Upgrade to Rails 5.0.0.1

config/environments/production.rb

@@ -14,15 +14,9 @@ Rails.application.configure do
   config.consider_all_requests_local       = false
   config.action_controller.perform_caching = true
 
-  # Enable Rack::Cache to put a simple HTTP cache in front of your application
-  # Add `rack-cache` to your Gemfile before enabling this.
-  # For large-scale production use, consider using a caching reverse proxy like
-  # NGINX, varnish or squid.
-  # config.action_dispatch.rack_cache = true
-
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.serve_static_files = true
+  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
 
   # Compress JavaScripts and CSS.
   config.assets.js_compressor = :uglifier
@@ -31,10 +25,6 @@ Rails.application.configure do
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
-  # yet still be able to expire them through the digest params.
-  config.assets.digest = true
-
   # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
 
   # Specifies the header that your server uses for sending files.
@@ -49,7 +39,7 @@ Rails.application.configure do
   config.log_level = :debug
 
   # Prepend all log lines with the following tags.
-  # config.log_tags = [ :subdomain, :uuid ]
+  config.log_tags = [ :request_id ]
 
   # Use a different logger for distributed setups.
   # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)
@@ -77,6 +67,8 @@ Rails.application.configure do
   # Do not dump schema after migrations.
   config.active_record.dump_schema_after_migration = false
 
+  config.action_mailer.perform_caching = false
+
   # E-mails
   config.action_mailer.smtp_settings = {
     :port           => ENV['SMTP_PORT'],