Adam raised an interesting point, this does not work properly for ObservableModel or ObservableJob:

class A < ApplicationJob
  include Foreman::ObservableJob
  set_hook :hook_a

class B < A
  include Foreman::ObservableJob
  set_hook :hook_b
end

B.perfrom_now

The code currently triggers both A and B hooks while it should only trigger B. To solve that, we need to change the design and add tests to verify this. I am creating separate ticket because I did not want to work on this in other PR.