1 files changed, 46 insertions, 0 deletions
diff --git a/app/controllers/projects/design_management/designs/resized_image_controller.rb b/app/controllers/projects/design_management/designs/resized_image_controller.rb
new file mode 100644
index 00000000000..50a997f32db
--- /dev/null
+++ b/app/controllers/projects/design_management/designs/resized_image_controller.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+# Returns smaller sized design images
+module Projects
+  module DesignManagement
+    module Designs
+      class ResizedImageController < Projects::DesignManagement::DesignsController
+        include SendFileUpload
+
+        before_action :validate_size!
+
+        skip_before_action :default_cache_headers, only: :show
+
+        def show
+          relation = design.actions
+          relation = relation.up_to_version(sha) if sha
+          action = relation.most_recent.first
+
+          return render_404 unless action
+
+          # This controller returns a 404 if the  the `size` param
+          # is not one of our specific sizes, so using `send` here is safe.
+          uploader = action.public_send(:"image_#{size}") # rubocop:disable GitlabSecurity/PublicSend
+
+          return render_404 unless uploader.file # The image has not been processed
+
+          if stale?(etag: action.cache_key)
+            workhorse_set_content_type!
+
+            send_upload(uploader, attachment: design.filename)
+          end
+        end
+
+        private
+
+        def validate_size!
+          render_404 unless ::DesignManagement::DESIGN_IMAGE_SIZES.include?(size)
+        end
+
+        def size
+          params[:id]
+        end
+      end
+    end
+  end
+end