Merge remote-tracking branch 'upstream/master' into no-ivar-in-modules

* upstream/master: (507 commits)
  Add dropdowns documentation
  Convert migration to populate latest merge request ID into a background migration
  Set 0.69.0 instead of latest for codeclimate image
  De-duplicate background migration matchers defined in spec/support/migrations_helpers.rb
  Update database_debugging.md
  Update database_debugging.md
  Move installation of apps higher
  Change to Google Kubernetes Cluster and add internal links
  Add Ingress description from official docs
  Add info on creating your own k8s cluster from the cluster page
  Add info about the installed apps in the Cluster docs
  Resolve "lock/confidential issuable sidebar custom svg icons iteration"
  Update HA README.md to clarify GitLab support does not troubleshoot DRBD.
  Update license_finder to 3.1.1
  Make sure NotesActions#noteable returns a Noteable in the update action
  Cache the number of user SSH keys
  Adjust openid_connect_spec to use `raise_error`
  Resolve "Clicking on GPG verification badge jumps to top of the page"
  Add changelog for container repository path update
  Update container repository path reference
  ...

1 files changed, 48 insertions, 19 deletions

diff --git a/lib/api/groups.rb b/lib/api/groups.rb
index e817dcbbc4b..bcf2e6dae1d 100644
--- a/lib/api/groups.rb
+++ b/lib/api/groups.rb
@@ -25,22 +25,7 @@ module API
         optional :statistics, type: Boolean, default: false, desc: 'Include project statistics'
       end
 
-      def present_groups(groups, options = {})
-        options = options.reverse_merge(
-          with: Entities::Group,
-          current_user: current_user
-        )
-
-        groups = groups.with_statistics if options[:statistics]
-        present paginate(groups), options
-      end
-    end
-
-    resource :groups do
-      desc 'Get a groups list' do
-        success Entities::Group
-      end
-      params do
+      params :group_list_params do
         use :statistics_params
         optional :skip_groups, type: Array[Integer], desc: 'Array of group ids to exclude from list'
         optional :all_available, type: Boolean, desc: 'Show all group that you have access to'
@@ -50,14 +35,47 @@ module API
         optional :sort, type: String, values: %w[asc desc], default: 'asc', desc: 'Sort by asc (ascending) or desc (descending)'
         use :pagination
       end
-      get do
-        find_params = { all_available: params[:all_available], owned: params[:owned] }
+
+      def find_groups(params)
+        find_params = {
+          all_available: params[:all_available],
+          custom_attributes: params[:custom_attributes],
+          owned: params[:owned]
+        }
+        find_params[:parent] = find_group!(params[:id]) if params[:id]
+
         groups = GroupsFinder.new(current_user, find_params).execute
         groups = groups.search(params[:search]) if params[:search].present?
         groups = groups.where.not(id: params[:skip_groups]) if params[:skip_groups].present?
         groups = groups.reorder(params[:order_by] => params[:sort])
 
-        present_groups groups, statistics: params[:statistics] && current_user.admin?
+        groups
+      end
+
+      def present_groups(params, groups)
+        options = {
+          with: Entities::Group,
+          current_user: current_user,
+          statistics: params[:statistics] && current_user.admin?
+        }
+
+        groups = groups.with_statistics if options[:statistics]
+        present paginate(groups), options
+      end
+    end
+
+    resource :groups do
+      include CustomAttributesEndpoints
+
+      desc 'Get a groups list' do
+        success Entities::Group
+      end
+      params do
+        use :group_list_params
+      end
+      get do
+        groups = find_groups(params)
+        present_groups params, groups
       end
 
       desc 'Create a group. Available only for users who can create groups.' do
@@ -159,6 +177,17 @@ module API
         present paginate(projects), with: entity, current_user: current_user
       end
 
+      desc 'Get a list of subgroups in this group.' do
+        success Entities::Group
+      end
+      params do
+        use :group_list_params
+      end
+      get ":id/subgroups" do
+        groups = find_groups(params)
+        present_groups params, groups
+      end
+
       desc 'Transfer a project to the group namespace. Available only for admin.' do
         success Entities::GroupDetail
       end