Expose MiqEvent/EmsEvent group/levels in event stream OPTIONS

The timeline_events key in the response body 'data' field contains information
on the type of events, their descriptions, group levels, group names, etc.

Currently, we only support EmsEvent and MiqEvent from event_streams.

Part of ManageIQ#1090

app/controllers/api/event_streams_controller.rb

@@ -1,4 +1,13 @@
 module Api
   class EventStreamsController < BaseController
+    def options
+      render_options(@req.collection, build_additional_fields)
+    end
+
+    private
+
+    def build_additional_fields
+      {:timeline_events => EventStream.timeline_options}
+    end
   end
 end

spec/requests/event_streams_spec.rb

@@ -162,4 +162,24 @@
       expect(response).to have_http_status(:forbidden)
     end
   end
+
+  describe 'OPTIONS /api/event_streams' do
+    it 'returns expected and additional attributes' do
+      MiqEventDefinitionSet.seed
+      options(api_event_streams_url)
+
+      expect_options_results(:event_streams)
+
+      body = response.parsed_body
+      expect(body["data"].keys).to eq(["timeline_events"])
+      expect(body["data"]["timeline_events"].keys.sort).to eq(%w[EmsEvent MiqEvent])
+      expect(body["data"]["timeline_events"]["EmsEvent"].keys.sort).to eq(%w[description group_levels group_names])
+      expect(body["data"]["timeline_events"]["EmsEvent"]["group_names"].keys.sort).to include("addition", "other")
+      expect(body["data"]["timeline_events"]["EmsEvent"]["group_levels"].keys.sort).to eq(%w[critical detail warning])
+
+      expect(body["data"]["timeline_events"]["MiqEvent"].keys.sort).to eq(%w[description group_levels group_names])
+      expect(body["data"]["timeline_events"]["MiqEvent"]["group_names"].keys.sort).to include("auth_validation", "other")
+      expect(body["data"]["timeline_events"]["MiqEvent"]["group_levels"].keys.sort).to eq(%w[detail failure success])
+    end
+  end
 end