Remove protocol from Dependency Proxy UI

Remove the protocol from the Dependency Proxy URL
on the group page.

Rename to Dependency Proxy Image Prefix to be more
accurate.

Changelog: changed

app/helpers/groups_helper.rb

@@ -64,10 +64,13 @@ module GroupsHelper
       .count
   end
 
-  def group_dependency_proxy_url(group)
+  def group_dependency_proxy_image_prefix(group)
     # The namespace path can include uppercase letters, which
     # Docker doesn't allow. The proxy expects it to be downcased.
-    "#{group_url(group).downcase}#{DependencyProxy::URL_SUFFIX}"
+    url = "#{group_url(group).downcase}#{DependencyProxy::URL_SUFFIX}"
+
+    # Docker images do not include the protocol
+    url.partition('//').last
   end
 
   def group_icon_url(group, options = {})

app/views/groups/dependency_proxies/_url.html.haml

-- proxy_url = group_dependency_proxy_url(@group)
+- proxy_url = group_dependency_proxy_image_prefix(@group)
 
-%h5.prepend-top-20= _('Dependency proxy URL')
+%h5.prepend-top-20= _('Dependency proxy image prefix')
 
 .row
   .col-lg-8.col-md-12.input-group

locale/gitlab.pot

@@ -10977,10 +10977,10 @@ msgstr ""
 msgid "Dependency proxy"
 msgstr ""
 
-msgid "Dependency proxy URL"
+msgid "Dependency proxy feature is limited to public groups for now."
 msgstr ""
 
-msgid "Dependency proxy feature is limited to public groups for now."
+msgid "Dependency proxy image prefix"
 msgstr ""
 
 msgid "DependencyProxy|Toggle Dependency Proxy"

spec/helpers/groups_helper_spec.rb

@@ -19,11 +19,15 @@ RSpec.describe GroupsHelper do
     end
   end
 
-  describe '#group_dependency_proxy_url' do
+  describe '#group_dependency_proxy_image_prefix' do
+    let_it_be(:group) { build_stubbed(:group, path: 'GroupWithUPPERcaseLetters') }
+
     it 'converts uppercase letters to lowercase' do
-      group = build_stubbed(:group, path: 'GroupWithUPPERcaseLetters')
+      expect(group_dependency_proxy_image_prefix(group)).to end_with("/groupwithuppercaseletters#{DependencyProxy::URL_SUFFIX}")
+    end
 
-      expect(group_dependency_proxy_url(group)).to end_with("/groupwithuppercaseletters#{DependencyProxy::URL_SUFFIX}")
+    it 'removes the protocol' do
+      expect(group_dependency_proxy_image_prefix(group)).not_to include('http')
     end
   end