Bug 1360186

Patrik - Since we support tagging on so many objects (but not all) the tagging methods exposed to the automate service model were implemented at the base object.  We never dealt with properly handling active_record objects that do not include tagging.

The suggested approach here is to add two new methods (one class/one instance) both called "taggable?" to the base automate service model (lib/miq_automation_engine/engine/miq_ae_service_model_base.rb) which would return true/false if the class or instance supports tagging.

I'm thinking it would look like this:
def taggable?
  self.class.taggable?
end

def self.taggable?
  model.respond_to?(:tags)
end

We will need rspec tests, but to test in the rails console you can do this once you have the methods created:

  $evm = MiqAeMethodService::MiqAeService.new(MiqAeEngine::MiqAeWorkspaceRuntime.new)

  # Test class methods:
  $evm.vmdb(:vm).taggable?
  => true
  vm = $evm.vmdb(:lan).taggable?
  => false

  # Test instance methods:
  $evm.vmdb(:vm).first.taggable?
  => true
  vm = $evm.vmdb(:lan).first.taggable?
  => false


Then we need to update the tagging methods in miq_ae_service_model_base.rb (tagged_with?, tags, tag_assign, tag_unassign) to verify that tagging is supported on the current object and raise an error if not.

We should add a new error class here for this error here:
lib/miq_automation_engine/miq_ae_exception.rb


Related talk topic:
http://talk.manageiq.org/t/should-all-models-be-taggable/1613

Solved in PR https://github.com/ManageIQ/manageiq/pull/10230

Verified in 5.7.0.0

irb(main):007:0> $evm.vmdb(:Lan).all.last.taggable?
=> true
irb(main):008:0> $evm.vmdb(:Lan).all.last.tags
=> []
irb(main):015:0> $evm.vmdb(:Lan).all.last.tag_assign 'location/chicago'
=> true
irb(main):016:0> $evm.vmdb(:Lan).all.last.tags
=> ["location/chicago"]

Works as expected.