(CONT-761) Add custom_generate as a feature

Allows the generate function to be utilized in order to manually create an array of types to be enforced. Used within the firewall module in order to enact the Purge functionality.

Author: david22swan

lib/puppet/resource_api.rb

@@ -136,6 +136,23 @@ def rsapi_canonicalized_target_state
         @rsapi_canonicalized_target_state
       end
 
+      # Method is used to custom generate resources which are then applied by Puppet
+      def generate
+        # If feature `custom_generate` has been set then call the generate function within the provider and return the given results
+        return unless type_definition&.feature?('custom_generate')
+        should_hash = rsapi_canonicalized_target_state
+        is_hash     = rsapi_current_state
+        title       = rsapi_title
+
+        # Ensure that a custom `generate` method has been created within the provider
+        raise(Puppet::DevError, 'No generate method found within the types provider') unless my_provider.respond_to?(:generate)
+        # Call the providers custom `generate` method
+        rules_resources = my_provider.generate(context, title, is_hash, should_hash)
+
+        # Return array of resources
+        rules_resources
+      end
+
       def rsapi_current_state
         refresh_current_state unless @rsapi_current_state
         @rsapi_current_state

lib/puppet/resource_api/type_definition.rb

@@ -36,7 +36,7 @@ def validate_schema(definition, attr_key)
       Puppet::ResourceApi::DataTypeHandling.validate_ensure(definition)
 
       definition[:features] ||= []
-      supported_features = %w[supports_noop canonicalize custom_insync remote_resource simple_get_filter].freeze
+      supported_features = %w[supports_noop canonicalize custom_insync remote_resource simple_get_filter custom_generate].freeze
       unknown_features = definition[:features] - supported_features
       Puppet.warning("Unknown feature detected: #{unknown_features.inspect}") unless unknown_features.empty?
     end

spec/puppet/resource_api_spec.rb

@@ -1690,6 +1690,61 @@ def set(_context, changes)
         end
       end
 
+      context 'with a provider that has a custom
+       generate', agent_test: true do
+        let(:definition) do
+          {
+            name: 'generator',
+            desc: 'some desc',
+            attributes: {
+              name: {
+                type: 'String',
+                desc: '',
+                behaviour: :namevar,
+              },
+              test_string: {
+                type: 'String',
+                desc: '',
+              },
+            },
+            features: ['custom_generate'],
+          }
+        end
+        let(:provider_class) do
+          Class.new do
+            def generate(_context, _title, _is, should)
+              # Unless purge is true, return an empty array
+              return [] unless should[:purge]
+
+              # gather a list of all rules present on the system
+              rules_resources = Puppet::Type.type(:iptables).instances
+
+              rules_resources
+            end
+
+            def get(_context)
+              []
+            end
+
+            attr_reader :last_changes
+            def set(_context, changes)
+              @last_changes = changes
+            end
+          end
+        end
+
+        before(:each) do
+          stub_const('Puppet::Provider::Generator', Module.new)
+          stub_const('Puppet::Provider::Generator::Generator', provider_class)
+        end
+
+        it { expect { described_class.register_type(definition) }.not_to raise_error }
+
+        it 'is seen as a supported feature' do
+          expect(Puppet).not_to receive(:warning).with(%r{Unknown feature detected:.*})
+        end
+      end
+
       context 'when retrieving instances' do
         it('returns an Array') { expect(type.instances).to be_a Array }
         it('returns an array of Type instances') { expect(type.instances[0]).to be_a Puppet::Type.type(:canonicalizer) }