Use the configured redis DB in specs that run workhorse

Rails configures the redis DB in the URL, while workhorse uses a
separate config entry. Handle this in the specs in preparation for
running them against redis db 1 instead of redis db 0

lib/gitlab/redis/wrapper.rb

@@ -8,6 +8,10 @@ require 'active_support/core_ext/hash/keys'
 require 'active_support/core_ext/module/delegation'
 require 'active_support/core_ext/string/inflections'
 
+# Explicitly load Redis::Store::Factory so we can read Redis configuration in
+# TestEnv
+require 'redis/store/factory'
+
 module Gitlab
   module Redis
     class Wrapper

lib/gitlab/setup_helper.rb

@@ -32,7 +32,7 @@ module Gitlab
       extend Gitlab::SetupHelper
       class << self
         def configuration_toml(dir, _, _)
-          config = { redis: { URL: redis_url } }
+          config = { redis: { URL: redis_url, DB: redis_db } }
 
           TomlRB.dump(config)
         end
@@ -41,6 +41,10 @@ module Gitlab
           Gitlab::Redis::SharedState.url
         end
 
+        def redis_db
+          Gitlab::Redis::SharedState.params.fetch(:db, 0)
+        end
+
         def get_config_path(dir, _)
           File.join(dir, 'config_path')
         end

spec/lib/gitlab/setup_helper/workhorse_spec.rb

@@ -22,4 +22,28 @@ RSpec.describe Gitlab::SetupHelper::Workhorse do
       end
     end
   end
+
+  describe '.redis_url' do
+    it 'matches the SharedState URL' do
+      expect(Gitlab::Redis::SharedState).to receive(:url).and_return('foo')
+
+      expect(described_class.redis_url).to eq('foo')
+    end
+  end
+
+  describe '.redis_db' do
+    subject { described_class.redis_db }
+
+    it 'matches the SharedState DB' do
+      expect(Gitlab::Redis::SharedState).to receive(:params).and_return(db: 1)
+
+      is_expected.to eq(1)
+    end
+
+    it 'defaults to 0 if unspecified' do
+      expect(Gitlab::Redis::SharedState).to receive(:params).and_return({})
+
+      is_expected.to eq(0)
+    end
+  end
 end

spec/support/helpers/test_env.rb

@@ -263,8 +263,13 @@ module TestEnv
 
   # Feature specs are run through Workhorse
   def setup_workhorse
+    # Always rebuild the config file
+    if skip_compile_workhorse?
+      Gitlab::SetupHelper::Workhorse.create_configuration(workhorse_dir, nil)
+      return
+    end
+
     start = Time.now
-    return if skip_compile_workhorse?
 
     FileUtils.rm_rf(workhorse_dir)
     Gitlab::SetupHelper::Workhorse.compile_into(workhorse_dir)
@@ -305,12 +310,6 @@ module TestEnv
 
     config_path = Gitlab::SetupHelper::Workhorse.get_config_path(workhorse_dir, {})
 
-    # This should be set up in setup_workhorse, but since
-    # component_needs_update? only checks that versions are consistent,
-    # we need to ensure the config file exists. This line can be removed
-    # later after a new Workhorse version is updated.
-    Gitlab::SetupHelper::Workhorse.create_configuration(workhorse_dir, nil) unless File.exist?(config_path)
-
     workhorse_pid = spawn(
       { 'PATH' => "#{ENV['PATH']}:#{workhorse_dir}" },
       File.join(workhorse_dir, 'gitlab-workhorse'),