Add the ability to ban users in the Admin Area

Banned users are blocked, and their issues are hidden.

Changelog: added

app/controllers/admin/users_controller.rb

@@ -370,7 +370,7 @@ class Admin::UsersController < Admin::ApplicationController
   end
 
   def check_ban_user_feature_flag
-    access_denied! unless Feature.enabled?(:ban_user_feature_flag)
+    access_denied! unless Feature.enabled?(:ban_user_feature_flag, default_enabled: :yaml)
   end
 
   def log_impersonation_event

app/graphql/types/issue_type.rb

@@ -169,7 +169,7 @@ module Types
     end
 
     def hidden?
-      object.hidden? if Feature.enabled?(:ban_user_feature_flag)
+      object.hidden? if Feature.enabled?(:ban_user_feature_flag, default_enabled: :yaml)
     end
 
     def escalation_status

app/helpers/issues_helper.rb

@@ -63,7 +63,7 @@ module IssuesHelper
   end
 
   def issue_hidden?(issue)
-    Feature.enabled?(:ban_user_feature_flag) && issue.hidden?
+    Feature.enabled?(:ban_user_feature_flag, default_enabled: :yaml) && issue.hidden?
   end
 
   def hidden_issue_icon(issue)

app/helpers/users_helper.rb

@@ -125,7 +125,7 @@ module UsersHelper
   end
 
   def ban_feature_available?
-    Feature.enabled?(:ban_user_feature_flag)
+    Feature.enabled?(:ban_user_feature_flag, default_enabled: :yaml)
   end
 
   def confirm_user_data(user)

app/models/issue.rb

@@ -143,7 +143,7 @@ class Issue < ApplicationRecord
   scope :confidential_only, -> { where(confidential: true) }
 
   scope :without_hidden, -> {
-    if Feature.enabled?(:ban_user_feature_flag)
+    if Feature.enabled?(:ban_user_feature_flag, default_enabled: :yaml)
       where('NOT EXISTS (?)', Users::BannedUser.select(1).where('issues.author_id = banned_users.user_id'))
     else
       all

config/feature_flags/development/ban_user_feature_flag.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/330667
 milestone: '13.12'
 type: development
 group: group::access
-default_enabled: false
+default_enabled: true

doc/user/admin_area/moderate_users.md

@@ -208,7 +208,13 @@ Users can also be activated using the [GitLab API](../../api/users.md#activate-u
 
 ## Ban and unban users
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/327353) in GitLab 14.2.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/327353) in GitLab 14.2 [with a flag](../../administration/feature_flags.md) named `ban_user_feature_flag`. Disabled by default.
+> - [Enabled by default](https://gitlab.com/gitlab-org/gitlab/-/issues/330667) in GitLab 14.8.
+
+FLAG:
+On self-managed GitLab, by default this feature is available.
+To hide the feature, ask an administrator to [disable the feature flag](../../administration/feature_flags.md) named `ban_user_feature_flag`.
+On GitLab.com, this feature is available to GitLab.com administrators only.
 
 GitLab administrators can ban and unban users. Banned users are blocked, and their issues are hidden.
 The banned user's comments are still displayed. Hiding a banned user's comments is [tracked in this issue](https://gitlab.com/gitlab-org/gitlab/-/issues/327356).