Add support for FTP assets for releases

Extend the list of supported protocols to include FTP.

app/models/releases/link.rb

@@ -6,7 +6,7 @@ module Releases
 
     belongs_to :release
 
-    validates :url, presence: true, url: true, uniqueness: { scope: :release }
+    validates :url, presence: true, url: { protocols: %w(http https ftp) }, uniqueness: { scope: :release }
     validates :name, presence: true, uniqueness: { scope: :release }
 
     scope :sorted, -> { order(created_at: :desc) }

changelogs/unreleased/57410-api-create-release-link-with-ftp-address-return-400-bad-request.yml

@@ -0,0 +1,5 @@
+---
+title: Add support for FTP assets for releases
+merge_request: 25071
+author: Robert Schilling
+type: added

doc/api/releases/links.md

@@ -3,6 +3,7 @@
 > [Introduced](https://gitlab.com/gitlab-org/gitlab-ce/issues/41766) in GitLab 11.7.
 
 Using this API you can manipulate GitLab's [Release](../../user/project/releases/index.md) links. For manipulating other Release assets, see [Release API](index.md).
+GitLab supports links links to `http`, `https`, and `ftp` assets.
 
 ## Get links
 

spec/models/releases/link_spec.rb

@@ -77,4 +77,28 @@ describe Releases::Link do
 
     it { is_expected.to be_truthy }
   end
+
+  describe 'supported protocols' do
+    where(:protocol) do
+      %w(http https ftp)
+    end
+
+    with_them do
+      let(:link) { build(:release_link, url: protocol + '://assets.com/download') }
+
+      it 'will be valid' do
+        expect(link).to be_valid
+      end
+    end
+  end
+
+  describe 'unsupported protocol' do
+    context 'for torrent' do
+      let(:link) { build(:release_link, url: 'torrent://assets.com/download') }
+
+      it 'will be invalid' do
+        expect(link).to be_invalid
+      end
+    end
+  end
 end