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)

10 files changed, 102 insertions, 11 deletions

diff --git a/qa/qa/resource/api_fabricator.rb b/qa/qa/resource/api_fabricator.rb
index 98eebac0880..de04467ff5b 100644
--- a/qa/qa/resource/api_fabricator.rb
+++ b/qa/qa/resource/api_fabricator.rb
@@ -8,9 +8,6 @@ module QA
     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)
diff --git a/qa/qa/runtime/address.rb b/qa/qa/runtime/address.rb
index ffad3974b02..af0537dc17c 100644
--- a/qa/qa/runtime/address.rb
+++ b/qa/qa/runtime/address.rb
@@ -15,6 +15,13 @@ module QA
           @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
diff --git a/qa/qa/runtime/feature.rb b/qa/qa/runtime/feature.rb
new file mode 100644
index 00000000000..1b4ae7adbbe
--- /dev/null
+++ b/qa/qa/runtime/feature.rb
@@ -0,0 +1,36 @@
+# 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
diff --git a/qa/qa/scenario/bootable.rb b/qa/qa/scenario/bootable.rb
index dd12ea6d492..038418be023 100644
--- a/qa/qa/scenario/bootable.rb
+++ b/qa/qa/scenario/bootable.rb
@@ -23,7 +23,7 @@ module QA
 
           arguments.parse!(argv)
 
-          self.perform(Runtime::Scenario.attributes, *arguments.default_argv)
+          self.perform(Runtime::Scenario.attributes, *argv)
         end
 
         private
@@ -33,7 +33,13 @@ module QA
         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?
diff --git a/qa/qa/scenario/shared_attributes.rb b/qa/qa/scenario/shared_attributes.rb
new file mode 100644
index 00000000000..40d5c6b1ff1
--- /dev/null
+++ b/qa/qa/scenario/shared_attributes.rb
@@ -0,0 +1,12 @@
+# 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
diff --git a/qa/qa/scenario/template.rb b/qa/qa/scenario/template.rb
index cb1a1de6b9a..b8ea26e805e 100644
--- a/qa/qa/scenario/template.rb
+++ b/qa/qa/scenario/template.rb
@@ -18,19 +18,44 @@ module QA
         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
diff --git a/qa/qa/scenario/test/instance/all.rb b/qa/qa/scenario/test/instance/all.rb
index a07c26431bd..168ac4c09a1 100644
--- a/qa/qa/scenario/test/instance/all.rb
+++ b/qa/qa/scenario/test/instance/all.rb
@@ -8,6 +8,7 @@ module QA
       module Instance
         class All < Template
           include Bootable
+          include SharedAttributes
         end
       end
     end
diff --git a/qa/qa/scenario/test/instance/smoke.rb b/qa/qa/scenario/test/instance/smoke.rb
index a7d2cb27f27..43f0623483e 100644
--- a/qa/qa/scenario/test/instance/smoke.rb
+++ b/qa/qa/scenario/test/instance/smoke.rb
@@ -8,6 +8,7 @@ module QA
         #
         class Smoke < Template
           include Bootable
+          include SharedAttributes
 
           tags :smoke
         end
diff --git a/qa/qa/scenario/test/integration/mattermost.rb b/qa/qa/scenario/test/integration/mattermost.rb
index ece6fba75c9..f5072ee227c 100644
--- a/qa/qa/scenario/test/integration/mattermost.rb
+++ b/qa/qa/scenario/test/integration/mattermost.rb
@@ -9,10 +9,13 @@ module QA
         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
diff --git a/qa/qa/support/api.rb b/qa/qa/support/api.rb
index 229bfb44fa5..31cff5a241c 100644
--- a/qa/qa/support/api.rb
+++ b/qa/qa/support/api.rb
@@ -1,6 +1,9 @@
 module QA
   module Support
     module Api
+      HTTP_STATUS_OK = 200
+      HTTP_STATUS_CREATED = 201
+
       def post(url, payload)
         RestClient::Request.execute(
           method: :post,