Add latest changes from gitlab-org/gitlab@12-5-stable-ee

64 files changed, 554 insertions, 171 deletions

diff --git a/app/controllers/admin/abuse_reports_controller.rb b/app/controllers/admin/abuse_reports_controller.rb
index d5537023b26..31d825c235b 100644
--- a/app/controllers/admin/abuse_reports_controller.rb
+++ b/app/controllers/admin/abuse_reports_controller.rb
@@ -1,12 +1,9 @@
 # frozen_string_literal: true
 
 class Admin::AbuseReportsController < Admin::ApplicationController
-  # rubocop: disable CodeReuse/ActiveRecord
   def index
-    @abuse_reports = AbuseReport.order(id: :desc).page(params[:page])
-    @abuse_reports.includes(:reporter, :user)
+    @abuse_reports = AbuseReportsFinder.new(params).execute
   end
-  # rubocop: enable CodeReuse/ActiveRecord
 
   def destroy
     abuse_report = AbuseReport.find(params[:id])
diff --git a/app/controllers/admin/applications_controller.rb b/app/controllers/admin/applications_controller.rb
index 22e629ccf59..907b295870d 100644
--- a/app/controllers/admin/applications_controller.rb
+++ b/app/controllers/admin/applications_controller.rb
@@ -44,7 +44,7 @@ class Admin::ApplicationsController < Admin::ApplicationController
 
   def destroy
     @application.destroy
-    redirect_to admin_applications_url, status: 302, notice: _('Application was successfully destroyed.')
+    redirect_to admin_applications_url, status: :found, notice: _('Application was successfully destroyed.')
   end
 
   private
diff --git a/app/controllers/admin/groups_controller.rb b/app/controllers/admin/groups_controller.rb
index 85a37fcd43e..5455cefdc8e 100644
--- a/app/controllers/admin/groups_controller.rb
+++ b/app/controllers/admin/groups_controller.rb
@@ -69,7 +69,7 @@ class Admin::GroupsController < Admin::ApplicationController
     Groups::DestroyService.new(@group, current_user).async_execute
 
     redirect_to admin_groups_path,
-                status: 302,
+                status: :found,
                 alert: _('Group %{group_name} was scheduled for deletion.') % { group_name: @group.name }
   end
 
diff --git a/app/controllers/admin/identities_controller.rb b/app/controllers/admin/identities_controller.rb
index f518f7a657f..8f2e34a6294 100644
--- a/app/controllers/admin/identities_controller.rb
+++ b/app/controllers/admin/identities_controller.rb
@@ -38,9 +38,9 @@ class Admin::IdentitiesController < Admin::ApplicationController
   def destroy
     if @identity.destroy
       RepairLdapBlockedUserService.new(@user).execute
-      redirect_to admin_user_identities_path(@user), status: 302, notice: _('User identity was successfully removed.')
+      redirect_to admin_user_identities_path(@user), status: :found, notice: _('User identity was successfully removed.')
     else
-      redirect_to admin_user_identities_path(@user), status: 302, alert: _('Failed to remove user identity.')
+      redirect_to admin_user_identities_path(@user), status: :found, alert: _('Failed to remove user identity.')
     end
   end
 
diff --git a/app/controllers/admin/keys_controller.rb b/app/controllers/admin/keys_controller.rb
index 340eecd7632..58ea19d1210 100644
--- a/app/controllers/admin/keys_controller.rb
+++ b/app/controllers/admin/keys_controller.rb
@@ -17,9 +17,9 @@ class Admin::KeysController < Admin::ApplicationController
 
     respond_to do |format|
       if key.destroy
-        format.html { redirect_to keys_admin_user_path(user), status: 302, notice: _('User key was successfully removed.') }
+        format.html { redirect_to keys_admin_user_path(user), status: :found, notice: _('User key was successfully removed.') }
       else
-        format.html { redirect_to keys_admin_user_path(user), status: 302, alert: _('Failed to remove user key.') }
+        format.html { redirect_to keys_admin_user_path(user), status: :found, alert: _('Failed to remove user key.') }
       end
     end
   end
diff --git a/app/controllers/admin/labels_controller.rb b/app/controllers/admin/labels_controller.rb
index 90c1694fd2e..6cb206c1686 100644
--- a/app/controllers/admin/labels_controller.rb
+++ b/app/controllers/admin/labels_controller.rb
@@ -43,7 +43,7 @@ class Admin::LabelsController < Admin::ApplicationController
 
     respond_to do |format|
       format.html do
-        redirect_to admin_labels_path, status: 302, notice: _('Label was removed')
+        redirect_to admin_labels_path, status: :found, notice: _('Label was removed')
       end
       format.js
     end
diff --git a/app/controllers/admin/projects_controller.rb b/app/controllers/admin/projects_controller.rb
index 0e8c69eb7d6..cdedc34e634 100644
--- a/app/controllers/admin/projects_controller.rb
+++ b/app/controllers/admin/projects_controller.rb
@@ -41,7 +41,7 @@ class Admin::ProjectsController < Admin::ApplicationController
 
     redirect_to admin_projects_path, status: :found
   rescue Projects::DestroyService::DestroyError => ex
-    redirect_to admin_projects_path, status: 302, alert: ex.message
+    redirect_to admin_projects_path, status: :found, alert: ex.message
   end
 
   # rubocop: disable CodeReuse/ActiveRecord
diff --git a/app/controllers/admin/spam_logs_controller.rb b/app/controllers/admin/spam_logs_controller.rb
index 45cf0d3207e..a41d8a22650 100644
--- a/app/controllers/admin/spam_logs_controller.rb
+++ b/app/controllers/admin/spam_logs_controller.rb
@@ -13,7 +13,7 @@ class Admin::SpamLogsController < Admin::ApplicationController
     if params[:remove_user]
       spam_log.remove_user(deleted_by: current_user)
       redirect_to admin_spam_logs_path,
-                  status: 302,
+                  status: :found,
                   notice: _('User %{username} was successfully removed.') % { username: spam_log.user.username }
     else
       spam_log.destroy
diff --git a/app/controllers/admin/users_controller.rb b/app/controllers/admin/users_controller.rb
index 4c1ac8f206a..9fbfc59f630 100644
--- a/app/controllers/admin/users_controller.rb
+++ b/app/controllers/admin/users_controller.rb
@@ -169,7 +169,7 @@ class Admin::UsersController < Admin::ApplicationController
     user.delete_async(deleted_by: current_user, params: params.permit(:hard_delete))
 
     respond_to do |format|
-      format.html { redirect_to admin_users_path, status: 302, notice: _("The user is being deleted.") }
+      format.html { redirect_to admin_users_path, status: :found, notice: _("The user is being deleted.") }
       format.json { head :ok }
     end
   end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 27e88ae569e..25c1d80b117 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -12,6 +12,7 @@ class ApplicationController < ActionController::Base
   include EnforcesTwoFactorAuthentication
   include WithPerformanceBar
   include SessionlessAuthentication
+  include SessionsHelper
   include ConfirmEmailWarning
   include Gitlab::Tracking::ControllerConcern
   include Gitlab::Experimentation::ControllerConcern
@@ -29,13 +30,13 @@ class ApplicationController < ActionController::Base
   before_action :active_user_check, unless: :devise_controller?
   before_action :set_usage_stats_consent_flag
   before_action :check_impersonation_availability
-  before_action :require_role
+  before_action :required_signup_info
 
   around_action :set_locale
   around_action :set_session_storage
 
   after_action :set_page_title_header, if: :json_request?
-  after_action :limit_unauthenticated_session_times
+  after_action :limit_session_time, if: -> { !current_user }
 
   protect_from_forgery with: :exception, prepend: true
 
@@ -57,7 +58,7 @@ class ApplicationController < ActionController::Base
 
   rescue_from Encoding::CompatibilityError do |exception|
     log_exception(exception)
-    render "errors/encoding", layout: "errors", status: 500
+    render "errors/encoding", layout: "errors", status: :internal_server_error
   end
 
   rescue_from ActiveRecord::RecordNotFound do |exception|
@@ -103,24 +104,6 @@ class ApplicationController < ActionController::Base
     end
   end
 
-  # By default, all sessions are given the same expiration time configured in
-  # the session store (e.g. 1 week). However, unauthenticated users can
-  # generate a lot of sessions, primarily for CSRF verification. It makes
-  # sense to reduce the TTL for unauthenticated to something much lower than
-  # the default (e.g. 1 hour) to limit Redis memory. In addition, Rails
-  # creates a new session after login, so the short TTL doesn't even need to
-  # be extended.
-  def limit_unauthenticated_session_times
-    return if current_user
-
-    # Rack sets this header, but not all tests may have it: https://github.com/rack/rack/blob/fdcd03a3c5a1c51d1f96fc97f9dfa1a9deac0c77/lib/rack/session/abstract/id.rb#L251-L259
-    return unless request.env['rack.session.options']
-
-    # This works because Rack uses these options every time a request is handled:
-    # https://github.com/rack/rack/blob/fdcd03a3c5a1c51d1f96fc97f9dfa1a9deac0c77/lib/rack/session/abstract/id.rb#L342
-    request.env['rack.session.options'][:expire_after] = Settings.gitlab['unauthenticated_session_expire_delay']
-  end
-
   def render(*args)
     super.tap do
       # Set a header for custom error pages to prevent them from being intercepted by gitlab-workhorse
@@ -214,25 +197,29 @@ class ApplicationController < ActionController::Base
   end
 
   def git_not_found!
-    render "errors/git_not_found.html", layout: "errors", status: 404
+    render "errors/git_not_found.html", layout: "errors", status: :not_found
   end
 
   def render_403
     respond_to do |format|
       format.any { head :forbidden }
-      format.html { render "errors/access_denied", layout: "errors", status: 403 }
+      format.html { render "errors/access_denied", layout: "errors", status: :forbidden }
     end
   end
 
   def render_404
     respond_to do |format|
-      format.html { render "errors/not_found", layout: "errors", status: 404 }
+      format.html { render "errors/not_found", layout: "errors", status: :not_found }
       # Prevent the Rails CSRF protector from thinking a missing .js file is a JavaScript file
       format.js { render json: '', status: :not_found, content_type: 'application/json' }
       format.any { head :not_found }
     end
   end
 
+  def respond_201
+    head :created
+  end
+
   def respond_422
     head :unprocessable_entity
   end
@@ -551,10 +538,13 @@ class ApplicationController < ActionController::Base
     @current_user_mode ||= Gitlab::Auth::CurrentUserMode.new(current_user)
   end
 
-  # A user requires a role when they are part of the experimental signup flow (executed by the Growth team). Users
-  # are redirected to the welcome page when their role is required and the experiment is enabled for the current user.
-  def require_role
-    return unless current_user && current_user.role_required? && experiment_enabled?(:signup_flow)
+  # A user requires a role and have the setup_for_company attribute set when they are part of the experimental signup
+  # flow (executed by the Growth team). Users are redirected to the welcome page when their role is required and the
+  # experiment is enabled for the current user.
+  def required_signup_info
+    return unless current_user
+    return unless current_user.role_required?
+    return unless experiment_enabled?(:signup_flow)
 
     store_location_for :user, request.fullpath
 
diff --git a/app/controllers/boards/issues_controller.rb b/app/controllers/boards/issues_controller.rb
index 9894dd7d180..1298b33471b 100644
--- a/app/controllers/boards/issues_controller.rb
+++ b/app/controllers/boards/issues_controller.rb
@@ -13,7 +13,7 @@ module Boards
 
     requires_cross_project_access if: -> { board&.group_board? }
 
-    before_action :whitelist_query_limiting, only: [:index, :update, :bulk_move]
+    before_action :whitelist_query_limiting, only: [:bulk_move]
     before_action :authorize_read_issue, only: [:index]
     before_action :authorize_create_issue, only: [:create]
     before_action :authorize_update_issue, only: [:update]
@@ -130,8 +130,7 @@ module Boards
     end
 
     def whitelist_query_limiting
-      # Also see https://gitlab.com/gitlab-org/gitlab-foss/issues/42439
-      Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab-foss/issues/42428')
+      Gitlab::QueryLimiting.whitelist('https://gitlab.com/gitlab-org/gitlab/issues/35174')
     end
 
     def validate_id_list
diff --git a/app/controllers/clusters/applications_controller.rb b/app/controllers/clusters/applications_controller.rb
index 16c2365f85d..be68d0d0a1d 100644
--- a/app/controllers/clusters/applications_controller.rb
+++ b/app/controllers/clusters/applications_controller.rb
@@ -47,7 +47,7 @@ class Clusters::ApplicationsController < Clusters::BaseController
   end
 
   def cluster_application_params
-    params.permit(:application, :hostname, :email)
+    params.permit(:application, :hostname, :kibana_hostname, :email, :stack)
   end
 
   def cluster_application_destroy_params
diff --git a/app/controllers/clusters/clusters_controller.rb b/app/controllers/clusters/clusters_controller.rb
index 993aba661f3..9a539cf7c24 100644
--- a/app/controllers/clusters/clusters_controller.rb
+++ b/app/controllers/clusters/clusters_controller.rb
@@ -3,18 +3,22 @@
 class Clusters::ClustersController < Clusters::BaseController
   include RoutableActions
 
-  before_action :cluster, except: [:index, :new, :create_gcp, :create_user]
+  before_action :cluster, only: [:cluster_status, :show, :update, :destroy]
   before_action :generate_gcp_authorize_url, only: [:new]
   before_action :validate_gcp_token, only: [:new]
   before_action :gcp_cluster, only: [:new]
   before_action :user_cluster, only: [:new]
-  before_action :authorize_create_cluster!, only: [:new]
+  before_action :authorize_create_cluster!, only: [:new, :authorize_aws_role, :revoke_aws_role, :aws_proxy]
   before_action :authorize_update_cluster!, only: [:update]
   before_action :authorize_admin_cluster!, only: [:destroy]
   before_action :update_applications_status, only: [:cluster_status]
   before_action only: [:new, :create_gcp] do
     push_frontend_feature_flag(:create_eks_clusters)
   end
+  before_action only: [:show] do
+    push_frontend_feature_flag(:enable_cluster_application_elastic_stack)
+    push_frontend_feature_flag(:enable_cluster_application_crossplane)
+  end
 
   helper_method :token_in_session
 
@@ -40,10 +44,13 @@ class Clusters::ClustersController < Clusters::BaseController
   def new
     return unless Feature.enabled?(:create_eks_clusters)
 
-    @gke_selected = params[:provider] == 'gke'
-    @eks_selected = params[:provider] == 'eks'
+    if params[:provider] == 'aws'
+      @aws_role = current_user.aws_role || Aws::Role.new
+      @aws_role.ensure_role_external_id!
 
-    return redirect_to @authorize_url if @gke_selected && @authorize_url && !@valid_gcp_token
+    elsif params[:provider] == 'gcp'
+      redirect_to @authorize_url if @authorize_url && !@valid_gcp_token
+    end
   end
 
   # Overridding ActionController::Metal#status is NOT a good idea
@@ -86,13 +93,12 @@ class Clusters::ClustersController < Clusters::BaseController
   end
 
   def destroy
-    if cluster.destroy
-      flash[:notice] = _('Kubernetes cluster integration was successfully removed.')
-      redirect_to clusterable.index_path, status: :found
-    else
-      flash[:notice] = _('Kubernetes cluster integration was not removed.')
-      render :show
-    end
+    response = Clusters::DestroyService
+      .new(current_user, destroy_params)
+      .execute(cluster)
+
+    flash[:notice] = response[:message]
+    redirect_to clusterable.index_path, status: :found
   end
 
   def create_gcp
@@ -112,6 +118,19 @@ class Clusters::ClustersController < Clusters::BaseController
     end
   end
 
+  def create_aws
+    @aws_cluster = ::Clusters::CreateService
+      .new(current_user, create_aws_cluster_params)
+      .execute
+      .present(current_user: current_user)
+
+    if @aws_cluster.persisted?
+      head :created, location: @aws_cluster.show_path
+    else
+      render status: :unprocessable_entity, json: @aws_cluster.errors
+    end
+  end
+
   def create_user
     @user_cluster = ::Clusters::CreateService
       .new(current_user, create_user_cluster_params)
@@ -129,8 +148,37 @@ class Clusters::ClustersController < Clusters::BaseController
     end
   end
 
+  def authorize_aws_role
+    role = current_user.build_aws_role(create_role_params)
+
+    role.save ? respond_201 : respond_422
+  end
+
+  def revoke_aws_role
+    current_user.aws_role&.destroy
+
+    head :no_content
+  end
+
+  def aws_proxy
+    response = Clusters::Aws::ProxyService.new(
+      current_user.aws_role,
+      params: params
+    ).execute
+
+    render json: response.body, status: response.status
+  end
+
   private
 
+  def destroy_params
+    # To be uncomented on https://gitlab.com/gitlab-org/gitlab/merge_requests/16954
+    # This MR got split into other since it was too big.
+    #
+    # params.permit(:cleanup)
+    {}
+  end
+
   def update_params
     if cluster.provided_by_user?
       params.require(:cluster).permit(
@@ -139,6 +187,7 @@ class Clusters::ClustersController < Clusters::BaseController
         :environment_scope,
         :managed,
         :base_domain,
+        :management_project_id,
         platform_kubernetes_attributes: [
           :api_url,
           :token,
@@ -152,6 +201,7 @@ class Clusters::ClustersController < Clusters::BaseController
         :environment_scope,
         :managed,
         :base_domain,
+        :management_project_id,
         platform_kubernetes_attributes: [
           :namespace
         ]
@@ -179,6 +229,28 @@ class Clusters::ClustersController < Clusters::BaseController
       )
   end
 
+  def create_aws_cluster_params
+    params.require(:cluster).permit(
+      :enabled,
+      :name,
+      :environment_scope,
+      :managed,
+      provider_aws_attributes: [
+        :key_name,
+        :role_arn,
+        :region,
+        :vpc_id,
+        :instance_type,
+        :num_nodes,
+        :security_group_id,
+        subnet_ids: []
+      ]).merge(
+        provider_type: :aws,
+        platform_type: :kubernetes,
+        clusterable: clusterable.subject
+      )
+  end
+
   def create_user_cluster_params
     params.require(:cluster).permit(
       :enabled,
@@ -198,6 +270,10 @@ class Clusters::ClustersController < Clusters::BaseController
       )
   end
 
+  def create_role_params
+    params.require(:cluster).permit(:role_arn, :role_external_id)
+  end
+
   def generate_gcp_authorize_url
     params = Feature.enabled?(:create_eks_clusters) ? { provider: :gke } : {}
     state = generate_session_key_redirect(clusterable.new_path(params).to_s)
diff --git a/app/controllers/concerns/confirm_email_warning.rb b/app/controllers/concerns/confirm_email_warning.rb
index 5a4b5897a4f..86df0010665 100644
--- a/app/controllers/concerns/confirm_email_warning.rb
+++ b/app/controllers/concerns/confirm_email_warning.rb
@@ -16,7 +16,7 @@ module ConfirmEmailWarning
 
     email = current_user.unconfirmed_email || current_user.email
 
-    flash.now[:warning] = _("Please check your email (%{email}) to verify that you own this address. Didn't receive it? %{resend_link}. Wrong email address? %{update_link}.").html_safe % {
+    flash.now[:warning] = _("Please check your email (%{email}) to verify that you own this address and unlock the power of CI/CD. Didn't receive it? %{resend_link}. Wrong email address? %{update_link}.").html_safe % {
       email: email,
       resend_link: view_context.link_to(_('Resend it'), user_confirmation_path(user: { email: email }), method: :post),
       update_link: view_context.link_to(_('Update it'), profile_path)
diff --git a/app/controllers/concerns/issuable_collections.rb b/app/controllers/concerns/issuable_collections.rb
index c9a8de0b290..5aa00af8910 100644
--- a/app/controllers/concerns/issuable_collections.rb
+++ b/app/controllers/concerns/issuable_collections.rb
@@ -148,7 +148,7 @@ module IssuableCollections
                                 when 'Issue'
                                   common_attributes + [:project, project: :namespace]
                                 when 'MergeRequest'
-                                  common_attributes + [:target_project, source_project: :route, head_pipeline: :project, target_project: :namespace, latest_merge_request_diff: :merge_request_diff_commits]
+                                  common_attributes + [:target_project, :latest_merge_request_diff, source_project: :route, head_pipeline: :project, target_project: :namespace]
                                 end
   end
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
diff --git a/app/controllers/concerns/lfs_request.rb b/app/controllers/concerns/lfs_request.rb
index 417bb169f39..61072eec535 100644
--- a/app/controllers/concerns/lfs_request.rb
+++ b/app/controllers/concerns/lfs_request.rb
@@ -56,7 +56,7 @@ module LfsRequest
         documentation_url: help_url
       },
       content_type: CONTENT_TYPE,
-      status: 403
+      status: :forbidden
     )
   end
 
@@ -67,7 +67,7 @@ module LfsRequest
         documentation_url: help_url
       },
       content_type: CONTENT_TYPE,
-      status: 404
+      status: :not_found
     )
   end
 
diff --git a/app/controllers/concerns/metrics_dashboard.rb b/app/controllers/concerns/metrics_dashboard.rb
index 62efdacb710..dc392147cb8 100644
--- a/app/controllers/concerns/metrics_dashboard.rb
+++ b/app/controllers/concerns/metrics_dashboard.rb
@@ -3,21 +3,26 @@
 # Provides an action which fetches a metrics dashboard according
 # to the parameters specified by the controller.
 module MetricsDashboard
+  include RenderServiceResults
+  include ChecksCollaboration
+
   extend ActiveSupport::Concern
 
   def metrics_dashboard
     result = dashboard_finder.find(
       project_for_dashboard,
       current_user,
-      metrics_dashboard_params
+      metrics_dashboard_params.to_h.symbolize_keys
     )
 
-    if include_all_dashboards?
-      result[:all_dashboards] = dashboard_finder.find_all_paths(project_for_dashboard)
+    if include_all_dashboards? && result
+      result[:all_dashboards] = all_dashboards
     end
 
     respond_to do |format|
-      if result[:status] == :success
+      if result.nil?
+        format.json { continue_polling_response }
+      elsif result[:status] == :success
         format.json { render dashboard_success_response(result) }
       else
         format.json { render dashboard_error_response(result) }
@@ -27,6 +32,30 @@ module MetricsDashboard
 
   private
 
+  def all_dashboards
+    dashboards = dashboard_finder.find_all_paths(project_for_dashboard)
+    dashboards.map do |dashboard|
+      amend_dashboard(dashboard)
+    end
+  end
+
+  def amend_dashboard(dashboard)
+    project_dashboard = project_for_dashboard && !dashboard[:system_dashboard]
+
+    dashboard[:can_edit] = project_dashboard ? can_edit?(dashboard) : false
+    dashboard[:project_blob_path] = project_dashboard ? dashboard_project_blob_path(dashboard) : nil
+
+    dashboard
+  end
+
+  def dashboard_project_blob_path(dashboard)
+    project_blob_path(project_for_dashboard, File.join(project_for_dashboard.default_branch, dashboard.fetch(:path, "")))
+  end
+
+  def can_edit?(dashboard)
+    can_collaborate_with_project?(project_for_dashboard, ref: project_for_dashboard.default_branch)
+  end
+
   # Override in class to provide arguments to the finder.
   def metrics_dashboard_params
     {}
@@ -56,7 +85,7 @@ module MetricsDashboard
 
   def dashboard_error_response(result)
     {
-      status: result[:http_status],
+      status: result[:http_status] || :bad_request,
       json: result.slice(:all_dashboards, :message, :status)
     }
   end
diff --git a/app/controllers/concerns/milestone_actions.rb b/app/controllers/concerns/milestone_actions.rb
index 672d31ec779..dbc575a1487 100644
--- a/app/controllers/concerns/milestone_actions.rb
+++ b/app/controllers/concerns/milestone_actions.rb
@@ -53,12 +53,10 @@ module MilestoneActions
 
   # rubocop:disable Gitlab/ModuleWithInstanceVariables
   def milestone_redirect_path
-    if @project
-      project_milestone_path(@project, @milestone)
-    elsif @group
-      group_milestone_path(@group, @milestone.safe_title, title: @milestone.title)
+    if @milestone.global_milestone?
+      url_for(action: :show, title: @milestone.title)
     else
-      dashboard_milestone_path(@milestone.safe_title, title: @milestone.title)
+      url_for(action: :show)
     end
   end
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
diff --git a/app/controllers/concerns/preview_markdown.rb b/app/controllers/concerns/preview_markdown.rb
index 2a9729b6ffd..c7c9f2e9b70 100644
--- a/app/controllers/concerns/preview_markdown.rb
+++ b/app/controllers/concerns/preview_markdown.rb
@@ -5,19 +5,10 @@ module PreviewMarkdown
 
   # rubocop:disable Gitlab/ModuleWithInstanceVariables
   def preview_markdown
-    result = PreviewMarkdownService.new(@project, current_user, params).execute
-
-    markdown_params =
-      case controller_name
-      when 'wikis'    then { pipeline: :wiki, project_wiki: @project_wiki, page_slug: params[:id] }
-      when 'snippets' then { skip_project_check: true }
-      when 'groups'   then { group: group }
-      when 'projects' then projects_filter_params
-      else {}
-      end
+    result = PreviewMarkdownService.new(@project, current_user, markdown_service_params).execute
 
     render json: {
-      body: view_context.markdown(result[:text], markdown_params),
+      body: view_context.markdown(result[:text], markdown_context_params),
       references: {
         users: result[:users],
         suggestions: SuggestionSerializer.new.represent_diff(result[:suggestions]),
@@ -26,11 +17,28 @@ module PreviewMarkdown
     }
   end
 
+  private
+
   def projects_filter_params
     {
       issuable_state_filter_enabled: true,
       suggestions_filter_enabled: params[:preview_suggestions].present?
     }
   end
+
+  def markdown_service_params
+    params
+  end
+
+  def markdown_context_params
+    case controller_name
+    when 'wikis'    then { pipeline: :wiki, project_wiki: @project_wiki, page_slug: params[:id] }
+    when 'snippets' then { skip_project_check: true }
+    when 'groups'   then { group: group }
+    when 'projects' then projects_filter_params
+    else {}
+    end.merge(requested_path: params[:path])
+  end
+
   # rubocop:enable Gitlab/ModuleWithInstanceVariables
 end
diff --git a/app/controllers/concerns/redirects_for_missing_path_on_tree.rb b/app/controllers/concerns/redirects_for_missing_path_on_tree.rb
new file mode 100644
index 00000000000..085afbf3975
--- /dev/null
+++ b/app/controllers/concerns/redirects_for_missing_path_on_tree.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module RedirectsForMissingPathOnTree
+  def redirect_to_tree_root_for_missing_path(project, ref, path)
+    redirect_to project_tree_path(project, ref), notice: missing_path_on_ref(path, ref)
+  end
+
+  private
+
+  def missing_path_on_ref(path, ref)
+    _('"%{path}" did not exist on "%{ref}"') % { path: truncate_path(path), ref: ref }
+  end
+
+  def truncate_path(path)
+    path.reverse.truncate(60, separator: "/").reverse
+  end
+end
diff --git a/app/controllers/concerns/renders_commits.rb b/app/controllers/concerns/renders_commits.rb
index ed9b898a2a3..826fae834fa 100644
--- a/app/controllers/concerns/renders_commits.rb
+++ b/app/controllers/concerns/renders_commits.rb
@@ -1,11 +1,11 @@
 # frozen_string_literal: true
 
 module RendersCommits
-  def limited_commits(commits)
-    if commits.size > MergeRequestDiff::COMMITS_SAFE_SIZE
+  def limited_commits(commits, commits_count)
+    if commits_count > MergeRequestDiff::COMMITS_SAFE_SIZE
       [
         commits.first(MergeRequestDiff::COMMITS_SAFE_SIZE),
-        commits.size - MergeRequestDiff::COMMITS_SAFE_SIZE
+        commits_count - MergeRequestDiff::COMMITS_SAFE_SIZE
       ]
     else
       [commits, 0]
@@ -14,9 +14,10 @@ module RendersCommits
 
   # This is used as a helper method in a controller.
   # rubocop: disable Gitlab/ModuleWithInstanceVariables
-  def set_commits_for_rendering(commits)
-    @total_commit_count = commits.size
-    limited, @hidden_commit_count = limited_commits(commits)
+  def set_commits_for_rendering(commits, commits_count: nil)
+    @total_commit_count = commits_count || commits.size
+    limited, @hidden_commit_count = limited_commits(commits, @total_commit_count)
+    commits.each(&:lazy_author) # preload authors
     prepare_commits_for_rendering(limited)
   end
   # rubocop: enable Gitlab/ModuleWithInstanceVariables
diff --git a/app/controllers/concerns/routable_actions.rb b/app/controllers/concerns/routable_actions.rb
index 45f9888a040..1b2e6461dee 100644
--- a/app/controllers/concerns/routable_actions.rb
+++ b/app/controllers/concerns/routable_actions.rb
@@ -47,7 +47,7 @@ module RoutableActions
 
     canonical_path = routable.full_path
     if canonical_path != requested_full_path
-      if canonical_path.casecmp(requested_full_path) != 0
+      if !request.xhr? && request.format.html? && canonical_path.casecmp(requested_full_path) != 0
         flash[:notice] = "#{routable.class.to_s.titleize} '#{requested_full_path}' was moved to '#{canonical_path}'. Please update any links and bookmarks that may still have the old path."
       end
 
diff --git a/app/controllers/concerns/sourcegraph_gon.rb b/app/controllers/concerns/sourcegraph_gon.rb
new file mode 100644
index 00000000000..ab4abd734fb
--- /dev/null
+++ b/app/controllers/concerns/sourcegraph_gon.rb
@@ -0,0 +1,30 @@
+# frozen_string_literal: true
+
+module SourcegraphGon
+  extend ActiveSupport::Concern
+
+  included do
+    before_action :push_sourcegraph_gon, unless: :json_request?
+  end
+
+  private
+
+  def push_sourcegraph_gon
+    return unless sourcegraph_enabled?
+
+    gon.push({
+      sourcegraph: { url: Gitlab::CurrentSettings.sourcegraph_url }
+    })
+  end
+
+  def sourcegraph_enabled?
+    Gitlab::CurrentSettings.sourcegraph_enabled && sourcegraph_enabled_for_project? && current_user&.sourcegraph_enabled
+  end
+
+  def sourcegraph_enabled_for_project?
+    return false unless project && Gitlab::Sourcegraph.feature_enabled?(project)
+    return project.public? if Gitlab::CurrentSettings.sourcegraph_public_only
+
+    true
+  end
+end
diff --git a/app/controllers/dashboard/todos_controller.rb b/app/controllers/dashboard/todos_controller.rb
index 80c0a0d88a8..ebee8e9094e 100644
--- a/app/controllers/dashboard/todos_controller.rb
+++ b/app/controllers/dashboard/todos_controller.rb
@@ -22,7 +22,7 @@ class Dashboard::TodosController < Dashboard::ApplicationController
     respond_to do |format|
       format.html do
         redirect_to dashboard_todos_path,
-                    status: 302,
+                    status: :found,
                     notice: _('To-do item successfully marked as done.')
       end
       format.js { head :ok }
@@ -34,7 +34,7 @@ class Dashboard::TodosController < Dashboard::ApplicationController
     updated_ids = TodoService.new.mark_todos_as_done(@todos, current_user)
 
     respond_to do |format|
-      format.html { redirect_to dashboard_todos_path, status: 302, notice: _('Everything on your to-do list is marked as done.') }
+      format.html { redirect_to dashboard_todos_path, status: :found, notice: _('Everything on your to-do list is marked as done.') }
       format.js { head :ok }
       format.json { render json: todos_counts.merge(updated_ids: updated_ids) }
     end
diff --git a/app/controllers/groups/boards_controller.rb b/app/controllers/groups/boards_controller.rb
index 3c86f3108ab..8c9bf17f017 100644
--- a/app/controllers/groups/boards_controller.rb
+++ b/app/controllers/groups/boards_controller.rb
@@ -6,7 +6,7 @@ class Groups::BoardsController < Groups::ApplicationController
 
   before_action :assign_endpoint_vars
   before_action do
-    push_frontend_feature_flag(:multi_select_board)
+    push_frontend_feature_flag(:multi_select_board, default_enabled: true)
   end
 
   private
diff --git a/app/controllers/groups/group_links_controller.rb b/app/controllers/groups/group_links_controller.rb
new file mode 100644
index 00000000000..7965311c5f1
--- /dev/null
+++ b/app/controllers/groups/group_links_controller.rb
@@ -0,0 +1,34 @@
+# frozen_string_literal: true
+
+class Groups::GroupLinksController < Groups::ApplicationController
+  before_action :check_feature_flag!
+  before_action :authorize_admin_group!
+
+  def create
+    shared_with_group = Group.find(params[:shared_with_group_id]) if params[:shared_with_group_id].present?
+
+    if shared_with_group
+      result = Groups::GroupLinks::CreateService
+                 .new(shared_with_group, current_user, group_link_create_params)
+                 .execute(group)
+
+      return render_404 if result[:http_status] == 404
+
+      flash[:alert] = result[:message] if result[:status] == :error
+    else
+      flash[:alert] = _('Please select a group.')
+    end
+
+    redirect_to group_group_members_path(group)
+  end
+
+  private
+
+  def group_link_create_params
+    params.permit(:shared_group_access, :expires_at)
+  end
+
+  def check_feature_flag!
+    render_404 unless Feature.enabled?(:share_group_with_group)
+  end
+end
diff --git a/app/controllers/groups/labels_controller.rb b/app/controllers/groups/labels_controller.rb
index 26768c628ca..1034ca6cd7b 100644
--- a/app/controllers/groups/labels_controller.rb
+++ b/app/controllers/groups/labels_controller.rb
@@ -63,7 +63,7 @@ class Groups::LabelsController < Groups::ApplicationController
 
     respond_to do |format|
       format.html do
-        redirect_to group_labels_path(@group), status: 302, notice: "#{@label.name} deleted permanently"
+        redirect_to group_labels_path(@group), status: :found, notice: "#{@label.name} deleted permanently"
       end
       format.js
     end
diff --git a/app/controllers/groups/registry/repositories_controller.rb b/app/controllers/groups/registry/repositories_controller.rb
index e09a9e6eb21..cfddd8a3ba9 100644
--- a/app/controllers/groups/registry/repositories_controller.rb
+++ b/app/controllers/groups/registry/repositories_controller.rb
@@ -16,7 +16,7 @@ module Groups
 
             render json: ContainerRepositoriesSerializer
               .new(current_user: current_user)
-              .represent(@images)
+              .represent_read_only(@images)
           end
         end
       end
diff --git a/app/controllers/groups_controller.rb b/app/controllers/groups_controller.rb
index 35e364abba3..755d97b091c 100644
--- a/app/controllers/groups_controller.rb
+++ b/app/controllers/groups_controller.rb
@@ -6,6 +6,7 @@ class GroupsController < Groups::ApplicationController
   include ParamsBackwardCompatibility
   include PreviewMarkdown
   include RecordUserLastActivity
+  extend ::Gitlab::Utils::Override
 
   respond_to :html
 
@@ -24,6 +25,10 @@ class GroupsController < Groups::ApplicationController
 
   before_action :user_actions, only: [:show]
 
+  before_action do
+    push_frontend_feature_flag(:vue_issuables_list, @group)
+  end
+
   skip_cross_project_access_check :index, :new, :create, :edit, :update,
                                   :destroy, :projects
   # When loading show as an atom feed, we render events that could leak cross
@@ -111,7 +116,7 @@ class GroupsController < Groups::ApplicationController
   def destroy
     Groups::DestroyService.new(@group, current_user).async_execute
 
-    redirect_to root_path, status: 302, alert: "Group '#{@group.name}' was scheduled for deletion."
+    redirect_to root_path, status: :found, alert: "Group '#{@group.name}' was scheduled for deletion."
   end
 
   # rubocop: disable CodeReuse/ActiveRecord
@@ -233,6 +238,11 @@ class GroupsController < Groups::ApplicationController
       @group.self_and_descendants.public_or_visible_to_user(current_user)
     end
   end
+
+  override :markdown_service_params
+  def markdown_service_params
+    params.merge(group: group)
+  end
 end
 
 GroupsController.prepend_if_ee('EE::GroupsController')
diff --git a/app/controllers/health_controller.rb b/app/controllers/health_controller.rb
index efd5f0fc607..c6a02250896 100644
--- a/app/controllers/health_controller.rb
+++ b/app/controllers/health_controller.rb
@@ -5,6 +5,11 @@ class HealthController < ActionController::Base
   include RequiresWhitelistedMonitoringClient
 
   CHECKS = [
+    Gitlab::HealthChecks::MasterCheck
+  ].freeze
+
+  ALL_CHECKS = [
+    *CHECKS,
     Gitlab::HealthChecks::DbCheck,
     Gitlab::HealthChecks::Redis::RedisCheck,
     Gitlab::HealthChecks::Redis::CacheCheck,
@@ -14,8 +19,9 @@ class HealthController < ActionController::Base
   ].freeze
 
   def readiness
-    # readiness check is a collection with all above application-level checks
-    render_checks(*CHECKS)
+    # readiness check is a collection of application-level checks
+    # and optionally all service checks
+    render_checks(params[:all] ? ALL_CHECKS : CHECKS)
   end
 
   def liveness
@@ -25,7 +31,7 @@ class HealthController < ActionController::Base
 
   private
 
-  def render_checks(*checks)
+  def render_checks(checks = [])
     result = Gitlab::HealthChecks::Probes::Collection
       .new(*checks)
       .execute
diff --git a/app/controllers/help_controller.rb b/app/controllers/help_controller.rb
index a58235790ad..97895d6461c 100644
--- a/app/controllers/help_controller.rb
+++ b/app/controllers/help_controller.rb
@@ -36,7 +36,7 @@ class HelpController < ApplicationController
           render 'show.html.haml'
         else
           # Force template to Haml
-          render 'errors/not_found.html.haml', layout: 'errors', status: 404
+          render 'errors/not_found.html.haml', layout: 'errors', status: :not_found
         end
       end
 
diff --git a/app/controllers/ldap/omniauth_callbacks_controller.rb b/app/controllers/ldap/omniauth_callbacks_controller.rb
index 4d8875937eb..71a88bf3395 100644
--- a/app/controllers/ldap/omniauth_callbacks_controller.rb
+++ b/app/controllers/ldap/omniauth_callbacks_controller.rb
@@ -4,7 +4,7 @@ class Ldap::OmniauthCallbacksController < OmniauthCallbacksController
   extend ::Gitlab::Utils::Override
 
   def self.define_providers!
-    return unless Gitlab::Auth::LDAP::Config.enabled?
+    return unless Gitlab::Auth::LDAP::Config.sign_in_enabled?
 
     Gitlab::Auth::LDAP::Config.available_servers.each do |server|
       alias_method server['provider_name'], :ldap
@@ -14,6 +14,8 @@ class Ldap::OmniauthCallbacksController < OmniauthCallbacksController
   # We only find ourselves here
   # if the authentication to LDAP was successful.
   def ldap
+    return unless Gitlab::Auth::LDAP::Config.sign_in_enabled?
+
     sign_in_user_flow(Gitlab::Auth::LDAP::User)
   end
 
diff --git a/app/controllers/notification_settings_controller.rb b/app/controllers/notification_settings_controller.rb
index c97fec0a6ee..e5d4a4bb073 100644
--- a/app/controllers/notification_settings_controller.rb
+++ b/app/controllers/notification_settings_controller.rb
@@ -16,12 +16,7 @@ class NotificationSettingsController < ApplicationController
     @notification_setting = current_user.notification_settings.find(params[:id])
     @saved = @notification_setting.update(notification_setting_params_for(@notification_setting.source))
 
-    if params[:hide_label].present?
-      btn_class = params[:project_id].present? ? 'btn-xs' : ''
-      render_response("shared/notifications/_new_button", btn_class)
-    else
-      render_response
-    end
+    render_response
   end
 
   private
@@ -42,7 +37,16 @@ class NotificationSettingsController < ApplicationController
     can?(current_user, ability_name, resource)
   end
 
-  def render_response(response_template = "shared/notifications/_button", btn_class = nil)
+  def render_response
+    btn_class = nil
+
+    if params[:hide_label].present?
+      btn_class = 'btn-xs' if params[:project_id].present?
+      response_template = 'shared/notifications/_new_button'
+    else
+      response_template = 'shared/notifications/_button'
+    end
+
     render json: {
       html: view_to_html_string(response_template, notification_setting: @notification_setting, btn_class: btn_class),
       saved: @saved
diff --git a/app/controllers/oauth/applications_controller.rb b/app/controllers/oauth/applications_controller.rb
index 12dc2d1af1c..8dd51ce1d64 100644
--- a/app/controllers/oauth/applications_controller.rb
+++ b/app/controllers/oauth/applications_controller.rb
@@ -57,7 +57,7 @@ class Oauth::ApplicationsController < Doorkeeper::ApplicationsController
   end
 
   rescue_from ActiveRecord::RecordNotFound do |exception|
-    render "errors/not_found", layout: "errors", status: 404
+    render "errors/not_found", layout: "errors", status: :not_found
   end
 
   def create_application_params
diff --git a/app/controllers/oauth/authorized_applications_controller.rb b/app/controllers/oauth/authorized_applications_controller.rb
index a59ade559b3..9cfa57c53a5 100644
--- a/app/controllers/oauth/authorized_applications_controller.rb
+++ b/app/controllers/oauth/authorized_applications_controller.rb
@@ -13,7 +13,7 @@ class Oauth::AuthorizedApplicationsController < Doorkeeper::AuthorizedApplicatio
     end
 
     redirect_to applications_profile_url,
-                status: 302,
+                status: :found,
                 notice: I18n.t(:notice, scope: [:doorkeeper, :flash, :authorized_applications, :destroy])
   end
 end
diff --git a/app/controllers/omniauth_callbacks_controller.rb b/app/controllers/omniauth_callbacks_controller.rb
index b992972dfb8..eca58748cc5 100644
--- a/app/controllers/omniauth_callbacks_controller.rb
+++ b/app/controllers/omniauth_callbacks_controller.rb
@@ -47,7 +47,7 @@ class OmniauthCallbacksController < Devise::OmniauthCallbacksController
   def omniauth_error
     @provider = params[:provider]
     @error = params[:error]
-    render 'errors/omniauth_error', layout: "oauth_error", status: 422
+    render 'errors/omniauth_error', layout: "oauth_error", status: :unprocessable_entity
   end
 
   def cas3
diff --git a/app/controllers/profiles/preferences_controller.rb b/app/controllers/profiles/preferences_controller.rb
index 42d4d785174..214640a5295 100644
--- a/app/controllers/profiles/preferences_controller.rb
+++ b/app/controllers/profiles/preferences_controller.rb
@@ -47,7 +47,8 @@ class Profiles::PreferencesController < Profiles::ApplicationController
       :preferred_language,
       :time_display_relative,
       :time_format_in_24h,
-      :show_whitespace_in_diffs
+      :show_whitespace_in_diffs,
+      :sourcegraph_enabled
     ]
   end
 end
diff --git a/app/controllers/profiles/u2f_registrations_controller.rb b/app/controllers/profiles/u2f_registrations_controller.rb
index 866c4dee6e2..84ce4a56e64 100644
--- a/app/controllers/profiles/u2f_registrations_controller.rb
+++ b/app/controllers/profiles/u2f_registrations_controller.rb
@@ -4,6 +4,6 @@ class Profiles::U2fRegistrationsController < Profiles::ApplicationController
   def destroy
     u2f_registration = current_user.u2f_registrations.find(params[:id])
     u2f_registration.destroy
-    redirect_to profile_two_factor_auth_path, status: 302, notice: _("Successfully deleted U2F device.")
+    redirect_to profile_two_factor_auth_path, status: :found, notice: _("Successfully deleted U2F device.")
   end
 end
diff --git a/app/controllers/projects/blame_controller.rb b/app/controllers/projects/blame_controller.rb
index 9076bdb9f04..92655d593dd 100644
--- a/app/controllers/projects/blame_controller.rb
+++ b/app/controllers/projects/blame_controller.rb
@@ -3,6 +3,7 @@
 # Controller for viewing a file's blame
 class Projects::BlameController < Projects::ApplicationController
   include ExtractsPath
+  include RedirectsForMissingPathOnTree
 
   before_action :require_non_empty_project
   before_action :assign_ref_vars
@@ -11,7 +12,9 @@ class Projects::BlameController < Projects::ApplicationController
   def show
     @blob = @repository.blob_at(@commit.id, @path)
 
-    return render_404 unless @blob
+    unless @blob
+      return redirect_to_tree_root_for_missing_path(@project, @ref, @path)
+    end
 
     environment_params = @repository.branch_exists?(@ref) ? { ref: @ref } : { commit: @commit }
     @environment = EnvironmentsFinder.new(@project, current_user, environment_params).execute.last
diff --git a/app/controllers/projects/blob_controller.rb b/app/controllers/projects/blob_controller.rb
index 7c3d43fb49a..7c97f771a70 100644
--- a/app/controllers/projects/blob_controller.rb
+++ b/app/controllers/projects/blob_controller.rb
@@ -7,6 +7,9 @@ class Projects::BlobController < Projects::ApplicationController
   include RendersBlob
   include NotesHelper
   include ActionView::Helpers::SanitizeHelper
+  include RedirectsForMissingPathOnTree
+  include SourcegraphGon
+
   prepend_before_action :authenticate_user!, only: [:edit]
 
   around_action :allow_gitaly_ref_name_caching, only: [:show]
@@ -119,7 +122,7 @@ class Projects::BlobController < Projects::ApplicationController
         end
       end
 
-      return render_404
+      return redirect_to_tree_root_for_missing_path(@project, @ref, @path)
     end
   end
 
diff --git a/app/controllers/projects/boards_controller.rb b/app/controllers/projects/boards_controller.rb
index 3b335fa4af4..db05da0bb7f 100644
--- a/app/controllers/projects/boards_controller.rb
+++ b/app/controllers/projects/boards_controller.rb
@@ -8,7 +8,7 @@ class Projects::BoardsController < Projects::ApplicationController
   before_action :authorize_read_board!, only: [:index, :show]
   before_action :assign_endpoint_vars
   before_action do
-    push_frontend_feature_flag(:multi_select_board)
+    push_frontend_feature_flag(:multi_select_board, default_enabled: true)
   end
 
   private
diff --git a/app/controllers/projects/commit_controller.rb b/app/controllers/projects/commit_controller.rb
index 939a09d4fd2..afb670b687b 100644
--- a/app/controllers/projects/commit_controller.rb
+++ b/app/controllers/projects/commit_controller.rb
@@ -8,6 +8,7 @@ class Projects::CommitController < Projects::ApplicationController
   include CreatesCommit
   include DiffForPath
   include DiffHelper
+  include SourcegraphGon
 
   # Authorize
   before_action :require_non_empty_project
diff --git a/app/controllers/projects/environments_controller.rb b/app/controllers/projects/environments_controller.rb
index c053ca19a94..4562296cea0 100644
--- a/app/controllers/projects/environments_controller.rb
+++ b/app/controllers/projects/environments_controller.rb
@@ -13,8 +13,6 @@ class Projects::EnvironmentsController < Projects::ApplicationController
   before_action :verify_api_request!, only: :terminal_websocket_authorize
   before_action :expire_etag_cache, only: [:index]
   before_action only: [:metrics, :additional_metrics, :metrics_dashboard] do
-    push_frontend_feature_flag(:environment_metrics_use_prometheus_endpoint, default_enabled: true)
-    push_frontend_feature_flag(:environment_metrics_additional_panel_types)
     push_frontend_feature_flag(:prometheus_computed_alerts)
   end
 
@@ -133,7 +131,7 @@ class Projects::EnvironmentsController < Projects::ApplicationController
     if environment
       redirect_to environment_metrics_path(environment)
     else
-      render :empty
+      render :empty_metrics
     end
   end
 
@@ -199,8 +197,7 @@ class Projects::EnvironmentsController < Projects::ApplicationController
 
   def metrics_dashboard_params
     params
-      .permit(:embedded, :group, :title, :y_label)
-      .to_h.symbolize_keys
+      .permit(:embedded, :group, :title, :y_label, :dashboard_path, :environment)
       .merge(dashboard_path: params[:dashboard], environment: environment)
   end
 
diff --git a/app/controllers/projects/error_tracking_controller.rb b/app/controllers/projects/error_tracking_controller.rb
index 88d0755f41f..9dea6b663ea 100644
--- a/app/controllers/projects/error_tracking_controller.rb
+++ b/app/controllers/projects/error_tracking_controller.rb
@@ -15,6 +15,23 @@ class Projects::ErrorTrackingController < Projects::ApplicationController
     end
   end
 
+  def details
+    respond_to do |format|
+      format.html
+      format.json do
+        render_issue_detail_json
+      end
+    end
+  end
+
+  def stack_trace
+    respond_to do |format|
+      format.json do
+        render_issue_stack_trace_json
+      end
+    end
+  end
+
   def list_projects
     respond_to do |format|
       format.json do
@@ -29,10 +46,7 @@ class Projects::ErrorTrackingController < Projects::ApplicationController
     service = ErrorTracking::ListIssuesService.new(project, current_user)
     result = service.execute
 
-    unless result[:status] == :success
-      return render json: { message: result[:message] },
-                    status: result[:http_status] || :bad_request
-    end
+    return if handle_errors(result)
 
     render json: {
       errors: serialize_errors(result[:issues]),
@@ -40,6 +54,28 @@ class Projects::ErrorTrackingController < Projects::ApplicationController
     }
   end
 
+  def render_issue_detail_json
+    service = ErrorTracking::IssueDetailsService.new(project, current_user, issue_details_params)
+    result = service.execute
+
+    return if handle_errors(result)
+
+    render json: {
+      error: serialize_detailed_error(result[:issue])
+    }
+  end
+
+  def render_issue_stack_trace_json
+    service = ErrorTracking::IssueLatestEventService.new(project, current_user, issue_details_params)
+    result = service.execute
+
+    return if handle_errors(result)
+
+    render json: {
+      error: serialize_error_event(result[:latest_event])
+    }
+  end
+
   def render_project_list_json
     service = ErrorTracking::ListProjectsService.new(
       project,
@@ -62,10 +98,21 @@ class Projects::ErrorTrackingController < Projects::ApplicationController
     end
   end
 
+  def handle_errors(result)
+    unless result[:status] == :success
+      render json: { message: result[:message] },
+             status: result[:http_status] || :bad_request
+    end
+  end
+
   def list_projects_params
     params.require(:error_tracking_setting).permit([:api_host, :token])
   end
 
+  def issue_details_params
+    params.permit(:issue_id)
+  end
+
   def set_polling_interval
     Gitlab::PollingInterval.set_header(response, interval: POLLING_INTERVAL)
   end
@@ -76,6 +123,18 @@ class Projects::ErrorTrackingController < Projects::ApplicationController
       .represent(errors)
   end
 
+  def serialize_detailed_error(error)
+    ErrorTracking::DetailedErrorSerializer
+      .new(project: project, user: current_user)
+      .represent(error)
+  end
+
+  def serialize_error_event(event)
+    ErrorTracking::ErrorEventSerializer
+      .new(project: project, user: current_user)
+      .represent(event)
+  end
+
   def serialize_projects(projects)
     ErrorTracking::ProjectSerializer
       .new(project: project, user: current_user)
diff --git a/app/controllers/projects/grafana_api_controller.rb b/app/controllers/projects/grafana_api_controller.rb
index 4bdf4c12cac..380a18818ab 100644
--- a/app/controllers/projects/grafana_api_controller.rb
+++ b/app/controllers/projects/grafana_api_controller.rb
@@ -2,6 +2,7 @@
 
 class Projects::GrafanaApiController < Projects::ApplicationController
   include RenderServiceResults
+  include MetricsDashboard
 
   def proxy
     result = ::Grafana::ProxyService.new(
@@ -19,6 +20,10 @@ class Projects::GrafanaApiController < Projects::ApplicationController
 
   private
 
+  def metrics_dashboard_params
+    params.permit(:embedded, :grafana_url)
+  end
+
   def query_params
     params.permit(:query, :start, :end, :step)
   end
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 96cb400950b..009765702ab 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -44,6 +44,7 @@ class Projects::IssuesController < Projects::ApplicationController
 
   before_action do
     push_frontend_feature_flag(:vue_issuable_sidebar, project.group)
+    push_frontend_feature_flag(:release_search_filter, project)
   end
 
   respond_to :html
diff --git a/app/controllers/projects/labels_controller.rb b/app/controllers/projects/labels_controller.rb
index 386a1f00bd2..b7aeab8f5ff 100644
--- a/app/controllers/projects/labels_controller.rb
+++ b/app/controllers/projects/labels_controller.rb
@@ -76,7 +76,7 @@ class Projects::LabelsController < Projects::ApplicationController
     @labels = find_labels
 
     redirect_to project_labels_path(@project),
-                status: 302,
+                status: :found,
                 notice: 'Label was removed'
   end
 
diff --git a/app/controllers/projects/lfs_api_controller.rb b/app/controllers/projects/lfs_api_controller.rb
index a1983bc5462..1273c55b83a 100644
--- a/app/controllers/projects/lfs_api_controller.rb
+++ b/app/controllers/projects/lfs_api_controller.rb
@@ -109,7 +109,7 @@ class Projects::LfsApiController < Projects::GitHttpClientController
           message: lfs_read_only_message
         },
         content_type: LfsRequest::CONTENT_TYPE,
-        status: 403
+        status: :forbidden
       )
     end
   end
diff --git a/app/controllers/projects/merge_requests/creations_controller.rb b/app/controllers/projects/merge_requests/creations_controller.rb
index 808265634da..78dc196b08e 100644
--- a/app/controllers/projects/merge_requests/creations_controller.rb
+++ b/app/controllers/projects/merge_requests/creations_controller.rb
@@ -109,7 +109,13 @@ class Projects::MergeRequests::CreationsController < Projects::MergeRequests::Ap
 
     @target_project = @merge_request.target_project
     @source_project = @merge_request.source_project
-    @commits = set_commits_for_rendering(@merge_request.commits)
+
+    @commits =
+      set_commits_for_rendering(
+        @merge_request.recent_commits.with_latest_pipeline(@merge_request.source_branch),
+          commits_count: @merge_request.commits_count
+      )
+
     @commit = @merge_request.diff_head_commit
 
     # FIXME: We have to assign a presenter to another instance variable
diff --git a/app/controllers/projects/merge_requests/diffs_controller.rb b/app/controllers/projects/merge_requests/diffs_controller.rb
index 4a37dfe5c19..42f9c0522a3 100644
--- a/app/controllers/projects/merge_requests/diffs_controller.rb
+++ b/app/controllers/projects/merge_requests/diffs_controller.rb
@@ -31,6 +31,7 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
 
     options = {
       merge_request: @merge_request,
+      diff_view: diff_view,
       pagination_data: diffs.pagination_data
     }
 
@@ -60,7 +61,9 @@ class Projects::MergeRequests::DiffsController < Projects::MergeRequests::Applic
       render: ->(partial, locals) { view_to_html_string(partial, locals) }
     }
 
-    render json: DiffsSerializer.new(request).represent(@diffs, additional_attributes)
+    options = additional_attributes.merge(diff_view: diff_view)
+
+    render json: DiffsSerializer.new(request).represent(@diffs, options)
   end
 
   def define_diff_vars
diff --git a/app/controllers/projects/merge_requests_controller.rb b/app/controllers/projects/merge_requests_controller.rb
index ff199e05e99..766ec1e33f3 100644
--- a/app/controllers/projects/merge_requests_controller.rb
+++ b/app/controllers/projects/merge_requests_controller.rb
@@ -9,11 +9,12 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   include ToggleAwardEmoji
   include IssuableCollections
   include RecordUserLastActivity
+  include SourcegraphGon
 
   skip_before_action :merge_request, only: [:index, :bulk_update]
   before_action :whitelist_query_limiting, only: [:assign_related_issues, :update]
   before_action :authorize_update_issuable!, only: [:close, :edit, :update, :remove_wip, :sort]
-  before_action :authorize_test_reports!, only: [:test_reports]
+  before_action :authorize_read_actual_head_pipeline!, only: [:test_reports, :exposed_artifacts]
   before_action :set_issuables_index, only: [:index]
   before_action :authenticate_user!, only: [:assign_related_issues]
   before_action :check_user_can_push_to_source_branch!, only: [:rebase]
@@ -23,6 +24,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
 
   before_action do
     push_frontend_feature_flag(:vue_issuable_sidebar, @project.group)
+    push_frontend_feature_flag(:release_search_filter, @project)
   end
 
   around_action :allow_gitaly_ref_name_caching, only: [:index, :show, :discussions]
@@ -89,7 +91,10 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     # Get commits from repository
     # or from cache if already merged
     @commits =
-      set_commits_for_rendering(@merge_request.commits.with_latest_pipeline)
+      set_commits_for_rendering(
+        @merge_request.recent_commits.with_latest_pipeline(@merge_request.source_branch),
+          commits_count: @merge_request.commits_count
+      )
 
     render json: { html: view_to_html_string('projects/merge_requests/_commits') }
   end
@@ -115,6 +120,14 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     reports_response(@merge_request.compare_test_reports)
   end
 
+  def exposed_artifacts
+    if @merge_request.has_exposed_artifacts?
+      reports_response(@merge_request.find_exposed_artifacts)
+    else
+      head :no_content
+    end
+  end
+
   def edit
     define_edit_vars
   end
@@ -218,6 +231,8 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     @merge_request.rebase_async(current_user.id)
 
     head :ok
+  rescue MergeRequest::RebaseLockTimeout => e
+    render json: { merge_error: e.message }, status: :conflict
   end
 
   def discussions
@@ -241,7 +256,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
   end
 
   def merge_params_attributes
-    [:should_remove_source_branch, :commit_message, :squash_commit_message, :squash, :auto_merge_strategy]
+    MergeRequest::KNOWN_MERGE_PARAMS
   end
 
   def auto_merge_requested?
@@ -281,7 +296,7 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
 
     return :sha_mismatch if params[:sha] != @merge_request.diff_head_sha
 
-    @merge_request.update(merge_error: nil, squash: merge_params.fetch(:squash, false))
+    @merge_request.update(merge_error: nil, squash: params.fetch(:squash, false))
 
     if auto_merge_requested?
       if merge_request.auto_merge_enabled?
@@ -353,12 +368,11 @@ class Projects::MergeRequestsController < Projects::MergeRequests::ApplicationCo
     when :error
       render json: { status_reason: report_comparison[:status_reason] }, status: :bad_request
     else
-      render json: { status_reason: 'Unknown error' }, status: :internal_server_error
+      raise "Failed to build comparison response as comparison yielded unknown status '#{report_comparison[:status]}'"
     end
   end
 
-  def authorize_test_reports!
-    # MergeRequest#actual_head_pipeline is the pipeline accessed in MergeRequest#compare_reports.
+  def authorize_read_actual_head_pipeline!
     return render_404 unless can?(current_user, :read_build, merge_request.actual_head_pipeline)
   end
 end
diff --git a/app/controllers/projects/pages_controller.rb b/app/controllers/projects/pages_controller.rb
index 73e629ab7c3..722fc30b3ff 100644
--- a/app/controllers/projects/pages_controller.rb
+++ b/app/controllers/projects/pages_controller.rb
@@ -21,7 +21,7 @@ class Projects::PagesController < Projects::ApplicationController
     respond_to do |format|
       format.html do
         redirect_to project_pages_path(@project),
-                    status: 302,
+                    status: :found,
                     notice: 'Pages were removed'
       end
     end
diff --git a/app/controllers/projects/pages_domains_controller.rb b/app/controllers/projects/pages_domains_controller.rb
index c287e440db0..b693642981e 100644
--- a/app/controllers/projects/pages_domains_controller.rb
+++ b/app/controllers/projects/pages_domains_controller.rb
@@ -8,6 +8,7 @@ class Projects::PagesDomainsController < Projects::ApplicationController
   before_action :domain, except: [:new, :create]
 
   def show
+    redirect_to edit_project_pages_domain_path(@project, @domain)
   end
 
   def new
@@ -23,7 +24,7 @@ class Projects::PagesDomainsController < Projects::ApplicationController
       flash[:alert] = 'Failed to verify domain ownership'
     end
 
-    redirect_to project_pages_domain_path(@project, @domain)
+    redirect_to edit_project_pages_domain_path(@project, @domain)
   end
 
   def edit
@@ -33,7 +34,7 @@ class Projects::PagesDomainsController < Projects::ApplicationController
     @domain = @project.pages_domains.create(create_params)
 
     if @domain.valid?
-      redirect_to project_pages_domain_path(@project, @domain)
+      redirect_to edit_project_pages_domain_path(@project, @domain)
     else
       render 'new'
     end
@@ -42,7 +43,7 @@ class Projects::PagesDomainsController < Projects::ApplicationController
   def update
     if @domain.update(update_params)
       redirect_to project_pages_path(@project),
-        status: 302,
+        status: :found,
         notice: 'Domain was updated'
     else
       render 'edit'
@@ -55,13 +56,21 @@ class Projects::PagesDomainsController < Projects::ApplicationController
     respond_to do |format|
       format.html do
         redirect_to project_pages_path(@project),
-                    status: 302,
+                    status: :found,
                     notice: 'Domain was removed'
       end
       format.js
     end
   end
 
+  def clean_certificate
+    unless @domain.update(user_provided_certificate: nil, user_provided_key: nil)
+      flash[:alert] = @domain.errors.full_messages.join(', ')
+    end
+
+    redirect_to edit_project_pages_domain_path(@project, @domain)
+  end
+
   private
 
   def create_params
@@ -69,7 +78,7 @@ class Projects::PagesDomainsController < Projects::ApplicationController
   end
 
   def update_params
-    params.require(:pages_domain).permit(:user_provided_key, :user_provided_certificate, :auto_ssl_enabled)
+    params.fetch(:pages_domain, {}).permit(:user_provided_key, :user_provided_certificate, :auto_ssl_enabled)
   end
 
   def domain
diff --git a/app/controllers/projects/pipelines_controller.rb b/app/controllers/projects/pipelines_controller.rb
index 106ef1b72c1..4d35353d5f5 100644
--- a/app/controllers/projects/pipelines_controller.rb
+++ b/app/controllers/projects/pipelines_controller.rb
@@ -12,6 +12,7 @@ class Projects::PipelinesController < Projects::ApplicationController
   before_action :authorize_update_pipeline!, only: [:retry, :cancel]
   before_action do
     push_frontend_feature_flag(:hide_dismissed_vulnerabilities)
+    push_frontend_feature_flag(:junit_pipeline_view)
   end
 
   around_action :allow_gitaly_ref_name_caching, only: [:index, :show]
@@ -156,14 +157,21 @@ class Projects::PipelinesController < Projects::ApplicationController
   def test_report
     return unless Feature.enabled?(:junit_pipeline_view, project)
 
-    if pipeline_test_report == :error
-      render json: { status: :error_parsing_report }
-      return
-    end
+    respond_to do |format|
+      format.html do
+        render 'show'
+      end
 
-    render json: TestReportSerializer
-      .new(current_user: @current_user)
-      .represent(pipeline_test_report)
+      format.json do
+        if pipeline_test_report == :error
+          render json: { status: :error_parsing_report }
+        else
+          render json: TestReportSerializer
+            .new(current_user: @current_user)
+            .represent(pipeline_test_report)
+        end
+      end
+    end
   end
 
   private
diff --git a/app/controllers/projects/releases_controller.rb b/app/controllers/projects/releases_controller.rb
index 717df9f09e0..72c82aec31d 100644
--- a/app/controllers/projects/releases_controller.rb
+++ b/app/controllers/projects/releases_controller.rb
@@ -2,12 +2,48 @@
 
 class Projects::ReleasesController < Projects::ApplicationController
   # Authorize
-  before_action :require_non_empty_project
+  before_action :require_non_empty_project, except: [:index]
+  before_action :release, only: %i[edit update]
   before_action :authorize_read_release!
   before_action do
-    push_frontend_feature_flag(:release_edit_page, project)
+    push_frontend_feature_flag(:release_edit_page, project, default_enabled: true)
+    push_frontend_feature_flag(:release_issue_summary, project)
   end
+  before_action :authorize_update_release!, only: %i[edit update]
 
   def index
+    respond_to do |format|
+      format.html do
+        require_non_empty_project
+      end
+      format.json { render json: releases }
+    end
+  end
+
+  protected
+
+  def releases
+    ReleasesFinder.new(@project, current_user).execute
+  end
+
+  def edit
+    respond_to do |format|
+      format.html { render 'edit' }
+    end
+  end
+
+  private
+
+  def authorize_update_release!
+    access_denied! unless Feature.enabled?(:release_edit_page, project, default_enabled: true)
+    access_denied! unless can?(current_user, :update_release, release)
+  end
+
+  def release
+    @release ||= project.releases.find_by_tag!(sanitized_tag_name)
+  end
+
+  def sanitized_tag_name
+    CGI.unescape(params[:tag])
   end
 end
diff --git a/app/controllers/projects/settings/operations_controller.rb b/app/controllers/projects/settings/operations_controller.rb
index 5bf3618b389..1571cb8cd34 100644
--- a/app/controllers/projects/settings/operations_controller.rb
+++ b/app/controllers/projects/settings/operations_controller.rb
@@ -70,7 +70,7 @@ module Projects
             project: [:slug, :name, :organization_slug, :organization_name]
           ],
 
-          grafana_integration_attributes: [:token, :grafana_url]
+          grafana_integration_attributes: [:token, :grafana_url, :enabled]
         }
       end
     end
diff --git a/app/controllers/projects/tags_controller.rb b/app/controllers/projects/tags_controller.rb
index 7d9387b1d94..c89bfd110c4 100644
--- a/app/controllers/projects/tags_controller.rb
+++ b/app/controllers/projects/tags_controller.rb
@@ -84,7 +84,7 @@ class Projects::TagsController < Projects::ApplicationController
 
         format.html do
           redirect_to project_tags_path(@project),
-            alert: @error, status: 303
+            alert: @error, status: :see_other
         end
 
         format.js do
diff --git a/app/controllers/projects/tree_controller.rb b/app/controllers/projects/tree_controller.rb
index 7509cc29a76..eec89afe354 100644
--- a/app/controllers/projects/tree_controller.rb
+++ b/app/controllers/projects/tree_controller.rb
@@ -5,6 +5,7 @@ class Projects::TreeController < Projects::ApplicationController
   include ExtractsPath
   include CreatesCommit
   include ActionView::Helpers::SanitizeHelper
+  include RedirectsForMissingPathOnTree
 
   around_action :allow_gitaly_ref_name_caching, only: [:show]
 
@@ -19,12 +20,9 @@ class Projects::TreeController < Projects::ApplicationController
 
     if tree.entries.empty?
       if @repository.blob_at(@commit.id, @path)
-        return redirect_to(
-          project_blob_path(@project,
-                                      File.join(@ref, @path))
-        )
+        return redirect_to project_blob_path(@project, File.join(@ref, @path))
       elsif @path.present?
-        return render_404
+        return redirect_to_tree_root_for_missing_path(@project, @ref, @path)
       end
     end
 
diff --git a/app/controllers/projects/usage_ping_controller.rb b/app/controllers/projects/usage_ping_controller.rb
new file mode 100644
index 00000000000..ebdf28bd59c
--- /dev/null
+++ b/app/controllers/projects/usage_ping_controller.rb
@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+class Projects::UsagePingController < Projects::ApplicationController
+  before_action :authenticate_user!
+
+  def web_ide_clientside_preview
+    return render_404 unless Gitlab::CurrentSettings.web_ide_clientside_preview_enabled?
+
+    Gitlab::UsageDataCounters::WebIdeCounter.increment_previews_count
+
+    head(200)
+  end
+end
diff --git a/app/controllers/projects/wikis_controller.rb b/app/controllers/projects/wikis_controller.rb
index b187fdb2723..fb06299676c 100644
--- a/app/controllers/projects/wikis_controller.rb
+++ b/app/controllers/projects/wikis_controller.rb
@@ -110,7 +110,7 @@ class Projects::WikisController < Projects::ApplicationController
     WikiPages::DestroyService.new(@project, current_user).execute(@page)
 
     redirect_to project_wiki_path(@project, :home),
-                status: 302,
+                status: :found,
                 notice: _("Page was successfully deleted")
   rescue Gitlab::Git::Wiki::OperationError => e
     @error = e
diff --git a/app/controllers/projects_controller.rb b/app/controllers/projects_controller.rb
index abd19df9a3d..e5dea031bb5 100644
--- a/app/controllers/projects_controller.rb
+++ b/app/controllers/projects_controller.rb
@@ -154,7 +154,7 @@ class ProjectsController < Projects::ApplicationController
 
     redirect_to dashboard_projects_path, status: :found
   rescue Projects::DestroyService::DestroyError => ex
-    redirect_to edit_project_path(@project), status: 302, alert: ex.message
+    redirect_to edit_project_path(@project), status: :found, alert: ex.message
   end
 
   def new_issuable_address
@@ -371,6 +371,7 @@ class ProjectsController < Projects::ApplicationController
       :path,
       :printing_merge_request_link_enabled,
       :public_builds,
+      :remove_source_branch_after_merge,
       :request_access_enabled,
       :runners_token,
       :tag_list,
diff --git a/app/controllers/registrations_controller.rb b/app/controllers/registrations_controller.rb
index 4a746fc915d..5fc7f5c84f0 100644
--- a/app/controllers/registrations_controller.rb
+++ b/app/controllers/registrations_controller.rb
@@ -8,7 +8,7 @@ class RegistrationsController < Devise::RegistrationsController
 
   layout :choose_layout
 
-  skip_before_action :require_role, only: [:welcome, :update_role]
+  skip_before_action :required_signup_info, only: [:welcome, :update_registration]
   prepend_before_action :check_captcha, only: :create
   before_action :whitelist_query_limiting, only: [:destroy]
   before_action :ensure_terms_accepted,
@@ -16,6 +16,7 @@ class RegistrationsController < Devise::RegistrationsController
 
   def new
     if experiment_enabled?(:signup_flow)
+      track_experiment_event(:signup_flow, 'start') # We want this event to be tracked when the user is _in_ the experimental group
       @resource = build_resource
     else
       redirect_to new_user_session_path(anchor: 'register-pane')
@@ -23,6 +24,8 @@ class RegistrationsController < Devise::RegistrationsController
   end
 
   def create
+    track_experiment_event(:signup_flow, 'end') unless experiment_enabled?(:signup_flow) # We want this event to be tracked when the user is _in_ the control group
+
     accept_pending_invitations
 
     super do |new_user|
@@ -42,29 +45,30 @@ class RegistrationsController < Devise::RegistrationsController
     if destroy_confirmation_valid?
       current_user.delete_async(deleted_by: current_user)
       session.try(:destroy)
-      redirect_to new_user_session_path, status: 303, notice: s_('Profiles|Account scheduled for removal.')
+      redirect_to new_user_session_path, status: :see_other, notice: s_('Profiles|Account scheduled for removal.')
     else
-      redirect_to profile_account_path, status: 303, alert: destroy_confirmation_failure_message
+      redirect_to profile_account_path, status: :see_other, alert: destroy_confirmation_failure_message
     end
   end
 
   def welcome
     return redirect_to new_user_registration_path unless current_user
-    return redirect_to stored_location_or_dashboard_or_almost_there_path(current_user) if current_user.role.present?
+    return redirect_to stored_location_or_dashboard_or_almost_there_path(current_user) if current_user.role.present? && !current_user.setup_for_company.nil?
 
-    current_user.name = nil
+    current_user.name = nil if current_user.name == current_user.username
     render layout: 'devise_experimental_separate_sign_up_flow'
   end
 
-  def update_role
-    user_params = params.require(:user).permit(:name, :role)
-    result = ::Users::UpdateService.new(current_user, user_params.merge(user: current_user)).execute
+  def update_registration
+    user_params = params.require(:user).permit(:name, :role, :setup_for_company)
+    result = ::Users::SignupService.new(current_user, user_params).execute
 
     if result[:status] == :success
+      track_experiment_event(:signup_flow, 'end') # We want this event to be tracked when the user is _in_ the experimental group
       set_flash_message! :notice, :signed_up
       redirect_to stored_location_or_dashboard_or_almost_there_path(current_user)
     else
-      redirect_to users_sign_up_welcome_path, alert: result[:message]
+      render :welcome, layout: 'devise_experimental_separate_sign_up_flow'
     end
   end
 
diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index 1c506065b56..0007d5826ba 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -24,6 +24,7 @@ class SessionsController < Devise::SessionsController
   before_action :store_unauthenticated_sessions, only: [:new]
   before_action :save_failed_login, if: :action_new_and_failed_login?
   before_action :load_recaptcha
+  before_action :frontend_tracking_data, only: [:new]
 
   after_action :log_failed_login, if: :action_new_and_failed_login?
 
@@ -269,7 +270,13 @@ class SessionsController < Devise::SessionsController
   end
 
   def ldap_servers
-    @ldap_servers ||= Gitlab::Auth::LDAP::Config.available_servers
+    @ldap_servers ||= begin
+      if Gitlab::Auth::LDAP::Config.sign_in_enabled?
+        Gitlab::Auth::LDAP::Config.available_servers
+      else
+        []
+      end
+    end
   end
 
   def unverified_anonymous_user?
@@ -293,6 +300,11 @@ class SessionsController < Devise::SessionsController
       "standard"
     end
   end
+
+  def frontend_tracking_data
+    # We want tracking data pushed to the frontend when the user is _in_ the control group
+    frontend_experimentation_tracking_data(:signup_flow, 'start') unless experiment_enabled?(:signup_flow)
+  end
 end
 
 SessionsController.prepend_if_ee('EE::SessionsController')
diff --git a/app/controllers/users_controller.rb b/app/controllers/users_controller.rb
index c3c227b08c5..06374736dcf 100644
--- a/app/controllers/users_controller.rb
+++ b/app/controllers/users_controller.rb
@@ -16,7 +16,7 @@ class UsersController < ApplicationController
 
   skip_before_action :authenticate_user!
   prepend_before_action(only: [:show]) { authenticate_sessionless_user!(:rss) }
-  before_action :user, except: [:exists]
+  before_action :user, except: [:exists, :suggests]
   before_action :authorize_read_user_profile!,
                 only: [:calendar, :calendar_activities, :groups, :projects, :contributed_projects, :starred_projects, :snippets]
 
@@ -114,6 +114,14 @@ class UsersController < ApplicationController
     render json: { exists: !!Namespace.find_by_path_or_name(params[:username]) }
   end
 
+  def suggests
+    namespace_path = params[:username]
+    exists = !!Namespace.find_by_path_or_name(namespace_path)
+    suggestions = exists ? [Namespace.clean_path(namespace_path)] : []
+
+    render json: { exists: exists, suggests: suggestions }
+  end
+
   private
 
   def user