Enable real-time issue assignees by default

This also mounts the Action Cable engine all the time.
Mounting the engine has minimal impact on memory so we should just mount
it all the time to reduce configuration complexity.

Changelog: added

app/controllers/projects/issues_controller.rb

@@ -48,9 +48,7 @@ class Projects::IssuesController < Projects::ApplicationController
   end
 
   before_action only: :show do
-    real_time_enabled = Gitlab::ActionCable::Config.in_app? || Feature.enabled?(:real_time_issue_sidebar, @project)
-
-    push_to_gon_attributes(:features, :real_time_issue_sidebar, real_time_enabled)
+    push_frontend_feature_flag(:real_time_issue_sidebar, @project, default_enabled: :yaml)
     push_frontend_feature_flag(:confidential_notes, @project, default_enabled: :yaml)
     push_frontend_feature_flag(:issue_assignees_widget, @project, default_enabled: :yaml)
     push_frontend_feature_flag(:labels_widget, @project, default_enabled: :yaml)

app/services/issues/update_service.rb

@@ -80,7 +80,7 @@ module Issues
       todo_service.reassigned_assignable(issue, current_user, old_assignees)
       track_incident_action(current_user, issue, :incident_assigned)
 
-      if Gitlab::ActionCable::Config.in_app? || Feature.enabled?(:broadcast_issue_updates, issue.project)
+      if Feature.enabled?(:broadcast_issue_updates, issue.project, default_enabled: :yaml)
         GraphqlTriggers.issuable_assignees_updated(issue)
       end
     end

config/environments/test.rb

@@ -59,8 +59,4 @@ Rails.application.configure do
     config.logger = ActiveSupport::TaggedLogging.new(Logger.new(nil))
     config.log_level = :fatal
   end
-
-  # Mount the ActionCable Engine in-app so that we don't have to spawn another Puma
-  # process for feature specs
-  ENV['ACTION_CABLE_IN_APP'] = 'true'
 end

config/feature_flags/development/broadcast_issue_updates.yml

 ---
 name: broadcast_issue_updates
 introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/30732
-rollout_issue_url: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/1210
+rollout_issue_url: https://gitlab.com/gitlab-com/gl-infra/production/-/issues/3413
 milestone: '13.0'
 type: development
 group: group::project management
-default_enabled: false
+default_enabled: true

config/feature_flags/development/real_time_issue_sidebar.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-com/gl-infra/delivery/-/issues/1210
 milestone: '13.0'
 type: development
 group: group::project management
-default_enabled: false
+default_enabled: true

config/initializers/7_prometheus_metrics.rb

@@ -65,7 +65,7 @@ if !Rails.env.test? && Gitlab::Metrics.prometheus_metrics_enabled?
     Gitlab::Metrics::Samplers::DatabaseSampler.initialize_instance.start
     Gitlab::Metrics::Samplers::ThreadsSampler.initialize_instance.start
 
-    if Gitlab::Runtime.action_cable?
+    if Gitlab::Runtime.web_server?
       Gitlab::Metrics::Samplers::ActionCableSampler.instance.start
     end
 

config/initializers/action_cable.rb

@@ -3,8 +3,7 @@
 require 'action_cable/subscription_adapter/redis'
 
 Rails.application.configure do
-  # Mount the ActionCable engine when in-app mode is enabled
-  config.action_cable.mount_path = Gitlab::ActionCable::Config.in_app? ? '/-/cable' : nil
+  config.action_cable.mount_path = '/-/cable'
 
   config.action_cable.url = Gitlab::Utils.append_path(Gitlab.config.gitlab.relative_url_root, '/-/cable')
   config.action_cable.worker_pool_size = Gitlab::ActionCable::Config.worker_pool_size

doc/user/project/issues/managing_issues.md

@@ -380,12 +380,18 @@ You can also use the `/iteration`
 [quick action](../quick_actions.md#issues-merge-requests-and-epics)
 in a comment or description field.
 
-## Real-time sidebar **(FREE SELF)**
+## Real-time sidebar
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/17589) in GitLab 13.3.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/17589) in GitLab 13.3. Disabled by default.
+> - [Enabled on GitLab.com](https://gitlab.com/gitlab-com/gl-infra/production/-/issues/3413) in GitLab 13.9.
+> - [Enabled on self-managed](https://gitlab.com/gitlab-org/gitlab/-/issues/17589) in GitLab 14.5.
 
-Assignees in the sidebar are updated in real time. This feature is **disabled by default**.
-To enable it, you need to enable [Action Cable in-app mode](https://docs.gitlab.com/omnibus/settings/actioncable.html).
+FLAG:
+On self-managed GitLab, by default this feature is available. To hide the feature per project or for your entire instance, ask an administrator to
+[disable the feature flags](../../../administration/feature_flags.md) named `real_time_issue_sidebar` and `broadcast_issue_updates`.
+On GitLab.com, this feature is available.
+
+Assignees in the sidebar are updated in real time.
 
 ## Similar issues
 

lib/gitlab/action_cable/config.rb

@@ -4,10 +4,6 @@ module Gitlab
   module ActionCable
     class Config
       class << self
-        def in_app?
-          Gitlab::Utils.to_boolean(ENV.fetch('ACTION_CABLE_IN_APP', false))
-        end
-
         def worker_pool_size
           ENV.fetch('ACTION_CABLE_WORKER_POOL_SIZE', 4).to_i
         end

lib/gitlab/metrics/samplers/action_cable_sampler.rb

@@ -39,23 +39,14 @@ module Gitlab
 
         def sample
           pool = @action_cable.worker_pool.executor
-          labels = {
-            server_mode: server_mode
-          }
-
-          metrics[:active_connections].set(labels, @action_cable.connections.size)
-          metrics[:pool_min_size].set(labels, pool.min_length)
-          metrics[:pool_max_size].set(labels, pool.max_length)
-          metrics[:pool_current_size].set(labels, pool.length)
-          metrics[:pool_largest_size].set(labels, pool.largest_length)
-          metrics[:pool_completed_tasks].set(labels, pool.completed_task_count)
-          metrics[:pool_pending_tasks].set(labels, pool.queue_length)
-        end
-
-        private
 
-        def server_mode
-          Gitlab::ActionCable::Config.in_app? ? 'in-app' : 'standalone'
+          metrics[:active_connections].set({}, @action_cable.connections.size)
+          metrics[:pool_min_size].set({}, pool.min_length)
+          metrics[:pool_max_size].set({}, pool.max_length)
+          metrics[:pool_current_size].set({}, pool.length)
+          metrics[:pool_largest_size].set({}, pool.largest_length)
+          metrics[:pool_completed_tasks].set({}, pool.completed_task_count)
+          metrics[:pool_pending_tasks].set({}, pool.queue_length)
         end
       end
     end

lib/gitlab/runtime.rb

@@ -63,12 +63,8 @@ module Gitlab
         puma?
       end
 
-      def action_cable?
-        web_server? && (!!defined?(ACTION_CABLE_SERVER) || Gitlab::ActionCable::Config.in_app?)
-      end
-
       def multi_threaded?
-        puma? || sidekiq? || action_cable?
+        puma? || sidekiq?
       end
 
       def puma_in_clustered_mode?
@@ -92,7 +88,7 @@ module Gitlab
           threads += Sidekiq.options[:concurrency] + 2
         end
 
-        if action_cable?
+        if web_server?
           threads += Gitlab::ActionCable::Config.worker_pool_size
         end
 

spec/controllers/projects/issues_controller_spec.rb

@@ -1084,28 +1084,30 @@ RSpec.describe Projects::IssuesController do
       end
 
       context 'real-time sidebar feature flag' do
-        using RSpec::Parameterized::TableSyntax
-
         let_it_be(:project) { create(:project, :public) }
         let_it_be(:issue) { create(:issue, project: project) }
 
-        where(:action_cable_in_app_enabled, :feature_flag_enabled, :gon_feature_flag) do
-          true  | true  | true
-          true  | false | true
-          false | true  | true
-          false | false | false
+        context 'when enabled' do
+          before do
+            stub_feature_flags(real_time_issue_sidebar: true)
           end
 
-        with_them do
+          it 'pushes the correct value to the frontend' do
+            go(id: issue.to_param)
+
+            expect(Gon.features).to include('realTimeIssueSidebar' => true)
+          end
+        end
+
+        context 'when disabled' do
           before do
-            expect(Gitlab::ActionCable::Config).to receive(:in_app?).and_return(action_cable_in_app_enabled)
-            stub_feature_flags(real_time_issue_sidebar: feature_flag_enabled)
+            stub_feature_flags(real_time_issue_sidebar: false)
           end
 
-          it 'broadcasts to the issues channel based on ActionCable and feature flag values' do
+          it 'pushes the correct value to the frontend' do
             go(id: issue.to_param)
 
-            expect(Gon.features).to include('realTimeIssueSidebar' => gon_feature_flag)
+            expect(Gon.features).to include('realTimeIssueSidebar' => false)
           end
         end
       end

spec/lib/gitlab/metrics/samplers/action_cable_sampler_spec.rb

@@ -23,64 +23,46 @@ RSpec.describe Gitlab::Metrics::Samplers::ActionCableSampler do
       allow(pool).to receive(:queue_length).and_return(6)
     end
 
-    shared_examples 'collects metrics' do |expected_labels|
     it 'includes active connections' do
-        expect(subject.metrics[:active_connections]).to receive(:set).with(expected_labels, 0)
+      expect(subject.metrics[:active_connections]).to receive(:set).with({}, 0)
 
       subject.sample
     end
 
     it 'includes minimum worker pool size' do
-        expect(subject.metrics[:pool_min_size]).to receive(:set).with(expected_labels, 1)
+      expect(subject.metrics[:pool_min_size]).to receive(:set).with({}, 1)
 
       subject.sample
     end
 
     it 'includes maximum worker pool size' do
-        expect(subject.metrics[:pool_max_size]).to receive(:set).with(expected_labels, 2)
+      expect(subject.metrics[:pool_max_size]).to receive(:set).with({}, 2)
 
       subject.sample
     end
 
     it 'includes current worker pool size' do
-        expect(subject.metrics[:pool_current_size]).to receive(:set).with(expected_labels, 3)
+      expect(subject.metrics[:pool_current_size]).to receive(:set).with({}, 3)
 
       subject.sample
     end
 
     it 'includes largest worker pool size' do
-        expect(subject.metrics[:pool_largest_size]).to receive(:set).with(expected_labels, 4)
+      expect(subject.metrics[:pool_largest_size]).to receive(:set).with({}, 4)
 
       subject.sample
     end
 
     it 'includes worker pool completed task count' do
-        expect(subject.metrics[:pool_completed_tasks]).to receive(:set).with(expected_labels, 5)
+      expect(subject.metrics[:pool_completed_tasks]).to receive(:set).with({}, 5)
 
       subject.sample
     end
 
     it 'includes worker pool pending task count' do
-        expect(subject.metrics[:pool_pending_tasks]).to receive(:set).with(expected_labels, 6)
+      expect(subject.metrics[:pool_pending_tasks]).to receive(:set).with({}, 6)
 
       subject.sample
     end
   end
-
-    context 'for in-app mode' do
-      before do
-        expect(Gitlab::ActionCable::Config).to receive(:in_app?).and_return(true)
-      end
-
-      it_behaves_like 'collects metrics', server_mode: 'in-app'
-    end
-
-    context 'for standalone mode' do
-      before do
-        expect(Gitlab::ActionCable::Config).to receive(:in_app?).and_return(false)
-      end
-
-      it_behaves_like 'collects metrics', server_mode: 'standalone'
-    end
-  end
 end

spec/lib/gitlab/runtime_spec.rb

@@ -48,10 +48,9 @@ RSpec.describe Gitlab::Runtime do
 
     before do
       stub_const('::Puma', puma_type)
-      stub_env('ACTION_CABLE_IN_APP', 'false')
     end
 
-    it_behaves_like "valid runtime", :puma, 1
+    it_behaves_like "valid runtime", :puma, 1 + Gitlab::ActionCable::Config.worker_pool_size
   end
 
   context "puma with cli_config" do
@@ -61,27 +60,16 @@ RSpec.describe Gitlab::Runtime do
     before do
       stub_const('::Puma', puma_type)
       allow(puma_type).to receive_message_chain(:cli_config, :options).and_return(max_threads: 2, workers: max_workers)
-      stub_env('ACTION_CABLE_IN_APP', 'false')
     end
 
-    it_behaves_like "valid runtime", :puma, 3
+    it_behaves_like "valid runtime", :puma, 3 + Gitlab::ActionCable::Config.worker_pool_size
 
-    context "when ActionCable in-app mode is enabled" do
+    context "when ActionCable worker pool size is configured" do
       before do
-        stub_env('ACTION_CABLE_IN_APP', 'true')
-        stub_env('ACTION_CABLE_WORKER_POOL_SIZE', '3')
+        stub_env('ACTION_CABLE_WORKER_POOL_SIZE', 10)
       end
 
-      it_behaves_like "valid runtime", :puma, 6
-    end
-
-    context "when ActionCable standalone is run" do
-      before do
-        stub_const('ACTION_CABLE_SERVER', true)
-        stub_env('ACTION_CABLE_WORKER_POOL_SIZE', '8')
-      end
-
-      it_behaves_like "valid runtime", :puma, 11
+      it_behaves_like "valid runtime", :puma, 13
     end
 
     describe ".puma_in_clustered_mode?" do

spec/services/issues/update_service_spec.rb

@@ -1248,29 +1248,39 @@ RSpec.describe Issues::UpdateService, :mailer do
       let(:closed_issuable) { create(:closed_issue, project: project) }
     end
 
-    context 'real-time updates' do
-      using RSpec::Parameterized::TableSyntax
-
+    context 'broadcasting issue assignee updates' do
       let(:update_params) { { assignee_ids: [user2.id] } }
 
-      where(:action_cable_in_app_enabled, :feature_flag_enabled, :should_broadcast) do
-        true  | true  | true
-        true  | false | true
-        false | true  | true
-        false | false | false
+      context 'when feature flag is enabled' do
+        before do
+          stub_feature_flags(broadcast_issue_updates: true)
         end
 
-      with_them do
-        it 'broadcasts to the issues channel based on ActionCable and feature flag values' do
-          allow(Gitlab::ActionCable::Config).to receive(:in_app?).and_return(action_cable_in_app_enabled)
-          stub_feature_flags(broadcast_issue_updates: feature_flag_enabled)
-
-          if should_broadcast
+        it 'triggers the GraphQL subscription' do
           expect(GraphqlTriggers).to receive(:issuable_assignees_updated).with(issue)
-          else
+
+          update_issue(update_params)
+        end
+
+        context 'when assignee is not updated' do
+          let(:update_params) { { title: 'Some other title' } }
+
+          it 'does not trigger the GraphQL subscription' do
             expect(GraphqlTriggers).not_to receive(:issuable_assignees_updated).with(issue)
+
+            update_issue(update_params)
+          end
+        end
+      end
+
+      context 'when feature flag is disabled' do
+        before do
+          stub_feature_flags(broadcast_issue_updates: false)
         end
 
+        it 'does not trigger the GraphQL subscription' do
+          expect(GraphqlTriggers).not_to receive(:issuable_assignees_updated).with(issue)
+
           update_issue(update_params)
         end
       end