Introduce `Runtime` class to identify runtime proc

This will serve as the new single access point into
identifying which runtime is active.

Add Process.max_threads method

This will return the maximum concurrency for the given
runtime environment.

Revert to including `defined?` checks for Process

This is based on a reference impl by new relic which they
use to detect the current dispatcher.

Add `name` method, throw if ambiguous

This can be called from an initializer for instance.

Log the current runtime in an initializer

Add `multi_threaded?` and `app_server?` helpers

To allow easier grouping of configuration

Rename `Process` to `Runtime`

And move it into its own file.

Replace all remaining runtime checks with new API

Including a commit body because the danger bot politely asked me
to. There really is nothing else to say.

Prefer `class << self` over `instance_eval`

It seems to be the more widely adopted style.

Simplify `has_instances?` helper method

Fix rubocop offense

Remove max_threads method

This wasn't currently used anywhere and we should define this elsewhere.

Remove references to NR library

This caused some legal questions. We weren't using the instance lookup
before, so it should be OK.

app/services/git/base_hooks_service.rb

@@ -163,7 +163,7 @@ module Git
     end
 
     def logger
-      if Sidekiq.server?
+      if Gitlab::Runtime.sidekiq?
         Sidekiq.logger
       else
         # This service runs in Sidekiq, so this shouldn't ever be

config/application.rb

@@ -22,6 +22,7 @@ module Gitlab
     require_dependency Rails.root.join('lib/gitlab/current_settings')
     require_dependency Rails.root.join('lib/gitlab/middleware/read_only')
     require_dependency Rails.root.join('lib/gitlab/middleware/basic_health_check')
+    require_dependency Rails.root.join('lib/gitlab/runtime')
 
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers
@@ -255,7 +256,7 @@ module Gitlab
     caching_config_hash[:compress] = false
     caching_config_hash[:namespace] = Gitlab::Redis::Cache::CACHE_NAMESPACE
     caching_config_hash[:expires_in] = 2.weeks # Cache should not grow forever
-    if Sidekiq.server? || defined?(::Puma) # threaded context
+    if Gitlab::Runtime.multi_threaded?
       caching_config_hash[:pool_size] = Gitlab::Redis::Cache.pool_size
       caching_config_hash[:pool_timeout] = 1
     end

config/environments/development.rb

@@ -46,7 +46,7 @@ Rails.application.configure do
   # Do not log asset requests
   config.assets.quiet = true
 
-  config.allow_concurrency = defined?(::Puma)
+  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

@@ -75,5 +75,5 @@ Rails.application.configure do
 
   config.eager_load = true
 
-  config.allow_concurrency = defined?(::Puma)
+  config.allow_concurrency = Gitlab::Runtime.multi_threaded?
 end

config/initializers/0_runtime_identify.rb

+# frozen_string_literal: true
+
+begin
+  Gitlab::AppLogger.info("Runtime: #{Gitlab::Runtime.name}")
+rescue => e
+  message = <<-NOTICE
+  \n!! RUNTIME IDENTIFICATION FAILED: #{e}
+  Runtime based configuration settings may not work properly.
+  If you continue to see this error, please file an issue via
+  https://gitlab.com/gitlab-org/gitlab/issues/new
+  NOTICE
+  Gitlab::AppLogger.error(message)
+end

config/initializers/1_settings.rb

@@ -364,7 +364,7 @@ Gitlab.ee do
   # To ensure acceptable performance we only allow feature to be used with
   # multithreaded web-server Puma. This will be removed once download logic is moved
   # to GitLab workhorse
-  Settings.dependency_proxy['enabled'] = false unless defined?(::Puma)
+  Settings.dependency_proxy['enabled'] = false unless Gitlab::Runtime.puma?
 end
 
 #

config/initializers/7_prometheus_metrics.rb

@@ -4,11 +4,11 @@ require 'prometheus/client'
 def prometheus_default_multiproc_dir
   return unless Rails.env.development? || Rails.env.test?
 
-  if Sidekiq.server?
+  if Gitlab::Runtime.sidekiq?
     Rails.root.join('tmp/prometheus_multiproc_dir/sidekiq')
-  elsif defined?(Unicorn::Worker)
+  elsif Gitlab::Runtime.unicorn?
     Rails.root.join('tmp/prometheus_multiproc_dir/unicorn')
-  elsif defined?(::Puma)
+  elsif Gitlab::Runtime.puma?
     Rails.root.join('tmp/prometheus_multiproc_dir/puma')
   else
     Rails.root.join('tmp/prometheus_multiproc_dir')
@@ -55,9 +55,9 @@ if !Rails.env.test? && Gitlab::Metrics.prometheus_metrics_enabled?
   Gitlab::Cluster::LifecycleEvents.on_master_start do
     ::Prometheus::Client.reinitialize_on_pid_change(force: true)
 
-    if defined?(::Unicorn)
+    if Gitlab::Runtime.unicorn?
       Gitlab::Metrics::Samplers::UnicornSampler.instance(Settings.monitoring.unicorn_sampler_interval).start
-    elsif defined?(::Puma)
+    elsif Gitlab::Runtime.puma?
       Gitlab::Metrics::Samplers::PumaSampler.instance(Settings.monitoring.puma_sampler_interval).start
     end
 
@@ -65,7 +65,7 @@ if !Rails.env.test? && Gitlab::Metrics.prometheus_metrics_enabled?
   end
 end
 
-if defined?(::Unicorn) || defined?(::Puma)
+if Gitlab::Runtime.app_server?
   Gitlab::Cluster::LifecycleEvents.on_master_start do
     Gitlab::Metrics::Exporter::WebExporter.instance.start
   end

config/initializers/active_record_lifecycle.rb

@@ -2,7 +2,7 @@
 
 # Don't handle sidekiq configuration as it
 # has its own special active record configuration here
-if defined?(ActiveRecord::Base) && !Sidekiq.server?
+if defined?(ActiveRecord::Base) && !Gitlab::Runtime.sidekiq?
   Gitlab::Cluster::LifecycleEvents.on_worker_start do
     ActiveSupport.on_load(:active_record) do
       ActiveRecord::Base.establish_connection

config/initializers/cluster_events_before_phased_restart.rb

@@ -5,10 +5,8 @@
 #
 # Follow-up the issue: https://gitlab.com/gitlab-org/gitlab/issues/34107
 
-if defined?(::Puma)
+if Gitlab::Runtime.puma?
   Puma::Cluster.prepend(::Gitlab::Cluster::Mixins::PumaCluster)
-end
-
-if defined?(::Unicorn::HttpServer)
+elsif Gitlab::Runtime.unicorn?
   Unicorn::HttpServer.prepend(::Gitlab::Cluster::Mixins::UnicornHttpServer)
 end

config/initializers/database_config.rb

@@ -2,7 +2,7 @@
 
 # when running on puma, scale connection pool size with the number
 # of threads per worker process
-if defined?(::Puma)
+if Gitlab::Runtime.puma?
   db_config = Gitlab::Database.config ||
       Rails.application.config.database_configuration[Rails.env]
   puma_options = Puma.cli_config.options

config/initializers/lograge.rb

 # Only use Lograge for Rails
-unless Sidekiq.server?
+unless Gitlab::Runtime.sidekiq?
   filename = File.join(Rails.root, 'log', "#{Rails.env}_json.log")
 
   Rails.application.configure do

config/initializers/rack_timeout.rb

@@ -9,7 +9,7 @@
 # and it's used only as the last resort. In such case this termination is
 # logged and we should fix the potential timeout issue in the code itself.
 
-if defined?(::Puma) && !Rails.env.test?
+if Gitlab::Runtime.puma? && !Rails.env.test?
   require 'rack/timeout/base'
 
   Gitlab::Application.configure do |config|

config/initializers/tracing.rb

@@ -13,7 +13,7 @@ if Labkit::Tracing.enabled?
   end
 
   # Instrument Sidekiq server calls when running Sidekiq server
-  if Sidekiq.server?
+  if Gitlab::Runtime.sidekiq?
     Sidekiq.configure_server do |config|
       config.server_middleware do |chain|
         chain.add Labkit::Tracing::Sidekiq::ServerMiddleware

config/initializers/validate_puma.rb

 # frozen_string_literal: true
 
-if defined?(::Puma) && ::Puma.cli_config.options[:workers].to_i.zero?
+if Gitlab::Runtime.puma? && ::Puma.cli_config.options[:workers].to_i.zero?
   raise 'Puma is only supported in Cluster-mode: workers > 0'
 end

ee/lib/gitlab/database/load_balancing.rb

@@ -73,7 +73,7 @@ module Gitlab
       # Returns true if load balancing is to be enabled.
       def self.enable?
         return false unless ::License.feature_available?(:db_load_balancing)
-        return false if program_name == 'rake' || Sidekiq.server?
+        return false if program_name == 'rake' || Gitlab::Runtime.sidekiq?
 
         hosts.any? || service_discovery_enabled?
       end

ee/spec/lib/gitlab/database/load_balancing_spec.rb

@@ -109,7 +109,7 @@ describe Gitlab::Database::LoadBalancing do
 
     it 'returns false when Sidekiq is being used' do
       allow(described_class).to receive(:hosts).and_return(%w(foo))
-      allow(Sidekiq).to receive(:server?).and_return(true)
+      allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
 
       expect(described_class.enable?).to eq(false)
     end
@@ -122,14 +122,14 @@ describe Gitlab::Database::LoadBalancing do
 
     it 'returns true when load balancing should be enabled' do
       allow(described_class).to receive(:hosts).and_return(%w(foo))
-      allow(Sidekiq).to receive(:server?).and_return(false)
+      allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(false)
 
       expect(described_class.enable?).to eq(true)
     end
 
     it 'returns true when service discovery is enabled' do
       allow(described_class).to receive(:hosts).and_return([])
-      allow(Sidekiq).to receive(:server?).and_return(false)
+      allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(false)
 
       allow(described_class)
         .to receive(:service_discovery_enabled?)
@@ -161,7 +161,7 @@ describe Gitlab::Database::LoadBalancing do
 
       it 'is enabled' do
         allow(described_class).to receive(:hosts).and_return(%w(foo))
-        allow(Sidekiq).to receive(:server?).and_return(false)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(false)
 
         expect(described_class.enable?).to eq(true)
       end

lib/gitlab.rb

@@ -100,8 +100,8 @@ module Gitlab
   end
 
   def self.process_name
-    return 'sidekiq' if Sidekiq.server?
-    return 'console' if defined?(Rails::Console)
+    return 'sidekiq' if Gitlab::Runtime.sidekiq?
+    return 'console' if Gitlab::Runtime.console?
     return 'test' if Rails.env.test?
 
     'web'

lib/gitlab/cluster/lifecycle_events.rb

@@ -149,10 +149,10 @@ module Gitlab
 
         def in_clustered_environment?
           # Sidekiq doesn't fork
-          return false if Sidekiq.server?
+          return false if Gitlab::Runtime.sidekiq?
 
           # Unicorn always forks
-          return true if defined?(::Unicorn)
+          return true if Gitlab::Runtime.unicorn?
 
           # Puma sometimes forks
           return true if in_clustered_puma?
@@ -162,7 +162,7 @@ module Gitlab
         end
 
         def in_clustered_puma?
-          return false unless defined?(::Puma)
+          return false unless Gitlab::Runtime.puma?
 
           @puma_options && @puma_options[:workers] && @puma_options[:workers] > 0
         end

lib/gitlab/gitaly_client.rb

@@ -29,7 +29,7 @@ module Gitlab
     PEM_REGEX = /\-+BEGIN CERTIFICATE\-+.+?\-+END CERTIFICATE\-+/m.freeze
     SERVER_VERSION_FILE = 'GITALY_SERVER_VERSION'
     MAXIMUM_GITALY_CALLS = 30
-    CLIENT_NAME = (Sidekiq.server? ? 'gitlab-sidekiq' : 'gitlab-web').freeze
+    CLIENT_NAME = (Gitlab::Runtime.sidekiq? ? 'gitlab-sidekiq' : 'gitlab-web').freeze
     GITALY_METADATA_FILENAME = '.gitaly-metadata'
 
     MUTEX = Mutex.new
@@ -383,17 +383,13 @@ module Gitlab
     end
 
     def self.long_timeout
-      if web_app_server?
+      if Gitlab::Runtime.app_server?
         default_timeout
       else
         6.hours
       end
     end
 
-    def self.web_app_server?
-      defined?(::Unicorn) || defined?(::Puma)
-    end
-
     def self.storage_metadata_file_path(storage)
       Gitlab::GitalyClient::StorageSettings.allow_disk_access do
         File.join(

lib/gitlab/gpg.rb

@@ -135,7 +135,7 @@ module Gitlab
     end
 
     def cleanup_time
-      Sidekiq.server? ? BG_CLEANUP_RUNTIME_S : FG_CLEANUP_RUNTIME_S
+      Gitlab::Runtime.sidekiq? ? BG_CLEANUP_RUNTIME_S : FG_CLEANUP_RUNTIME_S
     end
 
     def tmp_keychains_created

lib/gitlab/health_checks/puma_check.rb

@@ -18,7 +18,7 @@ module Gitlab
         end
 
         def check
-          return unless defined?(::Puma)
+          return unless Gitlab::Runtime.puma?
 
           stats = Puma.stats
           stats = JSON.parse(stats)

lib/gitlab/health_checks/unicorn_check.rb

@@ -30,7 +30,7 @@ module Gitlab
         # to change so we can cache the list of servers.
         def http_servers
           strong_memoize(:http_servers) do
-            next unless defined?(::Unicorn::HttpServer)
+            next unless Gitlab::Runtime.unicorn?
 
             ObjectSpace.each_object(::Unicorn::HttpServer).to_a
           end

lib/gitlab/highlight.rb

@@ -68,7 +68,7 @@ module Gitlab
     end
 
     def timeout_time
-      Sidekiq.server? ? TIMEOUT_BACKGROUND : TIMEOUT_FOREGROUND
+      Gitlab::Runtime.sidekiq? ? TIMEOUT_BACKGROUND : TIMEOUT_FOREGROUND
     end
 
     def link_dependencies(text, highlighted_text)

lib/gitlab/metrics/influx_db.rb

@@ -150,7 +150,7 @@ module Gitlab
 
         # Returns the prefix to use for the name of a series.
         def series_prefix
-          @series_prefix ||= Sidekiq.server? ? 'sidekiq_' : 'rails_'
+          @series_prefix ||= Gitlab::Runtime.sidekiq? ? 'sidekiq_' : 'rails_'
         end
 
         # Allow access from other metrics related middlewares

lib/gitlab/metrics/samplers/influx_sampler.rb

@@ -39,14 +39,10 @@ module Gitlab
         end
 
         def add_metric(series, values, tags = {})
-          prefix = sidekiq? ? 'sidekiq_' : 'rails_'
+          prefix = Gitlab::Runtime.sidekiq? ? 'sidekiq_' : 'rails_'
 
           @metrics << Metric.new("#{prefix}#{series}", values, tags)
         end
-
-        def sidekiq?
-          Sidekiq.server?
-        end
       end
     end
   end

lib/gitlab/metrics/samplers/unicorn_sampler.rb

@@ -61,7 +61,7 @@ module Gitlab
         # it takes around 80ms. The instances of HttpServers are not a subject
         # to change so we can cache the list of servers.
         def http_servers
-          return [] unless defined?(::Unicorn::HttpServer)
+          return [] unless Gitlab::Runtime.unicorn?
 
           @http_servers ||= ObjectSpace.each_object(::Unicorn::HttpServer).to_a
         end

lib/gitlab/redis/wrapper.rb

@@ -22,10 +22,10 @@ module Gitlab
         def pool_size
           # heuristic constant 5 should be a config setting somewhere -- related to CPU count?
           size = 5
-          if Sidekiq.server?
+          if Gitlab::Runtime.sidekiq?
             # the pool will be used in a multi-threaded context
             size += Sidekiq.options[:concurrency]
-          elsif defined?(::Puma)
+          elsif Gitlab::Runtime.puma?
             size += Puma.cli_config.options[:max_threads]
           end
 

lib/gitlab/runtime.rb

+# frozen_string_literal: true
+
+module Gitlab
+  # Provides routines to identify the current runtime as which the application
+  # executes, such as whether it is an application server and which one.
+  module Runtime
+    class << self
+      def name
+        matches = []
+        matches << :puma if puma?
+        matches << :unicorn if unicorn?
+        matches << :console if console?
+        matches << :sidekiq if sidekiq?
+
+        raise "Ambiguous process match: #{matches}" if matches.size > 1
+
+        matches.first || :unknown
+      end
+
+      def puma?
+        !!(defined?(::Puma) && bin == 'puma')
+      end
+
+      # For unicorn, we need to check for actual server instances to avoid false positives.
+      def unicorn?
+        !!(defined?(::Unicorn) && defined?(::Unicorn::HttpServer))
+      end
+
+      def sidekiq?
+        !!(defined?(::Sidekiq) && Sidekiq.server? && bin == 'sidekiq')
+      end
+
+      def console?
+        !!defined?(::Rails::Console)
+      end
+
+      def app_server?
+        puma? || unicorn?
+      end
+
+      def multi_threaded?
+        puma? || sidekiq?
+      end
+
+      private
+
+      # Some example values from my system:
+      #   puma: /data/cache/bundle-2.5/bin/puma
+      #   unicorn: unicorn_rails master -E development -c /tmp/unicorn.rb -l 0.0.0.0:8080
+      #   sidekiq: /data/cache/bundle-2.5/bin/sidekiq
+      #   thin: bin/rails
+      #   console: bin/rails
+      def script_name
+        $0
+      end
+
+      def bin
+        File.basename(script_name)
+      end
+    end
+  end
+end

lib/prometheus/pid_provider.rb

@@ -5,11 +5,11 @@ module Prometheus
     extend self
 
     def worker_id
-      if Sidekiq.server?
+      if Gitlab::Runtime.sidekiq?
         sidekiq_worker_id
-      elsif defined?(Unicorn::Worker)
+      elsif Gitlab::Runtime.unicorn?
         unicorn_worker_id
-      elsif defined?(::Puma)
+      elsif Gitlab::Runtime.puma?
         puma_worker_id
       else
         unknown_process_id

spec/initializers/database_config_spec.rb

@@ -16,6 +16,7 @@ describe 'Database config initializer' do
     let(:puma_options) { { max_threads: 8 } }
 
     before do
+      allow(Gitlab::Runtime).to receive(:puma?).and_return(true)
       stub_const("Puma", puma)
       allow(puma).to receive_message_chain(:cli_config, :options).and_return(puma_options)
     end

spec/lib/gitlab/gitaly_client_spec.rb

@@ -26,7 +26,7 @@ describe Gitlab::GitalyClient do
 
     context 'running in Unicorn' do
       before do
-        stub_const('Unicorn', 1)
+        allow(Gitlab::Runtime).to receive(:unicorn?).and_return(true)
       end
 
       it { expect(subject.long_timeout).to eq(55) }
@@ -34,7 +34,7 @@ describe Gitlab::GitalyClient do
 
     context 'running in Puma' do
       before do
-        stub_const('Puma', 1)
+        allow(Gitlab::Runtime).to receive(:puma?).and_return(true)
       end
 
       it { expect(subject.long_timeout).to eq(55) }

spec/lib/gitlab/gpg_spec.rb

@@ -236,7 +236,7 @@ describe Gitlab::Gpg do
 
     context 'when running in Sidekiq' do
       before do
-        allow(Sidekiq).to receive(:server?).and_return(true)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
       end
 
       it_behaves_like 'multiple deletion attempts of the tmp-dir', described_class::BG_CLEANUP_RUNTIME_S

spec/lib/gitlab/health_checks/puma_check_spec.rb

@@ -22,6 +22,7 @@ describe Gitlab::HealthChecks::PumaCheck do
 
   context 'when Puma is not loaded' do
     before do
+      allow(Gitlab::Runtime).to receive(:puma?).and_return(false)
       hide_const('Puma')
     end
 
@@ -33,6 +34,7 @@ describe Gitlab::HealthChecks::PumaCheck do
 
   context 'when Puma is loaded' do
     before do
+      allow(Gitlab::Runtime).to receive(:puma?).and_return(true)
       stub_const('Puma', Module.new)
     end
 

spec/lib/gitlab/health_checks/unicorn_check_spec.rb

@@ -26,6 +26,7 @@ describe Gitlab::HealthChecks::UnicornCheck do
 
   context 'when Unicorn is not loaded' do
     before do
+      allow(Gitlab::Runtime).to receive(:unicorn?).and_return(false)
       hide_const('Unicorn')
     end
 
@@ -39,6 +40,7 @@ describe Gitlab::HealthChecks::UnicornCheck do
     let(:http_server_class) { Struct.new(:worker_processes) }
 
     before do
+      allow(Gitlab::Runtime).to receive(:unicorn?).and_return(true)
       stub_const('Unicorn::HttpServer', http_server_class)
     end
 

spec/lib/gitlab/highlight_spec.rb

@@ -111,7 +111,7 @@ describe Gitlab::Highlight do
       end
 
       it 'utilizes longer timeout for sidekiq' do
-        allow(Sidekiq).to receive(:server?).and_return(true)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
         expect(Timeout).to receive(:timeout).with(described_class::TIMEOUT_BACKGROUND).and_call_original
 
         subject.highlight("Content")

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

@@ -63,7 +63,7 @@ describe Gitlab::Metrics::Samplers::InfluxSampler do
 
   describe '#add_metric' do
     it 'prefixes the series name for a Rails process' do
-      expect(sampler).to receive(:sidekiq?).and_return(false)
+      expect(Gitlab::Runtime).to receive(:sidekiq?).and_return(false)
 
       expect(Gitlab::Metrics::Metric).to receive(:new)
         .with('rails_cats', { value: 10 }, {})
@@ -73,7 +73,7 @@ describe Gitlab::Metrics::Samplers::InfluxSampler do
     end
 
     it 'prefixes the series name for a Sidekiq process' do
-      expect(sampler).to receive(:sidekiq?).and_return(true)
+      expect(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
 
       expect(Gitlab::Metrics::Metric).to receive(:new)
         .with('sidekiq_cats', { value: 10 }, {})

spec/lib/gitlab/runtime_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Runtime do
+  REAL_PATH = $0
+
+  after(:all) do
+    $0 = REAL_PATH
+  end
+
+  context "when unknown" do
+    it "identifies as :unknown" do
+      expect(subject.name).to eq(:unknown)
+    end
+  end
+
+  context "on multiple matches" do
+    before do
+      $0 = '/data/cache/bundle-2.5/bin/puma'
+      stub_const('::Puma', double)
+      stub_const('::Rails::Console', double)
+    end
+
+    it "raises an exception when trying to identify" do
+      expect { subject.name }.to raise_error(RuntimeError, "Ambiguous process match: [:puma, :console]")
+    end
+  end
+
+  context "puma" do
+    let(:puma_type) { double('::Puma') }
+
+    before do
+      $0 = '/data/cache/bundle-2.5/bin/puma'
+      stub_const('::Puma', puma_type)
+    end
+
+    it "identifies itself" do
+      expect(subject.name).to eq(:puma)
+      expect(subject.puma?).to be(true)
+    end
+
+    it "does not identify as others" do
+      expect(subject.unicorn?).to be(false)
+      expect(subject.sidekiq?).to be(false)
+      expect(subject.console?).to be(false)
+    end
+  end
+
+  context "unicorn" do
+    let(:unicorn_type) { Module.new }
+    let(:unicorn_server_type) { Class.new }
+
+    before do
+      $0 = 'unicorn_rails master -E development -c /tmp/unicorn.rb -l 0.0.0.0:8080'
+      stub_const('::Unicorn', unicorn_type)
+      stub_const('::Unicorn::HttpServer', unicorn_server_type)
+    end
+
+    it "identifies itself" do
+      expect(subject.name).to eq(:unicorn)
+      expect(subject.unicorn?).to be(true)
+    end
+
+    it "does not identify as others" do
+      expect(subject.puma?).to be(false)
+      expect(subject.sidekiq?).to be(false)
+      expect(subject.console?).to be(false)
+    end
+  end
+
+  context "sidekiq" do
+    let(:sidekiq_type) { double('::Sidekiq') }
+
+    before do
+      $0 = '/data/cache/bundle-2.5/bin/sidekiq'
+      stub_const('::Sidekiq', sidekiq_type)
+      allow(sidekiq_type).to receive(:server?).and_return(true)
+    end
+
+    it "identifies itself" do
+      expect(subject.name).to eq(:sidekiq)
+      expect(subject.sidekiq?).to be(true)
+    end
+
+    it "does not identify as others" do
+      expect(subject.unicorn?).to be(false)
+      expect(subject.puma?).to be(false)
+      expect(subject.console?).to be(false)
+    end
+  end
+
+  context "console" do
+    let(:console_type) { double('::Rails::Console') }
+
+    before do
+      $0 = 'bin/rails'
+      stub_const('::Rails::Console', console_type)
+    end
+
+    it "identifies itself" do
+      expect(subject.name).to eq(:console)
+      expect(subject.console?).to be(true)
+    end
+
+    it "does not identify as others" do
+      expect(subject.unicorn?).to be(false)
+      expect(subject.sidekiq?).to be(false)
+      expect(subject.puma?).to be(false)
+    end
+  end
+end

spec/lib/prometheus/pid_provider_spec.rb

@@ -6,16 +6,13 @@ describe Prometheus::PidProvider do
   describe '.worker_id' do
     subject { described_class.worker_id }
 
-    let(:sidekiq_module) { Module.new }
-
     before do
-      allow(sidekiq_module).to receive(:server?).and_return(false)
-      stub_const('Sidekiq', sidekiq_module)
+      allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(false)
     end
 
     context 'when running in Sidekiq server mode' do
       before do
-        expect(Sidekiq).to receive(:server?).and_return(true)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
       end
 
       context 'in a clustered setup' do
@@ -33,8 +30,7 @@ describe Prometheus::PidProvider do
 
     context 'when running in Unicorn mode' do
       before do
-        stub_const('Unicorn::Worker', Class.new)
-        hide_const('Puma')
+        allow(Gitlab::Runtime).to receive(:unicorn?).and_return(true)
 
         expect(described_class).to receive(:process_name)
           .at_least(:once)
@@ -94,8 +90,7 @@ describe Prometheus::PidProvider do
 
     context 'when running in Puma mode' do
       before do
-        stub_const('Puma', Module.new)
-        hide_const('Unicorn::Worker')
+        allow(Gitlab::Runtime).to receive(:puma?).and_return(true)
 
         expect(described_class).to receive(:process_name)
           .at_least(:once)
@@ -116,11 +111,6 @@ describe Prometheus::PidProvider do
     end
 
     context 'when running in unknown mode' do
-      before do
-        hide_const('Puma')
-        hide_const('Unicorn::Worker')
-      end
-
       it { is_expected.to eq "process_#{Process.pid}" }
     end
   end

spec/services/git/branch_push_service_spec.rb

@@ -108,7 +108,7 @@ describe Git::BranchPushService, services: true do
       end
 
       it 'reports an error' do
-        allow(Sidekiq).to receive(:server?).and_return(true)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
         expect(Sidekiq.logger).to receive(:warn)
 
         expect { subject }.not_to change { Ci::Pipeline.count }

spec/support/redis/redis_shared_examples.rb

@@ -118,7 +118,7 @@ RSpec.shared_examples "redis_shared_examples" do
 
     context 'when running not on sidekiq workers' do
       before do
-        allow(Sidekiq).to receive(:server?).and_return(false)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(false)
       end
 
       it 'instantiates a connection pool with size 5' do
@@ -130,7 +130,7 @@ RSpec.shared_examples "redis_shared_examples" do
 
     context 'when running on sidekiq workers' do
       before do
-        allow(Sidekiq).to receive(:server?).and_return(true)
+        allow(Gitlab::Runtime).to receive(:sidekiq?).and_return(true)
         allow(Sidekiq).to receive(:options).and_return({ concurrency: 18 })
       end