Add option to use native Ruby driver for Redis (#30717)

app/lib/redis_configuration.rb

@@ -42,9 +42,13 @@ class RedisConfiguration
     ENV['REDIS_URL']
   end
 
+  def redis_driver
+    ENV.fetch('REDIS_DRIVER', 'hiredis') == 'ruby' ? :ruby : :hiredis
+  end
+
   private
 
   def raw_connection
-    Redis.new(url: url, driver: :hiredis)
+    Redis.new(url: url, driver: redis_driver)
   end
 end

lib/mastodon/redis_config.rb

@@ -30,8 +30,10 @@ namespace         = ENV.fetch('REDIS_NAMESPACE', nil)
 cache_namespace   = namespace ? "#{namespace}_cache" : 'cache'
 sidekiq_namespace = namespace
 
+redis_driver = ENV.fetch('REDIS_DRIVER', 'hiredis') == 'ruby' ? :ruby : :hiredis
+
 REDIS_CACHE_PARAMS = {
-  driver: :hiredis,
+  driver: redis_driver,
   url: ENV['CACHE_REDIS_URL'],
   expires_in: 10.minutes,
   namespace: "#{cache_namespace}:7.1",
@@ -43,7 +45,7 @@ REDIS_CACHE_PARAMS = {
 }.freeze
 
 REDIS_SIDEKIQ_PARAMS = {
-  driver: :hiredis,
+  driver: redis_driver,
   url: ENV['SIDEKIQ_REDIS_URL'],
   namespace: sidekiq_namespace,
 }.freeze