Do not require resource_type for metric_rollups subcollection

resource_type is set by the controller when the request is made based off of the collection that has been specified. This returns a more appropriate error message

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1540254

lib/services/api/metric_rollups_service.rb

@@ -1,11 +1,12 @@
 module Api
   class MetricRollupsService
     REQUIRED_PARAMS = %w(resource_type capture_interval start_date).freeze
+    QUERY_PARAMS = %w(resource_ids).freeze
 
     attr_reader :params
 
     def initialize(params)
-      @params = params
+      @params = params.slice(*(REQUIRED_PARAMS + QUERY_PARAMS))
       validate_required_params
       validate_capture_interval
     end
@@ -20,9 +21,8 @@ def query_metric_rollups
     private
 
     def validate_required_params
-      REQUIRED_PARAMS.each do |key|
-        raise BadRequestError, "Must specify #{REQUIRED_PARAMS.join(', ')}" unless params[key.to_sym]
-      end
+      not_specified = REQUIRED_PARAMS - params.keys
+      raise BadRequestError, "Must specify #{not_specified.join(', ')}" unless not_specified.empty?
     end
 
     def validate_capture_interval

spec/lib/services/api/metric_rollups_service_spec.rb

@@ -8,9 +8,9 @@
 
     it 'validates the capture interval' do
       expect do
-        described_class.new(:resource_type    => 'Service',
-                            :start_date       => Time.zone.today.to_s,
-                            :capture_interval => 'bad_interval')
+        described_class.new('resource_type'    => 'Service',
+                            'start_date'       => Time.zone.today.to_s,
+                            'capture_interval' => 'bad_interval')
       end.to raise_error(Api::BadRequestError, a_string_including('Capture interval must be one of '))
     end
   end

spec/requests/services_spec.rb

@@ -1055,6 +1055,20 @@ def expect_svc_with_vms
 
       expect(response).to have_http_status(:forbidden)
     end
+
+    it 'does not require resource_type for a subcollection' do
+      api_basic_authorize(subcollection_action_identifier(:services, :metric_rollups, :read, :get))
+
+      get(url)
+
+      expected = {
+        'error' => a_hash_including(
+          'message' => 'Must specify capture_interval, start_date'
+        )
+      }
+      expect(response).to have_http_status(:bad_request)
+      expect(response.parsed_body).to include(expected)
+    end
   end
 
   describe 'add_provider_vms_resource' do