Always enable the request store in Sidekiq

This removes the possibility to disable the request store in
Sidekiq. The feature was enabled for a few months, and we don't know
of anybody that actually used this ENV-flag.

changelogs/unreleased/bvl-remove-sidekiq-request-store-env.yml

+---
+title: Remove the SIDEKIQ_REQUEST_STORE configuration
+merge_request: 29955
+author:
+type: other

config/initializers/sidekiq.rb

@@ -33,7 +33,6 @@ enable_json_logs = Gitlab.config.sidekiq.log_format == 'json'
 enable_sidekiq_memory_killer = ENV['SIDEKIQ_MEMORY_KILLER_MAX_RSS'].to_i.nonzero?
 use_sidekiq_daemon_memory_killer = ENV["SIDEKIQ_DAEMON_MEMORY_KILLER"].to_i.nonzero?
 use_sidekiq_legacy_memory_killer = !use_sidekiq_daemon_memory_killer
-use_request_store = ENV.fetch('SIDEKIQ_REQUEST_STORE', 1).to_i.nonzero?
 
 Sidekiq.configure_server do |config|
   if enable_json_logs
@@ -50,8 +49,7 @@ Sidekiq.configure_server do |config|
   config.server_middleware(&Gitlab::SidekiqMiddleware.server_configurator({
     metrics: Settings.monitoring.sidekiq_exporter,
     arguments_logger: ENV['SIDEKIQ_LOG_ARGUMENTS'] && !enable_json_logs,
-    memory_killer: enable_sidekiq_memory_killer && use_sidekiq_legacy_memory_killer,
-    request_store: use_request_store
+    memory_killer: enable_sidekiq_memory_killer && use_sidekiq_legacy_memory_killer
   }))
 
   config.client_middleware(&Gitlab::SidekiqMiddleware.client_configurator)

lib/gitlab/sidekiq_middleware.rb

@@ -7,13 +7,13 @@ module Gitlab
     # The result of this method should be passed to
     # Sidekiq's `config.server_middleware` method
     # eg: `config.server_middleware(&Gitlab::SidekiqMiddleware.server_configurator)`
-    def self.server_configurator(metrics: true, arguments_logger: true, memory_killer: true, request_store: true)
+    def self.server_configurator(metrics: true, arguments_logger: true, memory_killer: true)
       lambda do |chain|
         chain.add ::Gitlab::SidekiqMiddleware::Monitor
         chain.add ::Gitlab::SidekiqMiddleware::ServerMetrics if metrics
         chain.add ::Gitlab::SidekiqMiddleware::ArgumentsLogger if arguments_logger
         chain.add ::Gitlab::SidekiqMiddleware::MemoryKiller if memory_killer
-        chain.add ::Gitlab::SidekiqMiddleware::RequestStoreMiddleware if request_store
+        chain.add ::Gitlab::SidekiqMiddleware::RequestStoreMiddleware
         chain.add ::Gitlab::SidekiqMiddleware::BatchLoader
         chain.add ::Labkit::Middleware::Sidekiq::Server
         chain.add ::Gitlab::SidekiqMiddleware::InstrumentationLogger

spec/lib/gitlab/sidekiq_middleware_spec.rb

@@ -32,8 +32,7 @@ describe Gitlab::SidekiqMiddleware do
         described_class.server_configurator(
           metrics: metrics,
           arguments_logger: arguments_logger,
-          memory_killer: memory_killer,
-          request_store: request_store
+          memory_killer: memory_killer
         ).call(chain)
 
         example.run
@@ -77,13 +76,11 @@ describe Gitlab::SidekiqMiddleware do
       let(:metrics) { false }
       let(:arguments_logger) { false }
       let(:memory_killer) { false }
-      let(:request_store) { false }
       let(:disabled_sidekiq_middlewares) do
         [
           Gitlab::SidekiqMiddleware::ServerMetrics,
           Gitlab::SidekiqMiddleware::ArgumentsLogger,
-          Gitlab::SidekiqMiddleware::MemoryKiller,
-          Gitlab::SidekiqMiddleware::RequestStoreMiddleware
+          Gitlab::SidekiqMiddleware::MemoryKiller
         ]
       end
 
@@ -94,7 +91,6 @@ describe Gitlab::SidekiqMiddleware do
       let(:metrics) { true }
       let(:arguments_logger) { true }
       let(:memory_killer) { true }
-      let(:request_store) { true }
       let(:disabled_sidekiq_middlewares) { [] }
 
       it_behaves_like "a server middleware chain"

spec/spec_helper.rb

@@ -305,10 +305,7 @@ RSpec.configure do |config|
       Gitlab::SidekiqMiddleware.server_configurator(
         metrics: false, # The metrics don't go anywhere in tests
         arguments_logger: false, # We're not logging the regular messages for inline jobs
-        memory_killer: false, # This is not a thing we want to do inline in tests
-        # Don't enable this if the request store is active in the spec itself
-        # This needs to run within the `request_store` around block defined above
-        request_store: !RequestStore.active?
+        memory_killer: false # This is not a thing we want to do inline in tests
       ).call(chain)
       chain.add DisableQueryLimit