorage attachment URL in a rake task?

Question

I have a rake task which stores images in ActiveStorage. In the same rake task I need the attachment URL of those images.

In a normal Rails context, I'd use url_for(my_attachment). That helper is not available in a rake task though.

I tried to include the route helper:

task my_task: :environment do
  include MyApp::Application.routes.url_helpers

  attachment = my_model.image.attach(..)
  url_for(attachment)
end

Which results in:

*** NoMethodError Exception: undefined method `attachment_url' for main:Object

Is there any way to get the public URL of an attachment in a rake task?

Answer 1

I wasted a lot of time looking for get a file URL working on a Module file, but here is the answer:

If you need to create a link from outside of controller/view context (Background jobs, Cronjobs, etc.), you can access the rails_blob_path like this:

Rails.application.routes.url_helpers.rails_blob_path(user.avatar, only_path: true)

I founded this on this link Redirect Mode :: Active Storage