Move package menu entry to own partial

- new partial
- referencing

app/controllers/groups/settings/packages_and_registries_controller.rb

@@ -4,11 +4,18 @@ module Groups
   module Settings
     class PackagesAndRegistriesController < Groups::ApplicationController
       before_action :authorize_admin_group!
+      before_action :verify_packages_enabled!
 
       feature_category :package_registry
 
       def index
       end
+
+      private
+
+      def verify_packages_enabled!
+        render_404 unless group.packages_feature_enabled?
+      end
     end
   end
 end

app/views/groups/sidebar/_packages_settings.html.haml

+- if group_packages_list_nav?
+  = nav_link(controller: :packages_and_registries) do
+    = link_to group_settings_packages_and_registries_path(@group), title: _('Packages & Registries') do
+      %span
+        = _('Packages & Registries')

app/views/layouts/nav/sidebar/_group.html.haml

@@ -117,7 +117,7 @@
                 %strong.fly-out-top-item-name
                   = _('Kubernetes')
 
-      = render_if_exists 'groups/sidebar/packages'
+      = render 'groups/sidebar/packages'
 
       = render 'layouts/nav/sidebar/analytics_links', links: group_analytics_navbar_links(@group, current_user)
 
@@ -177,11 +177,7 @@
                 %span
                   = _('CI / CD')
 
-            - if Feature.enabled?(:packages_and_registries_group_settings, @group)
-              = nav_link(controller: :packages_and_registries) do
-                = link_to group_settings_packages_and_registries_path(@group), title: _('Packages & Registries') do
-                  %span
-                    = _('Packages & Registries')
+            = render 'groups/sidebar/packages_settings'
 
             = render_if_exists "groups/ee/settings_nav"
 

changelogs/unreleased/296895-group-setting-to-allow-or-prevent-duplicate-maven-uploads.yml

+---
+title: Enable group setting to allow or prevent duplicate Maven uploads
+merge_request: 53591
+author:
+type: added

doc/user/packages/maven_repository/index.md

@@ -611,6 +611,21 @@ Now navigate to your project's **Packages & Registries** page and view the publi
 When you publish a package with the same name or version as an existing package,
 the existing package is overwritten.
 
+#### Do not allow duplicate Maven packages
+
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/296895) in GitLab Free 13.9.
+
+To prevent users from publishing duplicate Maven packages, you can use the [GraphQl API](../../../api/graphql/reference/index.md#packagesettings) or the UI.
+
+In the UI:
+
+1. For your group, go to **Settings > Packages & Registries**.
+1. Expand the **Package Registry** section.
+1. Turn on the **Reject duplicates** toggle.
+1. Optional. To allow some duplicate packages, in the **Exceptions** box, enter a regex pattern that matches the names of packages you want to allow.
+
+Your changes are automatically saved.
+
 ## Install a package
 
 To install a package from the GitLab Package Registry, you must configure

spec/features/groups/settings/packages_and_registries_spec.rb

@@ -15,9 +15,9 @@ RSpec.describe 'Group Packages & Registries settings' do
     sign_in(user)
   end
 
-  context 'when the feature flag is off' do
+  context 'when packges feature is disabled on the group' do
     before do
-      stub_feature_flags(packages_and_registries_group_settings: false)
+      stub_packages_setting(enabled: false)
     end
 
     it 'the menu item is not visible' do
@@ -27,9 +27,15 @@ RSpec.describe 'Group Packages & Registries settings' do
 
       expect(settings_menu).not_to have_content 'Packages & Registries'
     end
+
+    it 'renders 404 when navigating to page' do
+      visit_settings_page
+
+      expect(page).to have_content('Not Found')
+    end
   end
 
-  context 'when the feature flag is on' do
+  context 'when packages feature is enabled on the group' do
     it 'the menu item is visible' do
       visit group_path(group)