Add a Redis environment variable for sidekiq (#16188)

config/initializers/sidekiq.rb

@@ -1,14 +1,7 @@
 # frozen_string_literal: true
 
-namespace    = ENV.fetch('REDIS_NAMESPACE') { nil }
-redis_params = { url: ENV['REDIS_URL'], driver: :hiredis }
-
-if namespace
-  redis_params[:namespace] = namespace
-end
-
 Sidekiq.configure_server do |config|
-  config.redis = redis_params
+  config.redis = REDIS_SIDEKIQ_PARAMS
 
   config.server_middleware do |chain|
     chain.add SidekiqErrorHandler
@@ -26,7 +19,7 @@ Sidekiq.configure_server do |config|
 end
 
 Sidekiq.configure_client do |config|
-  config.redis = redis_params
+  config.redis = REDIS_SIDEKIQ_PARAMS
 
   config.client_middleware do |chain|
     chain.add SidekiqUniqueJobs::Middleware::Client

lib/mastodon/redis_config.rb

@@ -22,9 +22,11 @@ end
 
 setup_redis_env_url
 setup_redis_env_url(:cache, false)
+setup_redis_env_url(:sidekiq, false)
 
 namespace         = ENV.fetch('REDIS_NAMESPACE', nil)
 cache_namespace   = namespace ? namespace + '_cache' : 'cache'
+sidekiq_namespace = namespace
 
 REDIS_CACHE_PARAMS = {
   driver: :hiredis,
@@ -32,3 +34,9 @@ REDIS_CACHE_PARAMS = {
   expires_in: 10.minutes,
   namespace: cache_namespace,
 }.freeze
+
+REDIS_SIDEKIQ_PARAMS = {
+  driver: :hiredis,
+  url: ENV['SIDEKIQ_REDIS_URL'],
+  namespace: sidekiq_namespace,
+}.freeze