system-role-handlers.md

System Role Handlers

This is a mechanism that allows to execute specific code depending on the system role selected during the installation which was introduced in version 3.2.21 (originally in 3.1.217.20 in the SLE-12-SP2-CASP branch).

If you prefer, you could think of them as hooks for system roles.

Types of handlers

Currently only one type of handlers exist: finish. Those handlers will be executed through the roles_finish

Defining a new handler

Handlers are just plain classes which implement a run method and live in the lib/y2system_role_handlers. The name of the file/class depends on the type of handler they implement.

For instance, if you want to define a finish handler for an ExampleRole role, just drop a file like this into lib/y2system_role_handlers.

module Y2SystemRoleHandlers
  class ExampleRoleFinish
    def run
      # Handler implementation goes here
    end
  end
end

The run method won't receive any argument and is also not expected to return any special value. Finally, exceptions will be handled like any other YaST exception.

Examples

Please, check out the yast2-caasp package for examples.