1 files changed, 77 insertions, 0 deletions
diff --git a/lib/api/custom_attributes_endpoints.rb b/lib/api/custom_attributes_endpoints.rb
new file mode 100644
index 00000000000..5000aa0d9ac
--- /dev/null
+++ b/lib/api/custom_attributes_endpoints.rb
@@ -0,0 +1,77 @@
+module API
+  module CustomAttributesEndpoints
+    extend ActiveSupport::Concern
+
+    included do
+      attributable_class = name.demodulize.singularize
+      attributable_key = attributable_class.underscore
+      attributable_name = attributable_class.humanize(capitalize: false)
+      attributable_finder = "find_#{attributable_key}"
+
+      helpers do
+        params :custom_attributes_key do
+          requires :key, type: String, desc: 'The key of the custom attribute'
+        end
+      end
+
+      desc "Get all custom attributes on a #{attributable_name}" do
+        success Entities::CustomAttribute
+      end
+      get ':id/custom_attributes' do
+        resource = public_send(attributable_finder, params[:id]) # rubocop:disable GitlabSecurity/PublicSend
+        authorize! :read_custom_attribute
+
+        present resource.custom_attributes, with: Entities::CustomAttribute
+      end
+
+      desc "Get a custom attribute on a #{attributable_name}" do
+        success Entities::CustomAttribute
+      end
+      params do
+        use :custom_attributes_key
+      end
+      get ':id/custom_attributes/:key' do
+        resource = public_send(attributable_finder, params[:id]) # rubocop:disable GitlabSecurity/PublicSend
+        authorize! :read_custom_attribute
+
+        custom_attribute = resource.custom_attributes.find_by!(key: params[:key])
+
+        present custom_attribute, with: Entities::CustomAttribute
+      end
+
+      desc "Set a custom attribute on a #{attributable_name}"
+      params do
+        use :custom_attributes_key
+        requires :value, type: String, desc: 'The value of the custom attribute'
+      end
+      put ':id/custom_attributes/:key' do
+        resource = public_send(attributable_finder, params[:id]) # rubocop:disable GitlabSecurity/PublicSend
+        authorize! :update_custom_attribute
+
+        custom_attribute = resource.custom_attributes
+          .find_or_initialize_by(key: params[:key])
+
+        custom_attribute.update(value: params[:value])
+
+        if custom_attribute.valid?
+          present custom_attribute, with: Entities::CustomAttribute
+        else
+          render_validation_error!(custom_attribute)
+        end
+      end
+
+      desc "Delete a custom attribute on a #{attributable_name}"
+      params do
+        use :custom_attributes_key
+      end
+      delete ':id/custom_attributes/:key' do
+        resource = public_send(attributable_finder, params[:id]) # rubocop:disable GitlabSecurity/PublicSend
+        authorize! :update_custom_attribute
+
+        resource.custom_attributes.find_by!(key: params[:key]).destroy
+
+        status 204
+      end
+    end
+  end
+end