Run tests in parallel via parallel_tests

Uses the parallel_tests gem to execute tests in multiple processes
simultaneously on the same machine.

Adds the `--parallel` CLI option that instructs the QA framework
to use the parallel_tests executable.

Tests need access to global state contained in `Runtime::Scenario`
so when `--parallel` is invoked `Runtime::Scenario` is serialized
to an environment variable, which is passed to parallel_tests,
and then deserialized in `spec_helper`.

14 files changed, 172 insertions, 32 deletions

diff --git a/qa/.rspec_parallel b/qa/.rspec_parallel
new file mode 100644
index 00000000000..e5927927eaa
--- /dev/null
+++ b/qa/.rspec_parallel
@@ -0,0 +1,5 @@
+--color
+--format documentation
+--format ParallelTests::RSpec::SummaryLogger --out tmp/spec_summary.log
+--format ParallelTests::RSpec::RuntimeLogger --out tmp/parallel_runtime_rspec.log
+--require spec_helper
diff --git a/qa/Gemfile b/qa/Gemfile
index 12994b85322..c46be8a0362 100644
--- a/qa/Gemfile
+++ b/qa/Gemfile
@@ -1,5 +1,6 @@
 source 'https://rubygems.org'
 
+gem 'gitlab-qa'
 gem 'pry-byebug', '~> 3.5.1', platform: :mri
 gem 'capybara', '~> 2.16.1'
 gem 'capybara-screenshot', '~> 1.0.18'
@@ -11,3 +12,4 @@ gem 'nokogiri', '~> 1.10.3'
 gem 'rspec-retry', '~> 0.6.1'
 gem 'faker', '~> 1.6', '>= 1.6.6'
 gem 'knapsack', '~> 1.17'
+gem 'parallel_tests', '~> 2.29'
diff --git a/qa/Gemfile.lock b/qa/Gemfile.lock
index 6b0635ed0e2..73aabf2c6ad 100644
--- a/qa/Gemfile.lock
+++ b/qa/Gemfile.lock
@@ -35,6 +35,7 @@ GEM
     faker (1.9.3)
       i18n (>= 0.7)
     ffi (1.9.25)
+    gitlab-qa (4.0.0)
     http-cookie (1.0.3)
       domain_name (~> 0.5)
     i18n (0.9.1)
@@ -53,6 +54,9 @@ GEM
     netrc (0.11.0)
     nokogiri (1.10.3)
       mini_portile2 (~> 2.4.0)
+    parallel (1.17.0)
+    parallel_tests (2.29.0)
+      parallel
     pry (0.11.3)
       coderay (~> 1.1.0)
       method_source (~> 0.9.0)
@@ -104,8 +108,10 @@ DEPENDENCIES
   capybara (~> 2.16.1)
   capybara-screenshot (~> 1.0.18)
   faker (~> 1.6, >= 1.6.6)
+  gitlab-qa
   knapsack (~> 1.17)
   nokogiri (~> 1.10.3)
+  parallel_tests (~> 2.29)
   pry-byebug (~> 3.5.1)
   rake (~> 12.3.0)
   rspec (~> 3.7)
diff --git a/qa/qa.rb b/qa/qa.rb
index 10d44b6f6d9..be73776425b 100644
--- a/qa/qa.rb
+++ b/qa/qa.rb
@@ -360,6 +360,7 @@ module QA
   module Specs
     autoload :Config, 'qa/specs/config'
     autoload :Runner, 'qa/specs/runner'
+    autoload :ParallelRunner, 'qa/specs/parallel_runner'
 
     module Helpers
       autoload :Quarantine, 'qa/specs/helpers/quarantine'
diff --git a/qa/qa/runtime/browser.rb b/qa/qa/runtime/browser.rb
index ed0779b93cc..2987bb1a213 100644
--- a/qa/qa/runtime/browser.rb
+++ b/qa/qa/runtime/browser.rb
@@ -13,6 +13,8 @@ module QA
 
       NotRespondingError = Class.new(RuntimeError)
 
+      CAPYBARA_MAX_WAIT_TIME = 10
+
       def initialize
         self.class.configure!
       end
@@ -43,6 +45,8 @@ module QA
           end
         end
 
+        Capybara.server_port = 9887 + ENV['TEST_ENV_NUMBER'].to_i
+
         return if Capybara.drivers.include?(:chrome)
 
         Capybara.register_driver QA::Runtime::Env.browser do |app|
@@ -119,7 +123,7 @@ module QA
         Capybara.configure do |config|
           config.default_driver = QA::Runtime::Env.browser
           config.javascript_driver = QA::Runtime::Env.browser
-          config.default_max_wait_time = 10
+          config.default_max_wait_time = CAPYBARA_MAX_WAIT_TIME
           # https://github.com/mattheworiordan/capybara-screenshot/issues/164
           config.save_path = ::File.expand_path('../../tmp', __dir__)
         end
diff --git a/qa/qa/runtime/env.rb b/qa/qa/runtime/env.rb
index 96f337dc081..d50f618ff82 100644
--- a/qa/qa/runtime/env.rb
+++ b/qa/qa/runtime/env.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'gitlab/qa'
+
 module QA
   module Runtime
     module Env
@@ -7,6 +9,8 @@ module QA
 
       attr_writer :personal_access_token, :ldap_username, :ldap_password
 
+      ENV_VARIABLES = Gitlab::QA::Runtime::Env::ENV_VARIABLES
+
       # The environment variables used to indicate if the environment under test
       # supports the given feature
       SUPPORTED_FEATURES = {
@@ -201,6 +205,10 @@ module QA
         enabled?(ENV[SUPPORTED_FEATURES[feature]], default: true)
       end
 
+      def runtime_scenario_attributes
+        ENV['QA_RUNTIME_SCENARIO_ATTRIBUTES']
+      end
+
       private
 
       def remote_grid_credentials
diff --git a/qa/qa/runtime/scenario.rb b/qa/qa/runtime/scenario.rb
index 5067322804b..3662ebe671b 100644
--- a/qa/qa/runtime/scenario.rb
+++ b/qa/qa/runtime/scenario.rb
@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'json'
+
 module QA
   module Runtime
     ##
@@ -24,6 +26,10 @@ module QA
         end
       end
 
+      def from_env(var)
+        JSON.parse(Runtime::Env.runtime_scenario_attributes).each { |k, v| define(k, v) }
+      end
+
       def method_missing(name, *)
         raise ArgumentError, "Scenario attribute `#{name}` not defined!"
       end
diff --git a/qa/qa/scenario/shared_attributes.rb b/qa/qa/scenario/shared_attributes.rb
index 40d5c6b1ff1..52f50ec8c27 100644
--- a/qa/qa/scenario/shared_attributes.rb
+++ b/qa/qa/scenario/shared_attributes.rb
@@ -7,6 +7,7 @@ module QA
 
       attribute :gitlab_address, '--address URL', 'Address of the instance to test'
       attribute :enable_feature, '--enable-feature FEATURE_FLAG', 'Enable a feature before running tests'
+      attribute :parallel, '--parallel', 'Execute tests in parallel'
     end
   end
 end
diff --git a/qa/qa/specs/parallel_runner.rb b/qa/qa/specs/parallel_runner.rb
new file mode 100644
index 00000000000..b92fdb610b6
--- /dev/null
+++ b/qa/qa/specs/parallel_runner.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require 'open3'
+
+module QA
+  module Specs
+    module ParallelRunner
+      module_function
+
+      def run(args)
+        unless args.include?('--')
+          index = args.index { |opt| opt.include?('features') }
+
+          args.insert(index, '--') if index
+        end
+
+        env = {}
+        Runtime::Env::ENV_VARIABLES.each_key do |key|
+          env[key] = ENV[key] if ENV[key]
+        end
+        env['QA_RUNTIME_SCENARIO_ATTRIBUTES'] = Runtime::Scenario.attributes.to_json
+        env['GITLAB_QA_ACCESS_TOKEN'] = Runtime::API::Client.new(:gitlab).personal_access_token unless env['GITLAB_QA_ACCESS_TOKEN']
+
+        cmd = "bundle exec parallel_test -t rspec --combine-stderr --serialize-stdout -- #{args.flatten.join(' ')}"
+        ::Open3.popen2e(env, cmd) do |_, out, wait|
+          out.each { |line| puts line }
+
+          exit wait.value.exitstatus
+        end
+      end
+    end
+  end
+end
diff --git a/qa/qa/specs/runner.rb b/qa/qa/specs/runner.rb
index f1cb9378de8..6aa08cf77b4 100644
--- a/qa/qa/specs/runner.rb
+++ b/qa/qa/specs/runner.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
+require 'knapsack'
 require 'rspec/core'
 require 'rspec/expectations'
-require 'knapsack'
 
 module QA
   module Specs
@@ -17,44 +17,56 @@ module QA
         @options = []
       end
 
-      def perform
-        args = []
-        args.push('--tty') if tty
+      def paths_from_knapsack
+        allocator = Knapsack::AllocatorBuilder.new(Knapsack::Adapters::RSpecAdapter).allocator
+
+        QA::Runtime::Logger.info ''
+        QA::Runtime::Logger.info 'Report specs:'
+        QA::Runtime::Logger.info allocator.report_node_tests.join(', ')
+        QA::Runtime::Logger.info ''
+        QA::Runtime::Logger.info 'Leftover specs:'
+        QA::Runtime::Logger.info allocator.leftover_node_tests.join(', ')
+        QA::Runtime::Logger.info ''
+
+        ['--', allocator.node_tests]
+      end
+
+      def rspec_tags
+        tags_for_rspec = []
 
         if tags.any?
-          tags.each { |tag| args.push(['--tag', tag.to_s]) }
+          tags.each { |tag| tags_for_rspec.push(['--tag', tag.to_s]) }
         else
-          args.push(%w[--tag ~orchestrated]) unless (%w[-t --tag] & options).any?
+          tags_for_rspec.push(%w[--tag ~orchestrated]) unless (%w[-t --tag] & options).any?
         end
 
-        args.push(%w[--tag ~skip_signup_disabled]) if QA::Runtime::Env.signup_disabled?
+        tags_for_rspec.push(%w[--tag ~skip_signup_disabled]) if QA::Runtime::Env.signup_disabled?
 
         QA::Runtime::Env.supported_features.each_key do |key|
-          args.push(["--tag", "~requires_#{key}"]) unless QA::Runtime::Env.can_test? key
+          tags_for_rspec.push(%W[--tag ~requires_#{key}]) unless QA::Runtime::Env.can_test? key
         end
 
-        args.push(options)
+        tags_for_rspec
+      end
 
-        Runtime::Browser.configure!
+      def perform
+        args = []
+        args.push('--tty') if tty
+        args.push(rspec_tags)
+        args.push(options)
 
         if Runtime::Env.knapsack?
-          allocator = Knapsack::AllocatorBuilder.new(Knapsack::Adapters::RSpecAdapter).allocator
-
-          QA::Runtime::Logger.info ''
-          QA::Runtime::Logger.info 'Report specs:'
-          QA::Runtime::Logger.info allocator.report_node_tests.join(', ')
-          QA::Runtime::Logger.info ''
-          QA::Runtime::Logger.info 'Leftover specs:'
-          QA::Runtime::Logger.info allocator.leftover_node_tests.join(', ')
-          QA::Runtime::Logger.info ''
-
-          args.push(['--', allocator.node_tests])
+          args.push(paths_from_knapsack)
         else
           args.push(DEFAULT_TEST_PATH_ARGS) unless options.any? { |opt| opt =~ %r{/features/} }
         end
 
-        RSpec::Core::Runner.run(args.flatten, $stderr, $stdout).tap do |status|
-          abort if status.nonzero?
+        if Runtime::Scenario.attributes[:parallel]
+          ParallelRunner.run(args.flatten)
+        else
+          RSpec::Core::Runner.run(args.flatten, $stderr, $stdout).tap do |status|
+            abort if status.nonzero?
+          end
         end
       end
     end
diff --git a/qa/spec/page/logging_spec.rb b/qa/spec/page/logging_spec.rb
index 0f1ed039149..92a4f7b40e6 100644
--- a/qa/spec/page/logging_spec.rb
+++ b/qa/spec/page/logging_spec.rb
@@ -91,26 +91,26 @@ describe QA::Support::Page::Logging do
 
   it 'logs has_element?' do
     expect { subject.has_element?(:element) }
-      .to output(/has_element\? :element \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_element\? :element \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_element? with text' do
     expect { subject.has_element?(:element, text: "some text") }
-      .to output(/has_element\? :element with text \"some text\" \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_element\? :element with text \"some text\" \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_no_element?' do
     allow(page).to receive(:has_no_css?).and_return(true)
 
     expect { subject.has_no_element?(:element) }
-      .to output(/has_no_element\? :element \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_no_element\? :element \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_no_element? with text' do
     allow(page).to receive(:has_no_css?).and_return(true)
 
     expect { subject.has_no_element?(:element, text: "more text") }
-      .to output(/has_no_element\? :element with text \"more text\" \(wait: 2\) returned: true/).to_stdout_from_any_process
+      .to output(/has_no_element\? :element with text \"more text\" \(wait: #{QA::Runtime::Browser::CAPYBARA_MAX_WAIT_TIME}\) returned: true/).to_stdout_from_any_process
   end
 
   it 'logs has_text?' do
diff --git a/qa/spec/spec_helper.rb b/qa/spec/spec_helper.rb
index f25dbf3a8ab..21bfd2876a9 100644
--- a/qa/spec/spec_helper.rb
+++ b/qa/spec/spec_helper.rb
@@ -8,6 +8,10 @@ if ENV['CI'] && QA::Runtime::Env.knapsack? && !ENV['NO_KNAPSACK']
   Knapsack::Adapters::RSpecAdapter.bind
 end
 
+QA::Runtime::Browser.configure!
+
+QA::Runtime::Scenario.from_env(QA::Runtime::Env.runtime_scenario_attributes) if QA::Runtime::Env.runtime_scenario_attributes
+
 %w[helpers shared_examples].each do |d|
   Dir[::File.join(__dir__, d, '**', '*.rb')].each { |f| require f }
 end
diff --git a/qa/spec/specs/parallel_runner_spec.rb b/qa/spec/specs/parallel_runner_spec.rb
new file mode 100644
index 00000000000..67d94a1f648
--- /dev/null
+++ b/qa/spec/specs/parallel_runner_spec.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+describe QA::Specs::ParallelRunner do
+  include Helpers::StubENV
+
+  before do
+    allow(QA::Runtime::Scenario).to receive(:attributes).and_return(parallel: true)
+    stub_env('GITLAB_QA_ACCESS_TOKEN', 'skip_token_creation')
+  end
+
+  it 'passes args to parallel_tests' do
+    expect_cli_arguments(['--tag', '~orchestrated', *QA::Specs::Runner::DEFAULT_TEST_PATH_ARGS])
+
+    subject.run(['--tag', '~orchestrated', *QA::Specs::Runner::DEFAULT_TEST_PATH_ARGS])
+  end
+
+  it 'passes a given test path to parallel_tests and adds a separator' do
+    expect_cli_arguments(%w[-- qa/specs/features/foo])
+
+    subject.run(%w[qa/specs/features/foo])
+  end
+
+  it 'passes tags and test paths to parallel_tests and adds a separator' do
+    expect_cli_arguments(%w[--tag smoke -- qa/specs/features/foo qa/specs/features/bar])
+
+    subject.run(%w[--tag smoke qa/specs/features/foo qa/specs/features/bar])
+  end
+
+  it 'passes tags and test paths with separators to parallel_tests' do
+    expect_cli_arguments(%w[-- --tag smoke -- qa/specs/features/foo qa/specs/features/bar])
+
+    subject.run(%w[-- --tag smoke -- qa/specs/features/foo qa/specs/features/bar])
+  end
+
+  it 'passes supported environment variables' do
+    # Test only env vars starting with GITLAB because some of the others
+    # affect how the runner behaves, and we're not concerned with those
+    # behaviors in this test
+    gitlab_env_vars = QA::Runtime::Env::ENV_VARIABLES.reject { |v| !v.start_with?('GITLAB') }
+
+    gitlab_env_vars.each do |k, v|
+      stub_env(k, v)
+    end
+
+    gitlab_env_vars['QA_RUNTIME_SCENARIO_ATTRIBUTES'] = '{"parallel":true}'
+
+    expect_cli_arguments([], gitlab_env_vars)
+
+    subject.run([])
+  end
+
+  def expect_cli_arguments(arguments, env = { 'QA_RUNTIME_SCENARIO_ATTRIBUTES' => '{"parallel":true}' })
+    cmd = "bundle exec parallel_test -t rspec --combine-stderr --serialize-stdout -- #{arguments.join(' ')}"
+    expect(Open3).to receive(:popen2e)
+      .with(hash_including(env), cmd)
+      .and_return(0)
+  end
+end
diff --git a/qa/spec/specs/runner_spec.rb b/qa/spec/specs/runner_spec.rb
index f94145d148e..6c533c6dc7d 100644
--- a/qa/spec/specs/runner_spec.rb
+++ b/qa/spec/specs/runner_spec.rb
@@ -58,11 +58,11 @@ describe QA::Specs::Runner do
       end
     end
 
-    context 'when "-- qa/specs/features/foo" is set as options' do
-      subject { described_class.new.tap { |runner| runner.options = %w[-- qa/specs/features/foo] } }
+    context 'when "--tag smoke" and "qa/specs/features/foo" are set as options' do
+      subject { described_class.new.tap { |runner| runner.options = %w[--tag smoke qa/specs/features/foo] } }
 
-      it 'passes the given tests path and excludes the orchestrated tag' do
-        expect_rspec_runner_arguments(['--tag', '~orchestrated', '--', 'qa/specs/features/foo'])
+      it 'focuses on the given tag and includes the path without excluding the orchestrated tag' do
+        expect_rspec_runner_arguments(['--tag', 'smoke', 'qa/specs/features/foo'])
 
         subject.perform
       end