use Gitlab::UserSettings directly as a singleton instead of including/extending it

app/controllers/admin/cohorts_controller.rb

 class Admin::CohortsController < Admin::ApplicationController
   def index
-    if current_application_settings.usage_ping_enabled
+    if Gitlab::CurrentSettings.usage_ping_enabled
       cohorts_results = Rails.cache.fetch('cohorts', expires_in: 1.day) do
         CohortsService.new.execute
       end

app/controllers/application_controller.rb

@@ -2,7 +2,6 @@ require 'gon'
 require 'fogbugz'
 
 class ApplicationController < ActionController::Base
-  include Gitlab::CurrentSettings
   include Gitlab::GonHelper
   include GitlabRoutingHelper
   include PageLayoutHelper
@@ -28,7 +27,7 @@ class ApplicationController < ActionController::Base
 
   protect_from_forgery with: :exception
 
-  helper_method :can?, :current_application_settings
+  helper_method :can?
   helper_method :import_sources_enabled?, :github_import_enabled?, :gitea_import_enabled?, :github_import_configured?, :gitlab_import_enabled?, :gitlab_import_configured?, :bitbucket_import_enabled?, :bitbucket_import_configured?, :google_code_import_enabled?, :fogbugz_import_enabled?, :git_import_enabled?, :gitlab_project_import_enabled?
 
   rescue_from Encoding::CompatibilityError do |exception|
@@ -120,7 +119,7 @@ class ApplicationController < ActionController::Base
   end
 
   def after_sign_out_path_for(resource)
-    current_application_settings.after_sign_out_path.presence || new_user_session_path
+    Gitlab::CurrentSettings.after_sign_out_path.presence || new_user_session_path
   end
 
   def can?(object, action, subject = :global)
@@ -268,15 +267,15 @@ class ApplicationController < ActionController::Base
   end
 
   def import_sources_enabled?
-    !current_application_settings.import_sources.empty?
+    !Gitlab::CurrentSettings.import_sources.empty?
   end
 
   def github_import_enabled?
-    current_application_settings.import_sources.include?('github')
+    Gitlab::CurrentSettings.import_sources.include?('github')
   end
 
   def gitea_import_enabled?
-    current_application_settings.import_sources.include?('gitea')
+    Gitlab::CurrentSettings.import_sources.include?('gitea')
   end
 
   def github_import_configured?
@@ -284,7 +283,7 @@ class ApplicationController < ActionController::Base
   end
 
   def gitlab_import_enabled?
-    request.host != 'gitlab.com' && current_application_settings.import_sources.include?('gitlab')
+    request.host != 'gitlab.com' && Gitlab::CurrentSettings.import_sources.include?('gitlab')
   end
 
   def gitlab_import_configured?
@@ -292,7 +291,7 @@ class ApplicationController < ActionController::Base
   end
 
   def bitbucket_import_enabled?
-    current_application_settings.import_sources.include?('bitbucket')
+    Gitlab::CurrentSettings.import_sources.include?('bitbucket')
   end
 
   def bitbucket_import_configured?
@@ -300,19 +299,19 @@ class ApplicationController < ActionController::Base
   end
 
   def google_code_import_enabled?
-    current_application_settings.import_sources.include?('google_code')
+    Gitlab::CurrentSettings.import_sources.include?('google_code')
   end
 
   def fogbugz_import_enabled?
-    current_application_settings.import_sources.include?('fogbugz')
+    Gitlab::CurrentSettings.import_sources.include?('fogbugz')
   end
 
   def git_import_enabled?
-    current_application_settings.import_sources.include?('git')
+    Gitlab::CurrentSettings.import_sources.include?('git')
   end
 
   def gitlab_project_import_enabled?
-    current_application_settings.import_sources.include?('gitlab_project')
+    Gitlab::CurrentSettings.import_sources.include?('gitlab_project')
   end
 
   # U2F (universal 2nd factor) devices need a unique identifier for the application

app/controllers/concerns/enforces_two_factor_authentication.rb

@@ -20,13 +20,13 @@ module EnforcesTwoFactorAuthentication
   end
 
   def two_factor_authentication_required?
-    current_application_settings.require_two_factor_authentication? ||
+    Gitlab::CurrentSettings.require_two_factor_authentication? ||
       current_user.try(:require_two_factor_authentication_from_group?)
   end
 
   def two_factor_authentication_reason(global: -> {}, group: -> {})
     if two_factor_authentication_required?
-      if current_application_settings.require_two_factor_authentication?
+      if Gitlab::CurrentSettings.require_two_factor_authentication?
         global.call
       else
         groups = current_user.expanded_groups_requiring_two_factor_authentication.reorder(name: :asc)
@@ -36,7 +36,7 @@ module EnforcesTwoFactorAuthentication
   end
 
   def two_factor_grace_period
-    periods = [current_application_settings.two_factor_grace_period]
+    periods = [Gitlab::CurrentSettings.two_factor_grace_period]
     periods << current_user.two_factor_grace_period if current_user.try(:require_two_factor_authentication_from_group?)
     periods.min
   end

app/controllers/concerns/requires_whitelisted_monitoring_client.rb

 module RequiresWhitelistedMonitoringClient
   extend ActiveSupport::Concern
 
-  include Gitlab::CurrentSettings
-
   included do
     before_action :validate_ip_whitelisted_or_valid_token!
   end
@@ -26,7 +24,7 @@ module RequiresWhitelistedMonitoringClient
     token.present? &&
       ActiveSupport::SecurityUtils.variable_size_secure_compare(
         token,
-        current_application_settings.health_check_access_token
+        Gitlab::CurrentSettings.health_check_access_token
       )
   end
 

app/controllers/invites_controller.rb

@@ -51,7 +51,7 @@ class InvitesController < ApplicationController
     return if current_user
 
     notice = "To accept this invitation, sign in"
-    notice << " or create an account" if current_application_settings.allow_signup?
+    notice << " or create an account" if Gitlab::CurrentSettings.allow_signup?
     notice << "."
 
     store_location_for :user, request.fullpath

app/controllers/koding_controller.rb

@@ -10,6 +10,6 @@ class KodingController < ApplicationController
   private
 
   def check_integration!
-    render_404 unless current_application_settings.koding_enabled?
+    render_404 unless Gitlab::CurrentSettings.koding_enabled?
   end
 end

app/controllers/oauth/applications_controller.rb

 class Oauth::ApplicationsController < Doorkeeper::ApplicationsController
-  include Gitlab::CurrentSettings
   include Gitlab::GonHelper
   include PageLayoutHelper
   include OauthApplications
@@ -31,7 +30,7 @@ class Oauth::ApplicationsController < Doorkeeper::ApplicationsController
   private
 
   def verify_user_oauth_applications_enabled
-    return if current_application_settings.user_oauth_applications?
+    return if Gitlab::CurrentSettings.user_oauth_applications?
 
     redirect_to profile_path
   end

app/controllers/omniauth_callbacks_controller.rb

@@ -145,7 +145,7 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController
     label = Gitlab::OAuth::Provider.label_for(oauth['provider'])
     message = "Signing in using your #{label} account without a pre-existing GitLab account is not allowed."
 
-    if current_application_settings.allow_signup?
+    if Gitlab::CurrentSettings.allow_signup?
       message << " Create a GitLab account first, and then connect it to your #{label} account."
     end
 

app/controllers/passwords_controller.rb

 class PasswordsController < Devise::PasswordsController
-  include Gitlab::CurrentSettings
-
   skip_before_action :require_no_authentication, only: [:edit, :update]
 
   before_action :resource_from_email, only: [:create]
@@ -46,7 +44,7 @@ class PasswordsController < Devise::PasswordsController
     if resource
       return if resource.allow_password_authentication?
     else
-      return if current_application_settings.password_authentication_enabled?
+      return if Gitlab::CurrentSettings.password_authentication_enabled?
     end
 
     redirect_to after_sending_reset_password_instructions_path_for(resource_name),

app/controllers/projects_controller.rb

@@ -394,7 +394,7 @@ class ProjectsController < Projects::ApplicationController
   end
 
   def project_export_enabled
-    render_404 unless current_application_settings.project_export_enabled?
+    render_404 unless Gitlab::CurrentSettings.project_export_enabled?
   end
 
   def redirect_git_extension

app/controllers/root_controller.rb

@@ -23,7 +23,7 @@ class RootController < Dashboard::ProjectsController
 
   def redirect_unlogged_user
     if redirect_to_home_page_url?
-      redirect_to(current_application_settings.home_page_url)
+      redirect_to(Gitlab::CurrentSettings.home_page_url)
     else
       redirect_to(new_user_session_path)
     end
@@ -48,9 +48,9 @@ class RootController < Dashboard::ProjectsController
   def redirect_to_home_page_url?
     # If user is not signed-in and tries to access root_path - redirect him to landing page
     # Don't redirect to the default URL to prevent endless redirections
-    return false unless current_application_settings.home_page_url.present?
+    return false unless Gitlab::CurrentSettings.home_page_url.present?
 
-    home_page_url = current_application_settings.home_page_url.chomp('/')
+    home_page_url = Gitlab::CurrentSettings.home_page_url.chomp('/')
     root_urls = [Gitlab.config.gitlab['url'].chomp('/'), root_url.chomp('/')]
 
     root_urls.exclude?(home_page_url)

app/helpers/application_settings_helper.rb

 module ApplicationSettingsHelper
   extend self
 
-  include Gitlab::CurrentSettings
-
   delegate  :allow_signup?,
             :gravatar_enabled?,
             :password_authentication_enabled_for_web?,
             :akismet_enabled?,
             :koding_enabled?,
-            to: :current_application_settings
+            to: :'Gitlab::CurrentSettings.current_application_settings'
 
   def user_oauth_applications?
-    current_application_settings.user_oauth_applications
+    Gitlab::CurrentSettings.user_oauth_applications
   end
 
   def allowed_protocols_present?
-    current_application_settings.enabled_git_access_protocol.present?
+    Gitlab::CurrentSettings.enabled_git_access_protocol.present?
   end
 
   def enabled_protocol
-    case current_application_settings.enabled_git_access_protocol
+    case Gitlab::CurrentSettings.enabled_git_access_protocol
     when 'http'
       gitlab_config.protocol
     when 'ssh'
@@ -57,7 +55,7 @@ module ApplicationSettingsHelper
   # toggle button effect.
   def import_sources_checkboxes(help_block_id)
     Gitlab::ImportSources.options.map do |name, source|
-      checked = current_application_settings.import_sources.include?(source)
+      checked = Gitlab::CurrentSettings.import_sources.include?(source)
       css_class = checked ? 'active' : ''
       checkbox_name = 'application_setting[import_sources][]'
 
@@ -72,7 +70,7 @@ module ApplicationSettingsHelper
 
   def oauth_providers_checkboxes
     button_based_providers.map do |source|
-      disabled = current_application_settings.disabled_oauth_sign_in_sources.include?(source.to_s)
+      disabled = Gitlab::CurrentSettings.disabled_oauth_sign_in_sources.include?(source.to_s)
       css_class = 'btn'
       css_class << ' active' unless disabled
       checkbox_name = 'application_setting[enabled_oauth_sign_in_sources][]'

app/helpers/auth_helper.rb

 module AuthHelper
-  include Gitlab::CurrentSettings
-
   PROVIDERS_WITH_ICONS = %w(twitter github gitlab bitbucket google_oauth2 facebook azure_oauth2 authentiq).freeze
   FORM_BASED_PROVIDERS = [/\Aldap/, 'crowd'].freeze
 
@@ -41,7 +39,7 @@ module AuthHelper
   end
 
   def enabled_button_based_providers
-    disabled_providers = current_application_settings.disabled_oauth_sign_in_sources || []
+    disabled_providers = Gitlab::CurrentSettings.disabled_oauth_sign_in_sources || []
 
     button_based_providers.map(&:to_s) - disabled_providers
   end

app/helpers/projects_helper.rb

 module ProjectsHelper
-  include Gitlab::CurrentSettings
-
   def link_to_project(project)
     link_to [project.namespace.becomes(Namespace), project], title: h(project.name) do
       title = content_tag(:span, project.name, class: 'project-name')
@@ -214,7 +212,7 @@ module ProjectsHelper
       project.cache_key,
       controller.controller_name,
       controller.action_name,
-      current_application_settings.cache_key,
+      Gitlab::CurrentSettings.cache_key,
       'v2.5'
     ]
 
@@ -447,10 +445,10 @@ module ProjectsHelper
 
       path = "#{import_path}?repo=#{repo}&branch=#{branch}&sha=#{sha}"
 
-      return URI.join(current_application_settings.koding_url, path).to_s
+      return URI.join(Gitlab::CurrentSettings.koding_url, path).to_s
     end
 
-    current_application_settings.koding_url
+    Gitlab::CurrentSettings.koding_url
   end
 
   def contribution_guide_path(project)
@@ -559,7 +557,7 @@ module ProjectsHelper
   def restricted_levels
     return [] if current_user.admin?
 
-    current_application_settings.restricted_visibility_levels || []
+    Gitlab::CurrentSettings.restricted_visibility_levels || []
   end
 
   def project_permissions_settings(project)

app/helpers/version_check_helper.rb

 module VersionCheckHelper
   def version_status_badge
-    if Rails.env.production? && current_application_settings.version_check_enabled
+    if Rails.env.production? && Gitlab::CurrentSettings.version_check_enabled
       image_url = VersionCheck.new.url
       image_tag image_url, class: 'js-version-status-badge'
     end

app/helpers/visibility_level_helper.rb

@@ -151,12 +151,12 @@ module VisibilityLevelHelper
   def restricted_visibility_levels(show_all = false)
     return [] if current_user.admin? && !show_all
 
-    current_application_settings.restricted_visibility_levels || []
+    Gitlab::CurrentSettings.restricted_visibility_levels || []
   end
 
   delegate  :default_project_visibility,
             :default_group_visibility,
-            to: :current_application_settings
+            to: :'Gitlab::CurrentSettings.current_application_settings'
 
   def disallowed_visibility_level?(form_model, level)
     return false unless form_model.respond_to?(:visibility_level_allowed?)

app/mailers/abuse_report_mailer.rb

 class AbuseReportMailer < BaseMailer
-  include Gitlab::CurrentSettings
-
   def notify(abuse_report_id)
     return unless deliverable?
 
     @abuse_report = AbuseReport.find(abuse_report_id)
 
     mail(
-      to:       current_application_settings.admin_notification_email,
+      to:       Gitlab::CurrentSettings.admin_notification_email,
       subject:  "#{@abuse_report.user.name} (#{@abuse_report.user.username}) was reported for abuse"
     )
   end
@@ -15,6 +13,6 @@ class AbuseReportMailer < BaseMailer
   private
 
   def deliverable?
-    current_application_settings.admin_notification_email.present?
+    Gitlab::CurrentSettings.admin_notification_email.present?
   end
 end

app/mailers/base_mailer.rb

 class BaseMailer < ActionMailer::Base
-  include Gitlab::CurrentSettings
-
   around_action :render_with_default_locale
 
   helper ApplicationHelper
   helper MarkupHelper
 
   attr_accessor :current_user
-  helper_method :current_user, :can?, :current_application_settings
+  helper_method :current_user, :can?
 
   default from:     proc { default_sender_address.format }
   default reply_to: proc { default_reply_to_address.format }

app/models/clusters/platforms/kubernetes.rb

 module Clusters
   module Platforms
     class Kubernetes < ActiveRecord::Base
-      include Gitlab::CurrentSettings
       include Gitlab::Kubernetes
       include ReactiveCaching
 
@@ -169,7 +168,7 @@ module Clusters
         {
           token: token,
           ca_pem: ca_pem,
-          max_session_time: current_application_settings.terminal_max_session_time
+          max_session_time: Gitlab::CurrentSettings.terminal_max_session_time
         }
       end
 

app/models/issue_assignee.rb

 class IssueAssignee < ActiveRecord::Base
-  extend Gitlab::CurrentSettings
-
   belongs_to :issue
   belongs_to :assignee, class_name: "User", foreign_key: :user_id
 end

app/models/key.rb

 require 'digest/md5'
 
 class Key < ActiveRecord::Base
-  include Gitlab::CurrentSettings
   include AfterCommitQueue
   include Sortable
 
@@ -104,7 +103,7 @@ class Key < ActiveRecord::Base
   end
 
   def key_meets_restrictions
-    restriction = current_application_settings.key_restriction_for(public_key.type)
+    restriction = Gitlab::CurrentSettings.key_restriction_for(public_key.type)
 
     if restriction == ApplicationSetting::FORBIDDEN_KEY_VALUE
       errors.add(:key, forbidden_key_type_message)
@@ -115,7 +114,7 @@ class Key < ActiveRecord::Base
 
   def forbidden_key_type_message
     allowed_types =
-      current_application_settings
+      Gitlab::CurrentSettings
         .allowed_key_types
         .map(&:upcase)
         .to_sentence(last_word_connector: ', or ', two_words_connector: ' or ')

app/models/namespace.rb

@@ -2,7 +2,6 @@ class Namespace < ActiveRecord::Base
   include CacheMarkdownField
   include Sortable
   include Gitlab::ShellAdapter
-  include Gitlab::CurrentSettings
   include Gitlab::VisibilityLevel
   include Routable
   include AfterCommitQueue

app/models/note.rb

@@ -3,7 +3,6 @@
 # A note of this type is never resolvable.
 class Note < ActiveRecord::Base
   extend ActiveModel::Naming
-  include Gitlab::CurrentSettings
   include Participable
   include Mentionable
   include Awardable
@@ -196,7 +195,7 @@ class Note < ActiveRecord::Base
   end
 
   def max_attachment_size
-    current_application_settings.max_attachment_size.megabytes.to_i
+    Gitlab::CurrentSettings.max_attachment_size.megabytes.to_i
   end
 
   def hook_attrs

app/models/project.rb

@@ -4,7 +4,6 @@ class Project < ActiveRecord::Base
   include Gitlab::ConfigHelper
   include Gitlab::ShellAdapter
   include Gitlab::VisibilityLevel
-  include Gitlab::CurrentSettings
   include AccessRequestable
   include Avatarable
   include CacheMarkdownField
@@ -23,7 +22,6 @@ class Project < ActiveRecord::Base
   include ::Gitlab::Utils::StrongMemoize
 
   extend Gitlab::ConfigHelper
-  extend Gitlab::CurrentSettings
 
   BoardLimitExceeded = Class.new(StandardError)
 
@@ -51,8 +49,8 @@ class Project < ActiveRecord::Base
   default_value_for :visibility_level, gitlab_config_features.visibility_level
   default_value_for :resolve_outdated_diff_discussions, false
   default_value_for :container_registry_enabled, gitlab_config_features.container_registry
-  default_value_for(:repository_storage) { current_application_settings.pick_repository_storage }
-  default_value_for(:shared_runners_enabled) { current_application_settings.shared_runners_enabled }
+  default_value_for(:repository_storage) { Gitlab::CurrentSettings.pick_repository_storage }
+  default_value_for(:shared_runners_enabled) { Gitlab::CurrentSettings.shared_runners_enabled }
   default_value_for :issues_enabled, gitlab_config_features.issues
   default_value_for :merge_requests_enabled, gitlab_config_features.merge_requests
   default_value_for :builds_enabled, gitlab_config_features.builds
@@ -486,14 +484,14 @@ class Project < ActiveRecord::Base
 
   def auto_devops_enabled?
     if auto_devops&.enabled.nil?
-      current_application_settings.auto_devops_enabled?
+      Gitlab::CurrentSettings.auto_devops_enabled?
     else
       auto_devops.enabled?
     end
   end
 
   def has_auto_devops_implicitly_disabled?
-    auto_devops&.enabled.nil? && !current_application_settings.auto_devops_enabled?
+    auto_devops&.enabled.nil? && !Gitlab::CurrentSettings.auto_devops_enabled?
   end
 
   def empty_repo?
@@ -1471,14 +1469,14 @@ class Project < ActiveRecord::Base
     # Ensure HEAD points to the default branch in case it is not master
     change_head(default_branch)
 
-    if current_application_settings.default_branch_protection != Gitlab::Access::PROTECTION_NONE && !ProtectedBranch.protected?(self, default_branch)
+    if Gitlab::CurrentSettings.default_branch_protection != Gitlab::Access::PROTECTION_NONE && !ProtectedBranch.protected?(self, default_branch)
       params = {
         name: default_branch,
         push_access_levels_attributes: [{
-          access_level: current_application_settings.default_branch_protection == Gitlab::Access::PROTECTION_DEV_CAN_PUSH ? Gitlab::Access::DEVELOPER : Gitlab::Access::MASTER
+          access_level: Gitlab::CurrentSettings.default_branch_protection == Gitlab::Access::PROTECTION_DEV_CAN_PUSH ? Gitlab::Access::DEVELOPER : Gitlab::Access::MASTER
         }],
         merge_access_levels_attributes: [{
-          access_level: current_application_settings.default_branch_protection == Gitlab::Access::PROTECTION_DEV_CAN_MERGE ? Gitlab::Access::DEVELOPER : Gitlab::Access::MASTER
+          access_level: Gitlab::CurrentSettings.default_branch_protection == Gitlab::Access::PROTECTION_DEV_CAN_MERGE ? Gitlab::Access::DEVELOPER : Gitlab::Access::MASTER
         }]
       }
 
@@ -1773,7 +1771,7 @@ class Project < ActiveRecord::Base
   end
 
   def use_hashed_storage
-    if self.new_record? && current_application_settings.hashed_storage_enabled
+    if self.new_record? && Gitlab::CurrentSettings.hashed_storage_enabled
       self.storage_version = LATEST_STORAGE_VERSION
     end
   end

app/models/project_services/kubernetes_service.rb

@@ -4,7 +4,6 @@
 # After we've migrated data, we'll remove KubernetesService. This would happen in a few months.
 # If you're modyfiyng this class, please note that you should update the same change in Clusters::Platforms::Kubernetes.
 class KubernetesService < DeploymentService
-  include Gitlab::CurrentSettings
   include Gitlab::Kubernetes
   include ReactiveCaching
 
@@ -231,7 +230,7 @@ class KubernetesService < DeploymentService
     {
       token: token,
       ca_pem: ca_pem,
-      max_session_time: current_application_settings.terminal_max_session_time
+      max_session_time: Gitlab::CurrentSettings.terminal_max_session_time
     }
   end
 

app/models/protected_branch.rb

@@ -2,8 +2,6 @@ class ProtectedBranch < ActiveRecord::Base
   include Gitlab::ShellAdapter
   include ProtectedRef
 
-  extend Gitlab::CurrentSettings
-
   protected_ref_access_levels :merge, :push
 
   # Check if branch name is marked as protected in the system
@@ -16,7 +14,7 @@ class ProtectedBranch < ActiveRecord::Base
   end
 
   def self.default_branch_protected?
-    current_application_settings.default_branch_protection == Gitlab::Access::PROTECTION_FULL ||
-      current_application_settings.default_branch_protection == Gitlab::Access::PROTECTION_DEV_CAN_MERGE
+    Gitlab::CurrentSettings.default_branch_protection == Gitlab::Access::PROTECTION_FULL ||
+      Gitlab::CurrentSettings.default_branch_protection == Gitlab::Access::PROTECTION_DEV_CAN_MERGE
   end
 end

app/models/snippet.rb

@@ -11,8 +11,6 @@ class Snippet < ActiveRecord::Base
   include Editable
   include Gitlab::SQL::Pattern
 
-  extend Gitlab::CurrentSettings
-
   cache_markdown_field :title, pipeline: :single_line
   cache_markdown_field :description
   cache_markdown_field :content
@@ -28,7 +26,7 @@ class Snippet < ActiveRecord::Base
     default_content_html_invalidator || file_name_changed?
   end
 
-  default_value_for(:visibility_level) { current_application_settings.default_snippet_visibility }
+  default_value_for(:visibility_level) { Gitlab::CurrentSettings.default_snippet_visibility }
 
   belongs_to :author, class_name: 'User'
   belongs_to :project

app/models/user.rb

@@ -2,10 +2,8 @@ require 'carrierwave/orm/activerecord'
 
 class User < ActiveRecord::Base
   extend Gitlab::ConfigHelper
-  extend Gitlab::CurrentSettings
 
   include Gitlab::ConfigHelper
-  include Gitlab::CurrentSettings
   include Gitlab::SQL::Pattern
   include AfterCommitQueue
   include Avatarable
@@ -30,7 +28,7 @@ class User < ActiveRecord::Base
   add_authentication_token_field :rss_token
 
   default_value_for :admin, false
-  default_value_for(:external) { current_application_settings.user_default_external }
+  default_value_for(:external) { Gitlab::CurrentSettings.user_default_external }
   default_value_for :can_create_group, gitlab_config.default_can_create_group
   default_value_for :can_create_team, false
   default_value_for :hide_no_ssh_key, false
@@ -660,11 +658,11 @@ class User < ActiveRecord::Base
   end
 
   def allow_password_authentication_for_web?
-    current_application_settings.password_authentication_enabled_for_web? && !ldap_user?
+    Gitlab::CurrentSettings.password_authentication_enabled_for_web? && !ldap_user?
   end
 
   def allow_password_authentication_for_git?
-    current_application_settings.password_authentication_enabled_for_git? && !ldap_user?
+    Gitlab::CurrentSettings.password_authentication_enabled_for_git? && !ldap_user?
   end
 
   def can_change_username?
@@ -792,7 +790,7 @@ class User < ActiveRecord::Base
     # without this safeguard!
     return unless has_attribute?(:projects_limit) && projects_limit.nil?
 
-    self.projects_limit = current_application_settings.default_projects_limit
+    self.projects_limit = Gitlab::CurrentSettings.default_projects_limit
   end
 
   def requires_ldap_check?
@@ -1215,7 +1213,7 @@ class User < ActiveRecord::Base
     else
       # Only revert these back to the default if they weren't specifically changed in this update.
       self.can_create_group = gitlab_config.default_can_create_group unless can_create_group_changed?
-      self.projects_limit = current_application_settings.default_projects_limit unless projects_limit_changed?
+      self.projects_limit = Gitlab::CurrentSettings.default_projects_limit unless projects_limit_changed?
     end
   end
 
@@ -1223,15 +1221,15 @@ class User < ActiveRecord::Base
     valid = true
     error = nil
 
-    if current_application_settings.domain_blacklist_enabled?
-      blocked_domains = current_application_settings.domain_blacklist
+    if Gitlab::CurrentSettings.domain_blacklist_enabled?
+      blocked_domains = Gitlab::CurrentSettings.domain_blacklist
       if domain_matches?(blocked_domains, email)
         error = 'is not from an allowed domain.'
         valid = false
       end
     end
 
-    allowed_domains = current_application_settings.domain_whitelist
+    allowed_domains = Gitlab::CurrentSettings.domain_whitelist
     unless allowed_domains.blank?
       if domain_matches?(allowed_domains, email)
         valid = true

app/services/akismet_service.rb

 class AkismetService
-  include Gitlab::CurrentSettings
-
   attr_accessor :owner, :text, :options
 
   def initialize(owner, text, options = {})
@@ -41,12 +39,12 @@ class AkismetService
   private
 
   def akismet_client
-    @akismet_client ||= ::Akismet::Client.new(current_application_settings.akismet_api_key,
+    @akismet_client ||= ::Akismet::Client.new(Gitlab::CurrentSettings.akismet_api_key,
                                               Gitlab.config.gitlab.url)
   end
 
   def akismet_enabled?
-    current_application_settings.akismet_enabled
+    Gitlab::CurrentSettings.akismet_enabled
   end
 
   def submit(type)

app/services/auth/container_registry_authentication_service.rb

 module Auth
   class ContainerRegistryAuthenticationService < BaseService
-    extend Gitlab::CurrentSettings
-
     AUDIENCE = 'container_registry'.freeze
 
     def execute(authentication_abilities:)
@@ -32,7 +30,7 @@ module Auth
     end
 
     def self.token_expire_at
-      Time.now + current_application_settings.container_registry_token_expire_delay.minutes
+      Time.now + Gitlab::CurrentSettings.container_registry_token_expire_delay.minutes
     end
 
     private

app/services/base_service.rb

 class BaseService
   include Gitlab::Allowable
-  include Gitlab::CurrentSettings
 
   attr_accessor :project, :current_user, :params
 

app/services/ci/register_job_service.rb

@@ -2,8 +2,6 @@ module Ci
   # This class responsible for assigning
   # proper pending build to runner on runner API request
   class RegisterJobService
-    include Gitlab::CurrentSettings
-
     attr_reader :runner
 
     Result = Struct.new(:build, :valid?)

app/services/git_push_service.rb

 class GitPushService < BaseService
   attr_accessor :push_data, :push_commits
-  include Gitlab::CurrentSettings
   include Gitlab::Access
 
   # The N most recent commits to process in a single push payload.

app/services/gravatar_service.rb

 class GravatarService
-  include Gitlab::CurrentSettings
-
   def execute(email, size = nil, scale = 2, username: nil)
-    return unless current_application_settings.gravatar_enabled?
+    return unless Gitlab::CurrentSettings.gravatar_enabled?
 
     identifier = email.presence || username.presence
     return unless identifier

app/services/projects/housekeeping_service.rb

@@ -7,8 +7,6 @@
 #
 module Projects
   class HousekeepingService < BaseService
-    include Gitlab::CurrentSettings
-
     # Timeout set to 24h
     LEASE_TIMEOUT = 86400
 
@@ -83,19 +81,19 @@ module Projects
     end
 
     def housekeeping_enabled?
-      current_application_settings.housekeeping_enabled
+      Gitlab::CurrentSettings.housekeeping_enabled
     end
 
     def gc_period
-      current_application_settings.housekeeping_gc_period
+      Gitlab::CurrentSettings.housekeeping_gc_period
     end
 
     def full_repack_period
-      current_application_settings.housekeeping_full_repack_period
+      Gitlab::CurrentSettings.housekeeping_full_repack_period
     end
 
     def repack_period
-      current_application_settings.housekeeping_incremental_repack_period
+      Gitlab::CurrentSettings.housekeeping_incremental_repack_period
     end
   end
 end

app/services/projects/update_pages_service.rb

 module Projects
   class UpdatePagesService < BaseService
-    include Gitlab::CurrentSettings
-
     BLOCK_SIZE = 32.kilobytes
     MAX_SIZE = 1.terabyte
     SITE_PATH = 'public/'.freeze
@@ -134,7 +132,7 @@ module Projects
     end
 
     def max_size
-      max_pages_size = current_application_settings.max_pages_size.megabytes
+      max_pages_size = Gitlab::CurrentSettings.max_pages_size.megabytes
 
       return MAX_SIZE if max_pages_size.zero?
 

app/services/projects/update_service.rb

@@ -34,7 +34,7 @@ module Projects
     def run_auto_devops_pipeline?
       return false if project.repository.gitlab_ci_yml || !project.auto_devops.previous_changes.include?('enabled')
 
-      project.auto_devops.enabled? || (project.auto_devops.enabled.nil? && current_application_settings.auto_devops_enabled?)
+      project.auto_devops.enabled? || (project.auto_devops.enabled.nil? && Gitlab::CurrentSettings.auto_devops_enabled?)
     end
 
     private

app/services/submit_usage_ping_service.rb

@@ -11,10 +11,8 @@ class SubmitUsagePingService
                percentage_projects_prometheus_active leader_service_desk_issues instance_service_desk_issues
                percentage_service_desk_issues].freeze
 
-  include Gitlab::CurrentSettings
-
   def execute
-    return false unless current_application_settings.usage_ping_enabled?
+    return false unless Gitlab::CurrentSettings.usage_ping_enabled?
 
     response = HTTParty.post(
       URL,

app/services/upload_service.rb

 class UploadService
-  include Gitlab::CurrentSettings
-
   def initialize(model, file, uploader_class = FileUploader)
     @model, @file, @uploader_class = model, file, uploader_class
   end
@@ -17,6 +15,6 @@ class UploadService
   private
 
   def max_attachment_size
-    current_application_settings.max_attachment_size.megabytes.to_i
+    Gitlab::CurrentSettings.max_attachment_size.megabytes.to_i
   end
 end

app/services/users/build_service.rb

 module Users
   class BuildService < BaseService
-    include Gitlab::CurrentSettings
-
     def initialize(current_user, params = {})
       @current_user = current_user
       @params = params.dup
@@ -34,7 +32,7 @@ module Users
     private
 
     def can_create_user?
-      (current_user.nil? && current_application_settings.allow_signup?) || current_user&.admin?
+      (current_user.nil? && Gitlab::CurrentSettings.allow_signup?) || current_user&.admin?
     end
 
     # Allowed params for creating a user (admins only)
@@ -102,7 +100,7 @@ module Users
     end
 
     def skip_user_confirmation_email_from_setting
-      !current_application_settings.send_user_confirmation_email
+      !Gitlab::CurrentSettings.send_user_confirmation_email
     end
   end
 end

app/views/admin/conversational_development_index/show.html.haml

@@ -6,7 +6,7 @@
     = render 'callout'
 
   .prepend-top-default
-  - if !current_application_settings.usage_ping_enabled
+  - if !Gitlab::CurrentSettings.usage_ping_enabled
     = render 'disabled'
   - elsif @metric.blank?
     = render 'no_data'

app/views/admin/dashboard/index.html.haml

@@ -119,7 +119,7 @@
           .well-segment.admin-well
             %h4
               Components
-              - if current_application_settings.version_check_enabled
+              - if Gitlab::CurrentSettings.version_check_enabled
                 .pull-right
                   = version_status_badge
             %p

app/views/admin/health_check/show.html.haml

@@ -8,7 +8,7 @@
     .pull-left
       %p
     #{ s_('HealthCheck|Access token is') }
-    %code#health-check-token= current_application_settings.health_check_access_token
+    %code#health-check-token= Gitlab::CurrentSettings.health_check_access_token
     .prepend-top-10
       = button_to _("Reset health check access token"), reset_health_check_token_admin_application_settings_path,
         method: :put, class: 'btn btn-default',
@@ -18,11 +18,11 @@
     = link_to s_('More information is available|here'), help_page_path('user/admin_area/monitoring/health_check')
     %ul
       %li
-        %code= readiness_url(token: current_application_settings.health_check_access_token)
+        %code= readiness_url(token: Gitlab::CurrentSettings.health_check_access_token)
       %li
-        %code= liveness_url(token: current_application_settings.health_check_access_token)
+        %code= liveness_url(token: Gitlab::CurrentSettings.health_check_access_token)
       %li
-        %code= metrics_url(token: current_application_settings.health_check_access_token)
+        %code= metrics_url(token: Gitlab::CurrentSettings.health_check_access_token)
 
   %hr
   .panel.panel-default

app/views/admin/runners/index.html.haml

@@ -36,7 +36,7 @@
           data: { confirm: _("Are you sure you want to reset registration token?") }
 
   = render partial: 'ci/runner/how_to_setup_runner',
-           locals: { registration_token: current_application_settings.runners_registration_token,
+           locals: { registration_token: Gitlab::CurrentSettings.runners_registration_token,
                      type: 'shared' }
 
   .append-bottom-20.clearfix

app/views/devise/confirmations/almost_there.haml

@@ -4,9 +4,9 @@
   %p.lead.append-bottom-20
     Please check your email to confirm your account
   %hr
-- if current_application_settings.after_sign_up_text.present?
+- if Gitlab::CurrentSettings.after_sign_up_text.present?
   .well-confirmation.text-center
-    = markdown_field(current_application_settings, :after_sign_up_text)
+    = markdown_field(Gitlab::CurrentSettings, :after_sign_up_text)
 %p.text-center
   No confirmation email received? Please check your spam folder or
 .append-bottom-20.prepend-top-20.text-center

app/views/help/index.html.haml

 = webpack_bundle_tag 'docs'
 
 %div
-- if current_application_settings.help_page_text.present?
-  = markdown_field(current_application_settings, :help_page_text)
+- if Gitlab::CurrentSettings.help_page_text.present?
+  = markdown_field(Gitlab::CurrentSettings.current_application_settings, :help_page_text)
   %hr
 
 %h1
@@ -14,7 +14,7 @@
     = version_status_badge
   %hr
 
-- unless current_application_settings.help_page_hide_commercial_content?
+- unless Gitlab::CurrentSettings.help_page_hide_commercial_content?
   %p.slead
     GitLab is open source software to collaborate on code.
     %br
@@ -46,6 +46,6 @@
         %li
           %button.btn-blank.btn-link.js-trigger-shortcut{ type: 'button' }
             Use shortcuts
-        - unless current_application_settings.help_page_hide_commercial_content?
+        - unless Gitlab::CurrentSettings.help_page_hide_commercial_content?
           %li= link_to 'Get a support subscription', 'https://about.gitlab.com/pricing/'
           %li= link_to 'Compare GitLab editions', 'https://about.gitlab.com/features/#compare'

app/views/koding/index.html.haml

@@ -3,4 +3,4 @@
     = icon('circle', class: 'cgreen')
     Integration is active for
     = link_to koding_project_url, target: '_blank', rel: 'noopener noreferrer' do
-      #{current_application_settings.koding_url}
+      #{Gitlab::CurrentSettings.koding_url}

app/views/layouts/_head.html.haml

@@ -41,7 +41,7 @@
   = webpack_bundle_tag "webpack_runtime"
   = webpack_bundle_tag "common"
   = webpack_bundle_tag "main"
-  = webpack_bundle_tag "raven" if current_application_settings.clientside_sentry_enabled
+  = webpack_bundle_tag "raven" if Gitlab::CurrentSettings.clientside_sentry_enabled
   = webpack_bundle_tag "test" if Rails.env.test?
 
   - if content_for?(:page_specific_javascripts)

app/views/layouts/devise.html.haml

@@ -26,8 +26,8 @@
                   Perform code reviews and enhance collaboration with merge requests.
                   Each project can also have an issue tracker and a wiki.
 
-              - if current_application_settings.sign_in_text.present?
-                = markdown_field(current_application_settings, :sign_in_text)
+              - if Gitlab::CurrentSettings.sign_in_text.present?
+                = markdown_field(Gitlab::CurrentSettings.current_application_settings, :sign_in_text)
 
       %hr.footer-fixed
       .container.footer-container

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

@@ -28,7 +28,7 @@
             = link_to profile_account_path do
               %strong.fly-out-top-item-name
                 #{ _('Account') }
-      - if current_application_settings.user_oauth_applications?
+      - if Gitlab::CurrentSettings.user_oauth_applications?
         = nav_link(controller: 'oauth/applications') do
           = link_to applications_profile_path do
             .nav-icon-container

app/views/notify/_note_email.html.haml

@@ -22,7 +22,7 @@
         - else
           commented on a #{link_to 'discussion', @target_url}
 
-- elsif current_application_settings.email_author_in_body
+- elsif Gitlab::CurrentSettings.email_author_in_body
   %p.details
     #{link_to @note.author_name, user_url(@note.author)} commented:
 

app/views/notify/_note_email.text.erb

@@ -12,7 +12,7 @@
 <%=   ":" -%>
 
 
-<%  elsif current_application_settings.email_author_in_body -%>
+<%  elsif Gitlab::CurrentSettings.email_author_in_body -%>
 <%=     "#{@note.author_name} commented:" -%>
 
 

app/views/notify/new_issue_email.html.haml

-- if current_application_settings.email_author_in_body
+- if Gitlab::CurrentSettings.email_author_in_body
   %p.details
     #{link_to @issue.author_name, user_url(@issue.author)} created an issue:
 

app/views/notify/new_merge_request_email.html.haml

-- if current_application_settings.email_author_in_body
+- if Gitlab::CurrentSettings.email_author_in_body
   %p.details
     #{link_to @merge_request.author_name, user_url(@merge_request.author)} created a merge request:
 

app/views/notify/new_user_email.html.haml

 %p
   Hi #{@user['name']}!
 %p
-  - if current_application_settings.allow_signup?
+  - if Gitlab::CurrentSettings.allow_signup?
     Your account has been created successfully.
   - else
     The Administrator created an account for you. Now you are a member of the company GitLab application.

app/views/projects/_export.html.haml

-- return unless current_application_settings.project_export_enabled?
+- return unless Gitlab::CurrentSettings.project_export_enabled?
 
 - project = local_assigns.fetch(:project)
 - expanded = Rails.env.test?

app/views/projects/commits/_commit.html.haml

@@ -6,7 +6,7 @@
 - link = commit_path(project, commit, merge_request: merge_request)
 - cache_key = [project.full_path,
                commit.id,
-               current_application_settings,
+               Gitlab::CurrentSettings.current_application_settings,
                @path.presence,
                current_controller?(:commits),
                merge_request&.iid,

app/views/projects/pipelines_settings/_show.html.haml

@@ -31,7 +31,7 @@
             .radio
               = form.label :enabled_ do
                 = form.radio_button :enabled, ''
-                %strong Instance default (#{current_application_settings.auto_devops_enabled? ? 'enabled' : 'disabled'})
+                %strong Instance default (#{Gitlab::CurrentSettings.auto_devops_enabled? ? 'enabled' : 'disabled'})
                 %br
                 %span.descr
                   Follow the instance default to either have Auto DevOps enabled or disabled when there is no project specific <code>.gitlab-ci.yml</code>.

app/views/projects/runners/_shared_runners.html.haml

 %h3 Shared Runners
 
 .bs-callout.bs-callout-warning.shared-runners-description
-  - if current_application_settings.shared_runners_text.present?
-    = markdown_field(current_application_settings, :shared_runners_text)
+  - if Gitlab::CurrentSettings.shared_runners_text.present?
+    = markdown_field(Gitlab::CurrentSettings.current_application_settings, :shared_runners_text)
   - else
     GitLab Shared Runners execute code of different projects on the same Runner
     unless you configure GitLab Runner Autoscale with MaxBuilds 1 (which it is

app/workers/git_garbage_collect_worker.rb

 class GitGarbageCollectWorker
   include ApplicationWorker
-  include Gitlab::CurrentSettings
 
   sidekiq_options retry: false
 
@@ -102,7 +101,7 @@ class GitGarbageCollectWorker
   end
 
   def bitmaps_enabled?
-    current_application_settings.housekeeping_bitmaps_enabled
+    Gitlab::CurrentSettings.housekeeping_bitmaps_enabled
   end
 
   def git(write_bitmaps:)

lib/api/helpers/runner.rb

 module API
   module Helpers
     module Runner
-      include Gitlab::CurrentSettings
-
       JOB_TOKEN_HEADER = 'HTTP_JOB_TOKEN'.freeze
       JOB_TOKEN_PARAM = :token
       UPDATE_RUNNER_EVERY = 10 * 60
 
       def runner_registration_token_valid?
         ActiveSupport::SecurityUtils.variable_size_secure_compare(params[:token],
-                                                                  current_application_settings.runners_registration_token)
+                                                                  Gitlab::CurrentSettings.runners_registration_token)
       end
 
       def get_runner_version_from_params
@@ -70,7 +68,7 @@ module API
       end
 
       def max_artifacts_size
-        current_application_settings.max_artifacts_size.megabytes.to_i
+        Gitlab::CurrentSettings.max_artifacts_size.megabytes.to_i
       end
     end
   end

lib/email_template_interceptor.rb

 # Read about interceptors in http://guides.rubyonrails.org/action_mailer_basics.html#intercepting-emails
 class EmailTemplateInterceptor
-  extend Gitlab::CurrentSettings
-
   def self.delivering_email(message)
     # Remove HTML part if HTML emails are disabled.
-    unless current_application_settings.html_emails_enabled
+    unless Gitlab::CurrentSettings.html_emails_enabled
       message.parts.delete_if do |part|
         part.content_type.start_with?('text/html')
       end

lib/gitlab/asciidoc.rb

@@ -6,8 +6,6 @@ module Gitlab
   # Parser/renderer for the AsciiDoc format that uses Asciidoctor and filters
   # the resulting HTML through HTML pipeline filters.
   module Asciidoc
-    extend Gitlab::CurrentSettings
-
     DEFAULT_ADOC_ATTRS = [
       'showtitle', 'idprefix=user-content-', 'idseparator=-', 'env=gitlab',
       'env-gitlab', 'source-highlighter=html-pipeline', 'icons=font'
@@ -33,9 +31,9 @@ module Gitlab
 
     def self.plantuml_setup
       Asciidoctor::PlantUml.configure do |conf|
-        conf.url = current_application_settings.plantuml_url
-        conf.svg_enable = current_application_settings.plantuml_enabled
-        conf.png_enable = current_application_settings.plantuml_enabled
+        conf.url = Gitlab::CurrentSettings.plantuml_url
+        conf.svg_enable = Gitlab::CurrentSettings.plantuml_enabled
+        conf.png_enable = Gitlab::CurrentSettings.plantuml_enabled
         conf.txt_enable = false
       end
     end

lib/gitlab/auth.rb

@@ -14,8 +14,6 @@ module Gitlab
     DEFAULT_SCOPES = [:api].freeze
 
     class << self
-      include Gitlab::CurrentSettings
-
       def find_for_git_client(login, password, project:, ip:)
         raise "Must provide an IP for rate limiting" if ip.nil?
 
@@ -57,7 +55,7 @@ module Gitlab
           if user.nil? || user.ldap_user?
             # Second chance - try LDAP authentication
             Gitlab::LDAP::Authentication.login(login, password)
-          elsif current_application_settings.password_authentication_enabled_for_git?
+          elsif Gitlab::CurrentSettings.password_authentication_enabled_for_git?
             user if user.active? && user.valid_password?(password)
           end
         end
@@ -87,7 +85,7 @@ module Gitlab
       private
 
       def authenticate_using_internal_or_ldap_password?
-        current_application_settings.password_authentication_enabled_for_git? || Gitlab::LDAP::Config.enabled?
+        Gitlab::CurrentSettings.password_authentication_enabled_for_git? || Gitlab::LDAP::Config.enabled?
       end
 
       def service_request_check(login, password, project)

lib/gitlab/current_settings.rb

 module Gitlab
   module CurrentSettings
-    extend self
-
+    class << self
       def current_application_settings
         if RequestStore.active?
           RequestStore.fetch(:current_application_settings) { ensure_application_settings! }
@@ -10,10 +9,16 @@ module Gitlab
         end
       end
 
-    delegate :sidekiq_throttling_enabled?, to: :current_application_settings
-
       def fake_application_settings(defaults = ::ApplicationSetting.defaults)
-      FakeApplicationSettings.new(defaults)
+        Gitlab::FakeApplicationSettings.new(defaults)
+      end
+
+      def method_missing(name, *args, &block)
+        current_application_settings.send(name, *args, &block) # rubocop:disable GitlabSecurity/PublicSend
+      end
+
+      def respond_to_missing?(name, include_private = false)
+        current_application_settings.respond_to?(name, include_private) || super
       end
 
       private
@@ -70,4 +75,5 @@ module Gitlab
         false
       end
     end
+  end
 end

lib/gitlab/gon_helper.rb

@@ -3,12 +3,11 @@
 module Gitlab
   module GonHelper
     include WebpackHelper
-    include Gitlab::CurrentSettings
 
     def add_gon_variables
       gon.api_version            = 'v4'
       gon.default_avatar_url     = URI.join(Gitlab.config.gitlab.url, ActionController::Base.helpers.image_path('no_avatar.png')).to_s
-      gon.max_file_size          = current_application_settings.max_attachment_size
+      gon.max_file_size          = Gitlab::CurrentSettings.max_attachment_size
       gon.asset_host             = ActionController::Base.asset_host
       gon.webpack_public_path    = webpack_public_path
       gon.relative_url_root      = Gitlab.config.gitlab.relative_url_root
@@ -16,7 +15,7 @@ module Gitlab
       gon.user_color_scheme      = Gitlab::ColorSchemes.for_user(current_user).css_class
       gon.katex_css_url          = ActionController::Base.helpers.asset_path('katex.css')
       gon.katex_js_url           = ActionController::Base.helpers.asset_path('katex.js')
-      gon.sentry_dsn             = current_application_settings.clientside_sentry_dsn if current_application_settings.clientside_sentry_enabled
+      gon.sentry_dsn             = Gitlab::CurrentSettings.clientside_sentry_dsn if Gitlab::CurrentSettings.clientside_sentry_enabled
       gon.gitlab_url             = Gitlab.config.gitlab.url
       gon.revision               = Gitlab::REVISION
       gon.gitlab_logo            = ActionController::Base.helpers.asset_path('gitlab_logo.png')

lib/gitlab/legacy_github_import/project_creator.rb

 module Gitlab
   module LegacyGithubImport
     class ProjectCreator
-      include Gitlab::CurrentSettings
-
       attr_reader :repo, :name, :namespace, :current_user, :session_data, :type
 
       def initialize(repo, name, namespace, current_user, session_data, type: 'github')
@@ -36,7 +34,7 @@ module Gitlab
       end
 
       def visibility_level
-        repo.private ? Gitlab::VisibilityLevel::PRIVATE : current_application_settings.default_project_visibility
+        repo.private ? Gitlab::VisibilityLevel::PRIVATE : Gitlab::CurrentSettings.default_project_visibility
       end
 
       #

lib/gitlab/metrics/prometheus.rb

@@ -71,8 +71,7 @@ module Gitlab
         end
 
         def prometheus_metrics_enabled_unmemoized
-          metrics_folder_present? &&
-            Gitlab::CurrentSettings.current_application_settings[:prometheus_metrics_enabled] || false
+          metrics_folder_present? && Gitlab::CurrentSettings.prometheus_metrics_enabled || false
         end
       end
     end

lib/gitlab/middleware/go.rb

@@ -4,7 +4,6 @@ module Gitlab
   module Middleware
     class Go
       include ActionView::Helpers::TagHelper
-      include Gitlab::CurrentSettings
 
       PROJECT_PATH_REGEX = %r{\A(#{Gitlab::PathRegex.full_namespace_route_regex}/#{Gitlab::PathRegex.project_route_regex})/}.freeze
 
@@ -42,7 +41,7 @@ module Gitlab
         project_url = URI.join(config.gitlab.url, path)
         import_prefix = strip_url(project_url.to_s)
 
-        repository_url = if current_application_settings.enabled_git_access_protocol == 'ssh'
+        repository_url = if Gitlab::CurrentSettings.enabled_git_access_protocol == 'ssh'
                            shell = config.gitlab_shell
                            port = ":#{shell.ssh_port}" unless shell.ssh_port == 22
                            "ssh://#{shell.ssh_user}@#{shell.ssh_host}#{port}/#{path}.git"

lib/gitlab/performance_bar.rb

 module Gitlab
   module PerformanceBar
-    extend Gitlab::CurrentSettings
-
     ALLOWED_USER_IDS_KEY = 'performance_bar_allowed_user_ids:v2'.freeze
     EXPIRY_TIME = 5.minutes
 
@@ -13,7 +11,7 @@ module Gitlab
     end
 
     def self.allowed_group_id
-      current_application_settings.performance_bar_allowed_group_id
+      Gitlab::CurrentSettings.performance_bar_allowed_group_id
     end
 
     def self.allowed_user_ids

lib/gitlab/polling_interval.rb

 module Gitlab
   class PollingInterval
-    extend Gitlab::CurrentSettings
-
     HEADER_NAME = 'Poll-Interval'.freeze
 
     def self.set_header(response, interval:)
       if polling_enabled?
-        multiplier = current_application_settings.polling_interval_multiplier
+        multiplier = Gitlab::CurrentSettings.polling_interval_multiplier
         value = (interval * multiplier).to_i
       else
         value = -1
@@ -16,7 +14,7 @@ module Gitlab
     end
 
     def self.polling_enabled?
-      !current_application_settings.polling_interval_multiplier.zero?
+      !Gitlab::CurrentSettings.polling_interval_multiplier.zero?
     end
   end
 end

lib/gitlab/protocol_access.rb

 module Gitlab
   module ProtocolAccess
-    extend Gitlab::CurrentSettings
-
     def self.allowed?(protocol)
       if protocol == 'web'
         true
-      elsif current_application_settings.enabled_git_access_protocol.blank?
+      elsif Gitlab::CurrentSettings.enabled_git_access_protocol.blank?
         true
       else
-        protocol == current_application_settings.enabled_git_access_protocol
+        protocol == Gitlab::CurrentSettings.enabled_git_access_protocol
       end
     end
   end

lib/gitlab/recaptcha.rb

 module Gitlab
   module Recaptcha
-    extend Gitlab::CurrentSettings
-
     def self.load_configurations!
-      if current_application_settings.recaptcha_enabled
+      if Gitlab::CurrentSettings.recaptcha_enabled
         ::Recaptcha.configure do |config|
-          config.public_key  = current_application_settings.recaptcha_site_key
-          config.private_key = current_application_settings.recaptcha_private_key
+          config.public_key  = Gitlab::CurrentSettings.recaptcha_site_key
+          config.private_key = Gitlab::CurrentSettings.recaptcha_private_key
         end
 
         true
@@ -14,7 +12,7 @@ module Gitlab
     end
 
     def self.enabled?
-      current_application_settings.recaptcha_enabled
+      Gitlab::CurrentSettings.recaptcha_enabled
     end
   end
 end

lib/gitlab/sentry.rb

 module Gitlab
   module Sentry
-    extend Gitlab::CurrentSettings
-
     def self.enabled?
-      Rails.env.production? && current_application_settings.sentry_enabled?
+      Rails.env.production? && Gitlab::CurrentSettings.sentry_enabled?
     end
 
     def self.context(current_user = nil)

lib/gitlab/usage_data.rb

 module Gitlab
   class UsageData
     class << self
-      include Gitlab::CurrentSettings
-
       def data(force_refresh: false)
         Rails.cache.fetch('usage_data', force: force_refresh, expires_in: 2.weeks) { uncached_data }
       end
@@ -19,7 +17,7 @@ module Gitlab
 
       def license_usage_data
         usage_data = {
-          uuid: current_application_settings.uuid,
+          uuid: Gitlab::CurrentSettings.uuid,
           hostname: Gitlab.config.gitlab.host,
           version: Gitlab::VERSION,
           active_user_count: User.active.count,
@@ -79,9 +77,9 @@ module Gitlab
 
       def features_usage_data_ce
         {
-          signup: current_application_settings.allow_signup?,
+          signup: Gitlab::CurrentSettings.allow_signup?,
           ldap: Gitlab.config.ldap.enabled,
-          gravatar: current_application_settings.gravatar_enabled?,
+          gravatar: Gitlab::CurrentSettings.gravatar_enabled?,
           omniauth: Gitlab.config.omniauth.enabled,
           reply_by_email: Gitlab::IncomingEmail.enabled?,
           container_registry: Gitlab.config.registry.enabled,

lib/gitlab/visibility_level.rb

@@ -5,7 +5,6 @@
 #
 module Gitlab
   module VisibilityLevel
-    extend CurrentSettings
     extend ActiveSupport::Concern
 
     included do
@@ -58,7 +57,7 @@ module Gitlab
       end
 
       def allowed_levels
-        restricted_levels = current_application_settings.restricted_visibility_levels
+        restricted_levels = Gitlab::CurrentSettings.restricted_visibility_levels
 
         self.values - restricted_levels
       end
@@ -81,7 +80,7 @@ module Gitlab
       end
 
       def non_restricted_level?(level)
-        restricted_levels = current_application_settings.restricted_visibility_levels
+        restricted_levels = Gitlab::CurrentSettings.restricted_visibility_levels
 
         if restricted_levels.nil?
           true

spec/controllers/health_check_controller_spec.rb

@@ -5,7 +5,7 @@ describe HealthCheckController do
 
   let(:json_response) { JSON.parse(response.body) }
   let(:xml_response) { Hash.from_xml(response.body)['hash'] }
-  let(:token) { current_application_settings.health_check_access_token }
+  let(:token) { Gitlab::CurrentSettings.health_check_access_token }
   let(:whitelisted_ip) { '127.0.0.1' }
   let(:not_whitelisted_ip) { '127.0.0.2' }
 

spec/controllers/health_controller_spec.rb

@@ -4,7 +4,7 @@ describe HealthController do
   include StubENV
 
   let(:json_response) { JSON.parse(response.body) }
-  let(:token) { current_application_settings.health_check_access_token }
+  let(:token) { Gitlab::CurrentSettings.health_check_access_token }
   let(:whitelisted_ip) { '127.0.0.1' }
   let(:not_whitelisted_ip) { '127.0.0.2' }
 

spec/controllers/oauth/applications_controller_spec.rb

@@ -16,8 +16,7 @@ describe Oauth::ApplicationsController do
       end
 
       it 'redirects back to profile page if OAuth applications are disabled' do
-        settings = double(user_oauth_applications?: false)
-        allow_any_instance_of(Gitlab::CurrentSettings).to receive(:current_application_settings).and_return(settings)
+        allow(Gitlab::CurrentSettings.current_application_settings).to receive(:user_oauth_applications?).and_return(false)
 
         get :index
 

spec/features/admin/admin_health_check_spec.rb

@@ -17,7 +17,7 @@ feature "Admin Health Check", :feature do
       page.has_text? 'Health Check'
       page.has_text? 'Health information can be retrieved'
 
-      token = current_application_settings.health_check_access_token
+      token = Gitlab::CurrentSettings.health_check_access_token
 
       expect(page).to have_content("Access token is #{token}")
       expect(page).to have_selector('#health-check-token', text: token)
@@ -25,7 +25,7 @@ feature "Admin Health Check", :feature do
 
     describe 'reload access token' do
       it 'changes the access token' do
-        orig_token = current_application_settings.health_check_access_token
+        orig_token = Gitlab::CurrentSettings.health_check_access_token
         click_button 'Reset health check access token'
 
         expect(page).to have_content('New health check access token has been generated!')

spec/features/admin/admin_runners_spec.rb

@@ -156,7 +156,7 @@ describe "Admin Runners" do
   end
 
   describe 'runners registration token' do
-    let!(:token) { current_application_settings.runners_registration_token }
+    let!(:token) { Gitlab::CurrentSettings.runners_registration_token }
 
     before do
       visit admin_runners_path

spec/features/admin/admin_settings_spec.rb

@@ -38,12 +38,12 @@ feature 'Admin updates settings' do
     uncheck 'Project export enabled'
     click_button 'Save'
 
-    expect(current_application_settings.gravatar_enabled).to be_falsey
-    expect(current_application_settings.home_page_url).to eq "https://about.gitlab.com/"
-    expect(current_application_settings.help_page_text).to eq "Example text"
-    expect(current_application_settings.help_page_hide_commercial_content).to be_truthy
-    expect(current_application_settings.help_page_support_url).to eq "http://example.com/help"
-    expect(current_application_settings.project_export_enabled).to be_falsey
+    expect(Gitlab::CurrentSettings.gravatar_enabled).to be_falsey
+    expect(Gitlab::CurrentSettings.home_page_url).to eq "https://about.gitlab.com/"
+    expect(Gitlab::CurrentSettings.help_page_text).to eq "Example text"
+    expect(Gitlab::CurrentSettings.help_page_hide_commercial_content).to be_truthy
+    expect(Gitlab::CurrentSettings.help_page_support_url).to eq "http://example.com/help"
+    expect(Gitlab::CurrentSettings.project_export_enabled).to be_falsey
     expect(page).to have_content "Application settings saved successfully"
   end
 

spec/features/issues/spam_issues_spec.rb

@@ -9,7 +9,7 @@ describe 'New issue', :js do
   before do
     stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
 
-    current_application_settings.update!(
+    Gitlab::CurrentSettings.update!(
       akismet_enabled: true,
       akismet_api_key: 'testkey',
       recaptcha_enabled: true,

spec/helpers/version_check_helper_spec.rb

@@ -4,7 +4,7 @@ describe VersionCheckHelper do
   describe '#version_status_badge' do
     it 'should return nil if not dev environment and not enabled' do
       allow(Rails.env).to receive(:production?) { false }
-      allow(helper.current_application_settings).to receive(:version_check_enabled) { false }
+      allow(Gitlab::CurrentSettings.current_application_settings).to receive(:version_check_enabled) { false }
 
       expect(helper.version_status_badge).to be(nil)
     end
@@ -12,7 +12,7 @@ describe VersionCheckHelper do
     context 'when production and enabled' do
       before do
         allow(Rails.env).to receive(:production?) { true }
-        allow(helper.current_application_settings).to receive(:version_check_enabled) { true }
+        allow(Gitlab::CurrentSettings.current_application_settings).to receive(:version_check_enabled) { true }
         allow_any_instance_of(VersionCheck).to receive(:url) { 'https://version.host.com/check.svg?gitlab_info=xxx' }
 
         @image_tag = helper.version_status_badge

spec/lib/gitlab/current_settings_spec.rb

@@ -8,22 +8,37 @@ describe Gitlab::CurrentSettings do
   end
 
   describe '#current_application_settings' do
+    it 'allows keys to be called directly' do
+      db_settings = create(:application_setting,
+                           home_page_url: 'http://mydomain.com',
+                           signup_enabled: false)
+
+      expect(described_class.home_page_url).to eq(db_settings.home_page_url)
+      expect(described_class.signup_enabled?).to be_falsey
+      expect(described_class.signup_enabled).to be_falsey
+      expect(described_class.metrics_sample_interval).to be(15)
+    end
+
     context 'with DB available' do
       before do
-        allow_any_instance_of(described_class).to receive(:connect_to_db?).and_return(true)
+        # For some reason, `allow(described_class).to receive(:connect_to_db?).and_return(true)` causes issues
+        # during the initialization phase of the test suite, so instead let's mock the internals of it
+        allow(ActiveRecord::Base.connection).to receive(:active?).and_return(true)
+        allow(ActiveRecord::Base.connection).to receive(:table_exists?).and_call_original
+        allow(ActiveRecord::Base.connection).to receive(:table_exists?).with('application_settings').and_return(true)
       end
 
       it 'attempts to use cached values first' do
         expect(ApplicationSetting).to receive(:cached)
 
-        expect(current_application_settings).to be_a(ApplicationSetting)
+        expect(described_class.current_application_settings).to be_a(ApplicationSetting)
       end
 
       it 'falls back to DB if Redis returns an empty value' do
         expect(ApplicationSetting).to receive(:cached).and_return(nil)
         expect(ApplicationSetting).to receive(:last).and_call_original.twice
 
-        expect(current_application_settings).to be_a(ApplicationSetting)
+        expect(described_class.current_application_settings).to be_a(ApplicationSetting)
       end
 
       it 'falls back to DB if Redis fails' do
@@ -32,14 +47,14 @@ describe Gitlab::CurrentSettings do
         expect(ApplicationSetting).to receive(:cached).and_raise(::Redis::BaseError)
         expect(Rails.cache).to receive(:fetch).with(ApplicationSetting::CACHE_KEY).and_raise(Redis::BaseError)
 
-        expect(current_application_settings).to eq(db_settings)
+        expect(described_class.current_application_settings).to eq(db_settings)
       end
 
       it 'creates default ApplicationSettings if none are present' do
         expect(ApplicationSetting).to receive(:cached).and_raise(::Redis::BaseError)
         expect(Rails.cache).to receive(:fetch).with(ApplicationSetting::CACHE_KEY).and_raise(Redis::BaseError)
 
-        settings = current_application_settings
+        settings = described_class.current_application_settings
 
         expect(settings).to be_a(ApplicationSetting)
         expect(settings).to be_persisted
@@ -52,7 +67,7 @@ describe Gitlab::CurrentSettings do
         end
 
         it 'returns an in-memory ApplicationSetting object' do
-          settings = current_application_settings
+          settings = described_class.current_application_settings
 
           expect(settings).to be_a(OpenStruct)
           expect(settings.sign_in_enabled?).to eq(settings.sign_in_enabled)
@@ -63,7 +78,7 @@ describe Gitlab::CurrentSettings do
           db_settings = create(:application_setting,
                                home_page_url: 'http://mydomain.com',
                                signup_enabled: false)
-          settings = current_application_settings
+          settings = described_class.current_application_settings
           app_defaults = ApplicationSetting.last
 
           expect(settings).to be_a(OpenStruct)
@@ -80,15 +95,16 @@ describe Gitlab::CurrentSettings do
 
     context 'with DB unavailable' do
       before do
-        allow_any_instance_of(described_class).to receive(:connect_to_db?).and_return(false)
-        allow_any_instance_of(described_class).to receive(:retrieve_settings_from_database_cache?).and_return(nil)
+        # For some reason, `allow(described_class).to receive(:connect_to_db?).and_return(false)` causes issues
+        # during the initialization phase of the test suite, so instead let's mock the internals of it
+        allow(ActiveRecord::Base.connection).to receive(:active?).and_return(false)
       end
 
       it 'returns an in-memory ApplicationSetting object' do
         expect(ApplicationSetting).not_to receive(:current)
         expect(ApplicationSetting).not_to receive(:last)
 
-        expect(current_application_settings).to be_a(OpenStruct)
+        expect(described_class.current_application_settings).to be_a(OpenStruct)
       end
     end
 
@@ -101,8 +117,8 @@ describe Gitlab::CurrentSettings do
         expect(ApplicationSetting).not_to receive(:current)
         expect(ApplicationSetting).not_to receive(:last)
 
-        expect(current_application_settings).to be_a(ApplicationSetting)
-        expect(current_application_settings).not_to be_persisted
+        expect(described_class.current_application_settings).to be_a(ApplicationSetting)
+        expect(described_class.current_application_settings).not_to be_persisted
       end
     end
   end

spec/lib/gitlab/metrics_spec.rb

@@ -20,7 +20,7 @@ describe Gitlab::Metrics do
 
     context 'prometheus metrics enabled in config' do
       before do
-        allow(Gitlab::CurrentSettings).to receive(:current_application_settings).and_return(prometheus_metrics_enabled: true)
+        allow(Gitlab::CurrentSettings).to receive(:prometheus_metrics_enabled).and_return(true)
       end
 
       context 'when metrics folder is present' do

spec/lib/gitlab/usage_data_spec.rb

@@ -103,9 +103,9 @@ describe Gitlab::UsageData do
     subject { described_class.features_usage_data_ce }
 
     it 'gathers feature usage data' do
-      expect(subject[:signup]).to eq(current_application_settings.allow_signup?)
+      expect(subject[:signup]).to eq(Gitlab::CurrentSettings.allow_signup?)
       expect(subject[:ldap]).to eq(Gitlab.config.ldap.enabled)
-      expect(subject[:gravatar]).to eq(current_application_settings.gravatar_enabled?)
+      expect(subject[:gravatar]).to eq(Gitlab::CurrentSettings.gravatar_enabled?)
       expect(subject[:omniauth]).to eq(Gitlab.config.omniauth.enabled)
       expect(subject[:reply_by_email]).to eq(Gitlab::IncomingEmail.enabled?)
       expect(subject[:container_registry]).to eq(Gitlab.config.registry.enabled)
@@ -129,7 +129,7 @@ describe Gitlab::UsageData do
     subject { described_class.license_usage_data }
 
     it "gathers license data" do
-      expect(subject[:uuid]).to eq(current_application_settings.uuid)
+      expect(subject[:uuid]).to eq(Gitlab::CurrentSettings.uuid)
       expect(subject[:version]).to eq(Gitlab::VERSION)
       expect(subject[:active_user_count]).to eq(User.active.count)
       expect(subject[:recorded_at]).to be_a(Time)

spec/models/key_spec.rb

 require 'spec_helper'
 
 describe Key, :mailer do
-  include Gitlab::CurrentSettings
-
-  describe 'modules' do
-    subject { described_class }
-    it { is_expected.to include_module(Gitlab::CurrentSettings) }
-  end
-
   describe "Associations" do
     it { is_expected.to belong_to(:user) }
   end

spec/models/note_spec.rb

@@ -17,8 +17,6 @@ describe Note do
     it { is_expected.to include_module(Participable) }
     it { is_expected.to include_module(Mentionable) }
     it { is_expected.to include_module(Awardable) }
-
-    it { is_expected.to include_module(Gitlab::CurrentSettings) }
   end
 
   describe 'validation' do

spec/models/project_spec.rb

@@ -117,7 +117,6 @@ describe Project do
     it { is_expected.to include_module(Gitlab::ConfigHelper) }
     it { is_expected.to include_module(Gitlab::ShellAdapter) }
     it { is_expected.to include_module(Gitlab::VisibilityLevel) }
-    it { is_expected.to include_module(Gitlab::CurrentSettings) }
     it { is_expected.to include_module(Referable) }
     it { is_expected.to include_module(Sortable) }
   end

spec/models/user_spec.rb

 require 'spec_helper'
 
 describe User do
-  include Gitlab::CurrentSettings
   include ProjectForksHelper
 
   describe 'modules' do
     subject { described_class }
 
     it { is_expected.to include_module(Gitlab::ConfigHelper) }
-    it { is_expected.to include_module(Gitlab::CurrentSettings) }
     it { is_expected.to include_module(Referable) }
     it { is_expected.to include_module(Sortable) }
     it { is_expected.to include_module(TokenAuthenticatable) }
@@ -560,7 +558,7 @@ describe User do
         stub_config_setting(default_can_create_group: true)
 
         expect { user.update_attributes(external: false) }.to change { user.can_create_group }.to(true)
-          .and change { user.projects_limit }.to(current_application_settings.default_projects_limit)
+          .and change { user.projects_limit }.to(Gitlab::CurrentSettings.default_projects_limit)
       end
     end
 
@@ -826,7 +824,7 @@ describe User do
       end
     end
 
-    context 'when current_application_settings.user_default_external is true' do
+    context 'when Gitlab::CurrentSettings.user_default_external is true' do
       before do
         stub_application_setting(user_default_external: true)
       end

spec/requests/api/projects_spec.rb

@@ -2,8 +2,6 @@
 require 'spec_helper'
 
 describe API::Projects do
-  include Gitlab::CurrentSettings
-
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
   let(:user3) { create(:user) }

spec/requests/api/v3/projects_spec.rb

 require 'spec_helper'
 
 describe API::V3::Projects do
-  include Gitlab::CurrentSettings
-
   let(:user) { create(:user) }
   let(:user2) { create(:user) }
   let(:user3) { create(:user) }

spec/support/stored_repositories.rb

@@ -15,9 +15,7 @@ RSpec.configure do |config|
     # Track the maximum number of failures
     first_failure = Time.parse("2017-11-14 17:52:30")
     last_failure = Time.parse("2017-11-14 18:54:37")
-    failure_count = Gitlab::CurrentSettings
-                      .current_application_settings
-                      .circuitbreaker_failure_count_threshold + 1
+    failure_count = Gitlab::CurrentSettings.circuitbreaker_failure_count_threshold + 1
     cache_key = "#{Gitlab::Git::Storage::REDIS_KEY_PREFIX}broken:#{Gitlab::Environment.hostname}"
 
     Gitlab::Git::Storage.redis.with do |redis|

spec/support/stub_env.rb

 # Inspired by https://github.com/ljkbennett/stub_env/blob/master/lib/stub_env/helpers.rb
 module StubENV
-  include Gitlab::CurrentSettings
-
   def stub_env(key_or_hash, value = nil)
     init_stub unless env_stubbed?
 

spec/support/unique_ip_check_shared_examples.rb

@@ -9,7 +9,7 @@ shared_context 'unique ips sign in limit' do
   before do
     stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
 
-    current_application_settings.update!(
+    Gitlab::CurrentSettings.update!(
       unique_ips_limit_enabled: true,
       unique_ips_limit_time_window: 10000
     )
@@ -34,7 +34,7 @@ end
 shared_examples 'user login operation with unique ip limit' do
   include_context 'unique ips sign in limit' do
     before do
-      current_application_settings.update!(unique_ips_limit_per_user: 1)
+      Gitlab::CurrentSettings.update!(unique_ips_limit_per_user: 1)
     end
 
     it 'allows user authenticating from the same ip' do
@@ -52,7 +52,7 @@ end
 shared_examples 'user login request with unique ip limit' do |success_status = 200|
   include_context 'unique ips sign in limit' do
     before do
-      current_application_settings.update!(unique_ips_limit_per_user: 1)
+      Gitlab::CurrentSettings.update!(unique_ips_limit_per_user: 1)
     end
 
     it 'allows user authenticating from the same ip' do