Expose assets in releases API

app/models/release.rb

@@ -17,4 +17,17 @@ class Release < ActiveRecord::Base
     git_tag = repository.find_tag(tag)
     repository.commit(git_tag.dereferenced_target)
   end
+
+  def sources_formats
+    @sources_formats ||= %w(zip tar.gz tar.bz2 tar).freeze
+  end
+
+  # TODO: placeholder for frontend API compatibility
+  def links
+    []
+  end
+
+  def assets_count
+    links.size + sources_formats.size
+  end
 end

lib/api/entities.rb

@@ -1099,6 +1099,20 @@ module API
       expose :created_at
       expose :author, using: Entities::UserBasic, if: -> (release, _) { release.author.present? }
       expose :commit, using: Entities::Commit
+
+      expose :assets do
+        expose :assets_count, as: :count
+        expose :links
+        expose :sources do |release, _opts|
+          archive_path = "#{release.project.path}-#{release.tag.tr('/', '-')}"
+          release.sources_formats.map do |format|
+            {
+              format: format,
+              url: Gitlab::Routing.url_helpers.project_archive_url(release.project, id: File.join(release.tag, archive_path), format: format)
+            }
+          end
+        end
+      end
     end
 
     class Tag < Grape::Entity