If a module has been imported and the key types are identified for that puppet class but they change i.e. they alter from an array to a string or maybe to a null value i.e. false. It fails to update the DB accordingly with the new changes.

class ntp($packages = []) { }

Results in:

SELECT DISTINCT "lookup_keys".* FROM "lookup_keys" INNER JOIN "environment_classes" ON "lookup_keys"."id" = "environment_classes"."lookup_key_id" WHERE "environment_classes"."puppetclass_id" = 99 AND "lookup_keys"."key" = 'packages' AND (environment_classes.lookup_key_id is NOT NULL) ORDER BY lookup_keys.key LIMIT 1;
id | key | created_at | updated_at | puppetclass_id | default_value | path | description |
validator_type | validator_rule | is_param | key_type | override | required | lookup_values_count
-----+----------+----------------------------+----------------------------+----------------+---------------+------+-------------+
----------------+----------------+----------+----------+----------+----------+---------------------
292 | packages | 2013-10-03 09:44:35.514242 | 2013-10-03 09:44:35.514242 | | --- [] | | | | | t | array | f | f | 0

Override is set to false:

def update_parameter(db_class, changed_params)
    changed_params["updated"].each do |param_name, value|
      key = db_class.class_params.find_by_key param_name
      if key.override == false
        key.default_value = value
        key.save!
        fh.close
      end
    end
  end

If the code alters to

class ntp($packages = false) { } or class ntp($packages = 'anything') { }

When the import shows that there are updates to NTP, it then throws an error. This seems to be due to the fact that it's type has altered from an array to something different i.e. string, or maybe boolean.

LookupKey Load (2.0ms)  SELECT DISTINCT "lookup_keys".* FROM "lookup_keys" INNER JOIN "environment_classes" ON "lookup_keys"."id" = "environment_classes"."lookup_key_id" WHERE "environment_classes"."puppetclass_id" = 99 AND "lookup_keys"."key" = 'packages' AND (environment_classes.lookup_key_id is NOT NULL) ORDER BY lookup_keys.key LIMIT 1
   (0.8ms)  BEGIN
   (0.7ms)  ROLLBACK
Operation FAILED: Validation failed: Default value is invalid
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/validations.rb:56:in `save!'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/attribute_methods/dirty.rb:33:in `save!'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/transactions.rb:246:in `block in save!'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/transactions.rb:295:in `block in with_transaction_returning_status'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/transactions.rb:208:in `transaction'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/transactions.rb:293:in `with_transaction_returning_status'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/transactions.rb:246:in `save!'
/usr/share/foreman/app/models/puppet_class_importer.rb:214:in `block in update_parameter'
/usr/share/foreman/app/models/puppet_class_importer.rb:206:in `each'
/usr/share/foreman/app/models/puppet_class_importer.rb:206:in `update_parameter'
/usr/share/foreman/app/models/puppet_class_importer.rb:201:in `block in update_classes_in_foreman'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/relation/delegation.rb:6:in `each'
/opt/rh/ruby193/root/usr/share/gems/gems/activerecord-3.2.8/lib/active_record/relation/delegation.rb:6:in `each'
/usr/share/foreman/app/models/puppet_class_importer.rb:194:in `update_classes_in_foreman'
/usr/share/foreman/app/models/puppet_class_importer.rb:54:in `block in obsolete_and_new'
/usr/share/foreman/app/models/puppet_class_importer.rb:46:in `each'
/usr/share/foreman/app/models/puppet_class_importer.rb:46:in `obsolete_and_new'
/usr/share/foreman/lib/foreman/controller/environments.rb:28:in `obsolete_and_new'
/opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/implicit_render.rb:4:in `send_action'
/opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/base.rb:167:in `process_action'
/opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/action_controller/metal/rendering.rb:10:in `process_action'
/opt/rh/ruby193/root/usr/share/gems/gems/actionpack-3.2.8/lib/abstract_controller/callbacks.rb:18:in `block in process_action'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:527:in `block (3 levels) in run_3890897385267331029__process_action__4051149281358796367__callbacks'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in conditional_callback_around_5615'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:326:in `around'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:310:in `_callback_around_5443'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:214:in `_conditional_callback_around_5615'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:526:in `block (2 levels) in _run_3890897385267331029__process_action__4051149281358796367__callbacks'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:215:in `block in conditional_callback_around_5614'
/usr/share/foreman/lib/foreman/thread_session.rb:31:in `clear_thread'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:214:in `_conditional_callback_around_5614'
/opt/rh/ruby193/root/usr/share/gems/gems/activesupport-3.2.8/lib/active_support/callbacks.rb:415:in `block in _run_3890897385267331029__process_action__4051149281358796367__callbacks'