Merge branch 'revert-99071b7b' into 'master'

Enable running of ActionCable in in-app mode

See merge request gitlab-org/gitlab!35225

config/application.rb

@@ -17,6 +17,7 @@ module Gitlab
   class Application < Rails::Application
     require_dependency Rails.root.join('lib/gitlab')
     require_dependency Rails.root.join('lib/gitlab/utils')
+    require_dependency Rails.root.join('lib/gitlab/action_cable/config')
     require_dependency Rails.root.join('lib/gitlab/redis/wrapper')
     require_dependency Rails.root.join('lib/gitlab/redis/cache')
     require_dependency Rails.root.join('lib/gitlab/redis/queues')

config/environments/development.rb

@@ -49,8 +49,6 @@ Rails.application.configure do
   # Do not log asset requests
   config.assets.quiet = true
 
-  config.allow_concurrency = Gitlab::Runtime.multi_threaded?
-
   # BetterErrors live shell (REPL) on every stack frame
   BetterErrors::Middleware.allow_ip!("127.0.0.1/0")
 

config/environments/production.rb

@@ -77,6 +77,4 @@ Rails.application.configure do
   config.action_mailer.raise_delivery_errors = true
 
   config.eager_load = true
-
-  config.allow_concurrency = Gitlab::Runtime.multi_threaded?
 end

config/environments/test.rb

@@ -54,4 +54,8 @@ 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/gitlab.yml.example

@@ -1105,11 +1105,6 @@ production: &base
     #   host: localhost
     #   port: 3808
 
-  ## ActionCable settings
-  action_cable:
-    # Number of threads used to process ActionCable connection callbacks and channel actions
-    # worker_pool_size: 4
-
   ## Monitoring
   # Built in monitoring settings
   monitoring:

config/initializers/1_settings.rb

@@ -737,12 +737,6 @@ Settings.webpack.dev_server['enabled'] ||= false
 Settings.webpack.dev_server['host']    ||= 'localhost'
 Settings.webpack.dev_server['port']    ||= 3808
 
-#
-# ActionCable settings
-#
-Settings['action_cable'] ||= Settingslogic.new({})
-Settings.action_cable['worker_pool_size'] ||= 4
-
 #
 # Monitoring settings
 #

config/initializers/action_cable.rb

@@ -3,11 +3,11 @@
 require 'action_cable/subscription_adapter/redis'
 
 Rails.application.configure do
-  # We only mount the ActionCable engine in tests where we run it in-app
-  # For other environments, we run it on a standalone Puma server
-  config.action_cable.mount_path = Rails.env.test? ? '/-/cable' : nil
+  # 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.url = Gitlab::Utils.append_path(Gitlab.config.gitlab.relative_url_root, '/-/cable')
-  config.action_cable.worker_pool_size = Gitlab.config.action_cable.worker_pool_size
+  config.action_cable.worker_pool_size = Gitlab::ActionCable::Config.worker_pool_size
 end
 
 # https://github.com/rails/rails/blob/bb5ac1623e8de08c1b7b62b1368758f0d3bb6379/actioncable/lib/action_cable/subscription_adapter/redis.rb#L18

lib/gitlab/action_cable/config.rb

+# frozen_string_literal: true
+
+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
+      end
+    end
+  end
+end

lib/gitlab/runtime.rb

@@ -37,7 +37,7 @@ module Gitlab
       end
 
       def puma?
-        !!defined?(::Puma) && !defined?(ACTION_CABLE_SERVER)
+        !!defined?(::Puma)
       end
 
       # For unicorn, we need to check for actual server instances to avoid false positives.
@@ -70,11 +70,11 @@ module Gitlab
       end
 
       def web_server?
-        puma? || unicorn? || action_cable?
+        puma? || unicorn?
       end
 
       def action_cable?
-        !!defined?(ACTION_CABLE_SERVER)
+        web_server? && (!!defined?(ACTION_CABLE_SERVER) || Gitlab::ActionCable::Config.in_app?)
       end
 
       def multi_threaded?
@@ -82,19 +82,21 @@ module Gitlab
       end
 
       def max_threads
-        main_thread = 1
+        threads = 1 # main thread
 
-        if action_cable?
-          Gitlab::Application.config.action_cable.worker_pool_size
-        elsif puma?
-          Puma.cli_config.options[:max_threads]
+        if puma?
+          threads += Puma.cli_config.options[:max_threads]
         elsif sidekiq?
           # An extra thread for the poller in Sidekiq Cron:
           # https://github.com/ondrejbartas/sidekiq-cron#under-the-hood
-          Sidekiq.options[:concurrency] + 1
-        else
-          0
-        end + main_thread
+          threads += Sidekiq.options[:concurrency] + 1
+        end
+
+        if action_cable?
+          threads += Gitlab::ActionCable::Config.worker_pool_size
+        end
+
+        threads
       end
     end
   end

spec/lib/gitlab/runtime_spec.rb

@@ -48,18 +48,47 @@ 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)
+      stub_env('ACTION_CABLE_IN_APP', 'false')
     end
 
     it_behaves_like "valid runtime", :puma, 3
+
+    context "when ActionCable in-app mode is enabled" do
+      before do
+        stub_env('ACTION_CABLE_IN_APP', 'true')
+        stub_env('ACTION_CABLE_WORKER_POOL_SIZE', '3')
+      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
+    end
   end
 
   context "unicorn" do
     before do
       stub_const('::Unicorn', Module.new)
       stub_const('::Unicorn::HttpServer', Class.new)
+      stub_env('ACTION_CABLE_IN_APP', 'false')
     end
 
     it_behaves_like "valid runtime", :unicorn, 1
+
+    context "when ActionCable in-app mode is enabled" do
+      before do
+        stub_env('ACTION_CABLE_IN_APP', 'true')
+        stub_env('ACTION_CABLE_WORKER_POOL_SIZE', '3')
+      end
+
+      it_behaves_like "valid runtime", :unicorn, 4
+    end
   end
 
   context "sidekiq" do
@@ -105,17 +134,4 @@ RSpec.describe Gitlab::Runtime do
 
     it_behaves_like "valid runtime", :rails_runner, 1
   end
-
-  context "action_cable" do
-    before do
-      stub_const('ACTION_CABLE_SERVER', true)
-      stub_const('::Puma', Module.new)
-
-      allow(Gitlab::Application).to receive_message_chain(:config, :action_cable, :worker_pool_size).and_return(8)
-    end
-
-    it "reports its maximum concurrency based on ActionCable's worker pool size" do
-      expect(subject.max_threads).to eq(9)
-    end
-  end
 end