Set feature flag via command line

First attempt at allowing a feature flag to be set via the command line
when running tests. This will enable the flag, run the tests, and then
disable the flag.

Using OptionParser meant changing how scenarios get the instance
address, so this also allows the address to be set as a command line
option. It's backwards compatible (you can still provide the address
as the command line option after the scenario)

qa/README.md

@@ -55,16 +55,19 @@ You can also supply specific tests to run as another parameter. For example, to
 run the repository-related specs, you can execute:
 
 ```
-bin/qa Test::Instance::All http://localhost qa/specs/features/repository/
+bin/qa Test::Instance::All http://localhost -- qa/specs/features/browser_ui/3_create/repository
 ```
 
 Since the arguments would be passed to `rspec`, you could use all `rspec`
 options there. For example, passing `--backtrace` and also line number:
 
 ```
-bin/qa Test::Instance::All http://localhost qa/specs/features/project/create_spec.rb:3 --backtrace
+bin/qa Test::Instance::All http://localhost -- qa/specs/features/browser_ui/3_create/merge_request/create_merge_request_spec.rb:6 --backtrace
 ```
 
+Note that the separator `--` is required; all subsequent options will be
+ignored by the QA framework and passed to `rspec`.
+
 ### Overriding the authenticated user
 
 Unless told otherwise, the QA tests will run as the default `root` user seeded
@@ -117,7 +120,7 @@ tests that are expected to fail while a fix is in progress (similar to how
  can be used).
 
 ```
-bin/qa Test::Instance::All http://localhost --tag quarantine
+bin/qa Test::Instance::All http://localhost -- --tag quarantine
 ```
 
 If `quarantine` is used with other tags, tests will only be run if they have at
@@ -128,3 +131,25 @@ For example, suppose one test has `:smoke` and `:quarantine` metadata, and
 another test has `:ldap` and `:quarantine` metadata. If the tests are run with
 `--tag smoke --tag quarantine`, only the first test will run. The test with
 `:ldap` will not run even though it also has `:quarantine`.
+
+### Running tests with a feature flag enabled
+
+Tests can be run with with a feature flag enabled by using the command-line
+option `--enable-feature FEATURE_FLAG`. For example, to enable the feature flag
+that enforces Gitaly request limits, you would use the command:
+
+```
+bin/qa Test::Instance::All http://localhost --enable-feature gitaly_enforce_requests_limits
+```
+
+This will instruct the QA framework to enable the `gitaly_enforce_requests_limits`
+feature flag ([via the API](https://docs.gitlab.com/ee/api/features.html)), run
+all the tests in the `Test::Instance::All` scenario, and then disable the
+feature flag again.
+
+Note: the QA framework doesn't currently allow you to easily toggle a feature
+flag during a single test, [as you can in unit tests](https://docs.gitlab.com/ee/development/feature_flags.html#specs),
+but [that capability is planned](https://gitlab.com/gitlab-org/quality/team-tasks/issues/77).
+
+Note also that the `--` separator isn't used because `--enable-feature` is a QA
+framework option, not an `rspec` option.
\ No newline at end of file

qa/qa.rb

@@ -17,6 +17,7 @@ module Runtime
     autoload :Env, 'qa/runtime/env'
     autoload :Address, 'qa/runtime/address'
     autoload :Path, 'qa/runtime/path'
+    autoload :Feature, 'qa/runtime/feature'
     autoload :Fixtures, 'qa/runtime/fixtures'
     autoload :Logger, 'qa/runtime/logger'
 
@@ -89,6 +90,7 @@ module Scenario
     autoload :Bootable, 'qa/scenario/bootable'
     autoload :Actable, 'qa/scenario/actable'
     autoload :Template, 'qa/scenario/template'
+    autoload :SharedAttributes, 'qa/scenario/shared_attributes'
 
     ##
     # Test scenario entrypoints.

qa/qa/resource/api_fabricator.rb

@@ -8,9 +8,6 @@ module Resource
     module ApiFabricator
       include Capybara::DSL
 
-      HTTP_STATUS_OK = 200
-      HTTP_STATUS_CREATED = 201
-
       ResourceNotFoundError = Class.new(RuntimeError)
       ResourceFabricationFailedError = Class.new(RuntimeError)
       ResourceURLMissingError = Class.new(RuntimeError)

qa/qa/runtime/address.rb

@@ -15,6 +15,13 @@ def host
           @instance.to_s
         end
       end
+
+      def self.valid?(value)
+        uri = URI.parse(value)
+        uri.is_a?(URI::HTTP) && !uri.host.nil?
+      rescue URI::InvalidURIError
+        false
+      end
     end
   end
 end

qa/qa/runtime/feature.rb

+# frozen_string_literal: true
+
+module QA
+  module Runtime
+    module Feature
+      extend self
+      extend Support::Api
+
+      SetFeatureError = Class.new(RuntimeError)
+
+      def enable(key)
+        QA::Runtime::Logger.info("Enabling feature: #{key}")
+        set_feature(key, true)
+      end
+
+      def disable(key)
+        QA::Runtime::Logger.info("Disabling feature: #{key}")
+        set_feature(key, false)
+      end
+
+      private
+
+      def api_client
+        @api_client ||= Runtime::API::Client.new(:gitlab)
+      end
+
+      def set_feature(key, value)
+        request = Runtime::API::Request.new(api_client, "/features/#{key}")
+        response = post(request.url, { value: value })
+        unless response.code == QA::Support::Api::HTTP_STATUS_CREATED
+          raise SetFeatureError, "Setting feature flag #{key} to #{value} failed with `#{response}`."
+        end
+      end
+    end
+  end
+end

qa/qa/scenario/bootable.rb

@@ -23,7 +23,7 @@ def launch!(argv)
 
           arguments.parse!(argv)
 
-          self.perform(Runtime::Scenario.attributes, *arguments.default_argv)
+          self.perform(Runtime::Scenario.attributes, *argv)
         end
 
         private
@@ -33,7 +33,13 @@ def attribute(name, arg, desc = '')
         end
 
         def options
-          @options ||= []
+          # Scenario options/attributes are global. There's only ever one
+          # scenario at a time, but they can be inherited and we want scenarios
+          # to share the attributes of their ancestors. For example, `Mattermost`
+          # inherits from `Test::Instance::All` but if this were an instance
+          # variable then `Mattermost` wouldn't have access to the attributes
+          # in `All`
+          @@options ||= [] # rubocop:disable Style/ClassVars
         end
 
         def has_attributes?

qa/qa/scenario/shared_attributes.rb

+# frozen_string_literal: true
+
+module QA
+  module Scenario
+    module SharedAttributes
+      include Bootable
+
+      attribute :gitlab_address, '--address URL', 'Address of the instance to test'
+      attribute :enable_feature, '--enable-feature FEATURE_FLAG', 'Enable a feature before running tests'
+    end
+  end
+end

qa/qa/scenario/template.rb

@@ -18,19 +18,44 @@ def focus
         end
       end
 
-      def perform(address, *rspec_options)
-        Runtime::Scenario.define(:gitlab_address, address)
+      def perform(options, *args)
+        extract_address(:gitlab_address, options, args)
 
         ##
         # Perform before hooks, which are different for CE and EE
         #
         Runtime::Release.perform_before_hooks
 
+        Runtime::Feature.enable(options[:enable_feature]) if options.key?(:enable_feature)
+
         Specs::Runner.perform do |specs|
           specs.tty = true
           specs.tags = self.class.focus
-          specs.options = rspec_options if rspec_options.any?
+          specs.options = args if args.any?
         end
+      ensure
+        Runtime::Feature.disable(options[:enable_feature]) if options.key?(:enable_feature)
+      end
+
+      def extract_option(name, options, args)
+        option = if options.key?(name)
+                   options[name]
+                 else
+                   args.shift
+                 end
+
+        Runtime::Scenario.define(name, option)
+
+        option
+      end
+
+      # For backwards-compatibility, if the gitlab instance address is not
+      # specified as an option parsed by OptionParser, it can be specified as
+      # the first argument
+      def extract_address(name, options, args)
+        address = extract_option(name, options, args)
+
+        raise ::ArgumentError, "The address provided for `#{name}` is not valid: #{address}" unless Runtime::Address.valid?(address)
       end
     end
   end

qa/qa/scenario/test/instance/all.rb

@@ -8,6 +8,7 @@ module Test
       module Instance
         class All < Template
           include Bootable
+          include SharedAttributes
         end
       end
     end

qa/qa/scenario/test/instance/smoke.rb

@@ -8,6 +8,7 @@ module Instance
         #
         class Smoke < Template
           include Bootable
+          include SharedAttributes
 
           tags :smoke
         end

qa/qa/scenario/test/integration/mattermost.rb

@@ -9,10 +9,13 @@ module Integration
         class Mattermost < Test::Instance::All
           tags :mattermost
 
-          def perform(address, mattermost, *rspec_options)
-            Runtime::Scenario.define(:mattermost_address, mattermost)
+          attribute :mattermost_address, '--mattermost-address URL', 'Address of the Mattermost server'
 
-            super(address, *rspec_options)
+          def perform(options, *args)
+            extract_address(:gitlab_address, options, args)
+            extract_address(:mattermost_address, options, args)
+
+            super(options, *args)
           end
         end
       end

qa/qa/support/api.rb

 module QA
   module Support
     module Api
+      HTTP_STATUS_OK = 200
+      HTTP_STATUS_CREATED = 201
+
       def post(url, payload)
         RestClient::Request.execute(
           method: :post,

qa/spec/runtime/feature_spec.rb

+# frozen_string_literal: true
+
+describe QA::Runtime::Feature do
+  let(:api_client) { double('QA::Runtime::API::Client') }
+  let(:request) { Struct.new(:url).new('http://api') }
+  let(:response) { Struct.new(:code).new(201) }
+
+  before do
+    allow(described_class).to receive(:api_client).and_return(api_client)
+  end
+
+  describe '.enable' do
+    it 'enables a feature flag' do
+      expect(QA::Runtime::API::Request)
+        .to receive(:new)
+        .with(api_client, "/features/a-flag")
+        .and_return(request)
+      expect(described_class)
+        .to receive(:post)
+        .with(request.url, { value: true })
+        .and_return(response)
+
+      subject.enable('a-flag')
+    end
+  end
+
+  describe '.disable' do
+    it 'disables a feature flag' do
+      expect(QA::Runtime::API::Request)
+        .to receive(:new)
+        .with(api_client, "/features/a-flag")
+        .and_return(request)
+      expect(described_class)
+        .to receive(:post)
+        .with(request.url, { value: false })
+        .and_return(response)
+
+      subject.disable('a-flag')
+    end
+  end
+end

qa/spec/runtime/scenario_spec.rb

@@ -13,6 +13,14 @@
       .to eq(my_attribute: 'some-value', another_attribute: 'another-value')
   end
 
+  it 'replaces an existing attribute' do
+    subject.define(:my_attribute, 'some-value')
+    subject.define(:my_attribute, 'another-value')
+
+    expect(subject.my_attribute).to eq 'another-value'
+    expect(subject.attributes).to eq(my_attribute: 'another-value')
+  end
+
   it 'raises error when attribute is not known' do
     expect { subject.invalid_accessor }
       .to raise_error ArgumentError, /invalid_accessor/

qa/spec/scenario/bootable_spec.rb

@@ -4,14 +4,21 @@
       .include(described_class)
   end
 
+  before do
+    allow(subject).to receive(:options).and_return([])
+    allow(QA::Runtime::Scenario).to receive(:attributes).and_return({})
+  end
+
   it 'makes it possible to define the scenario attribute' do
     subject.class_eval do
       attribute :something, '--something SOMETHING', 'Some attribute'
       attribute :another, '--another ANOTHER', 'Some other attribute'
     end
 
+    # If we run just this test from the command line it fails unless
+    # we include the command line args that we use to select this test.
     expect(subject).to receive(:perform)
-      .with(something: 'test', another: 'other')
+      .with({ something: 'test', another: 'other' })
 
     subject.launch!(%w[--another other --something test])
   end

qa/spec/scenario/template_spec.rb

+# frozen_string_literal: true
+
+describe QA::Scenario::Template do
+  let(:feature) { spy('Runtime::Feature') }
+  let(:release) { spy('Runtime::Release') }
+
+  before do
+    stub_const('QA::Runtime::Release', release)
+    stub_const('QA::Runtime::Feature', feature)
+    allow(QA::Specs::Runner).to receive(:perform)
+    allow(QA::Runtime::Address).to receive(:valid?).and_return(true)
+  end
+
+  it 'allows a feature to be enabled' do
+    subject.perform({ enable_feature: 'a-feature' })
+
+    expect(feature).to have_received(:enable).with('a-feature')
+  end
+
+  it 'ensures an enabled feature is disabled afterwards' do
+    allow(QA::Specs::Runner).to receive(:perform).and_raise('failed test')
+
+    expect { subject.perform({ enable_feature: 'a-feature' }) }.to raise_error('failed test')
+
+    expect(feature).to have_received(:enable).with('a-feature')
+    expect(feature).to have_received(:disable).with('a-feature')
+  end
+end

qa/spec/scenario/test/integration/github_spec.rb

@@ -12,7 +12,7 @@
       let(:tags) { [:github] }
 
       it 'requires a GitHub access token' do
-        subject.perform('gitlab_address')
+        subject.perform(args)
 
         expect(env).to have_received(:require_github_access_token!)
       end

qa/spec/scenario/test/integration/mattermost_spec.rb

@@ -4,14 +4,21 @@
   context '#perform' do
     it_behaves_like 'a QA scenario class' do
       let(:args) { %w[gitlab_address mattermost_address] }
+      let(:args) do
+        {
+          gitlab_address: 'http://gitlab_address',
+          mattermost_address: 'http://mattermost_address'
+        }
+      end
+      let(:named_options) { %w[--address http://gitlab_address --mattermost-address http://mattermost_address] }
       let(:tags) { [:mattermost] }
       let(:options) { ['path1']}
 
       it 'requires a GitHub access token' do
-        subject.perform(*args)
+        subject.perform(args)
 
         expect(attributes).to have_received(:define)
-          .with(:mattermost_address, 'mattermost_address')
+          .with(:mattermost_address, 'http://mattermost_address')
       end
     end
   end

qa/spec/shared_examples/scenario_shared_examples.rb

@@ -2,19 +2,23 @@
 
 shared_examples 'a QA scenario class' do
   let(:attributes) { spy('Runtime::Scenario') }
-  let(:release) { spy('Runtime::Release') }
   let(:runner) { spy('Specs::Runner') }
+  let(:release) { spy('Runtime::Release') }
+  let(:feature) { spy('Runtime::Feature') }
 
-  let(:args) { ['gitlab_address'] }
+  let(:args) { { gitlab_address: 'http://gitlab_address' } }
+  let(:named_options) { %w[--address http://gitlab_address] }
   let(:tags) { [] }
   let(:options) { %w[path1 path2] }
 
   before do
+    stub_const('QA::Specs::Runner', runner)
     stub_const('QA::Runtime::Release', release)
     stub_const('QA::Runtime::Scenario', attributes)
-    stub_const('QA::Specs::Runner', runner)
+    stub_const('QA::Runtime::Feature', feature)
 
     allow(runner).to receive(:perform).and_yield(runner)
+    allow(QA::Runtime::Address).to receive(:valid?).and_return(true)
   end
 
   it 'responds to perform' do
@@ -22,28 +26,48 @@
   end
 
   it 'sets an address of the subject' do
-    subject.perform(*args)
+    subject.perform(args)
 
-    expect(attributes).to have_received(:define).with(:gitlab_address, 'gitlab_address')
+    expect(attributes).to have_received(:define).with(:gitlab_address, 'http://gitlab_address').at_least(:once)
   end
 
   it 'performs before hooks' do
-    subject.perform(*args)
+    subject.perform(args)
 
     expect(release).to have_received(:perform_before_hooks)
   end
 
   it 'sets tags on runner' do
-    subject.perform(*args)
+    subject.perform(args)
 
     expect(runner).to have_received(:tags=).with(tags)
   end
 
   context 'specifying RSpec options' do
     it 'sets options on runner' do
-      subject.perform(*args, *options)
+      subject.perform(args, *options)
 
       expect(runner).to have_received(:options=).with(options)
     end
   end
+
+  context 'with named command-line options' do
+    it 'converts options to attributes' do
+      described_class.launch!(named_options)
+
+      args do |k, v|
+        expect(attributes).to have_received(:define).with(k, v)
+      end
+    end
+
+    it 'raises an error if the option is invalid' do
+      expect { described_class.launch!(['--foo']) }.to raise_error(OptionParser::InvalidOption)
+    end
+
+    it 'passes on options after --' do
+      expect(described_class).to receive(:perform).with(attributes, *%w[--tag quarantine])
+
+      described_class.launch!(named_options.push(*%w[-- --tag quarantine]))
+    end
+  end
 end