add optional sidekiq for background jobs

Gemfile

@@ -27,6 +27,7 @@ gem 'rails-i18n'
 gem 'rollbar', require: ENV.key?('ROLLBAR_ACCESS_TOKEN')
 gem 'ruby-vips'
 gem 'shakapacker'
+gem 'sidekiq', require: ENV.key?('REDIS_URL')
 gem 'sqlite3', require: false
 gem 'strip_attributes'
 gem 'turbo-rails'

Gemfile.lock

@@ -388,6 +388,8 @@ GEM
       zeitwerk (~> 2.5)
     rainbow (3.1.1)
     rake (13.0.6)
+    redis-client (0.14.1)
+      connection_pool
     regexp_parser (2.8.1)
     reline (0.3.5)
       io-console (~> 0.5)
@@ -458,6 +460,11 @@ GEM
       rack-proxy (>= 0.6.1)
       railties (>= 5.2)
       semantic_range (>= 2.3.0)
+    sidekiq (7.1.2)
+      concurrent-ruby (< 2)
+      connection_pool (>= 2.3.0)
+      rack (>= 2.2.4)
+      redis-client (>= 0.14.0)
     signet (0.17.0)
       addressable (~> 2.8)
       faraday (>= 0.17.5, < 3.a)
@@ -554,6 +561,7 @@ DEPENDENCIES
   rubocop-rspec
   ruby-vips
   shakapacker
+  sidekiq
   simplecov
   sqlite3
   strip_attributes

config/environments/development.rb

@@ -45,6 +45,8 @@ Rails.application.configure do
     config.cache_store = :null_store
   end
 
+  config.active_job.queue_adapter = :sidekiq if defined?(Sidekiq)
+
   # Store uploaded files on the local file system (see config/storage.yml for options).
   config.active_storage.service = :disk
   config.active_storage.resolve_model_to_route = :rails_storage_proxy

config/environments/production.rb

@@ -25,6 +25,8 @@ Rails.application.configure do
   config.action_controller.perform_caching = true
   config.active_record.sqlite3_production_warning = false
 
+  config.active_job.queue_adapter = :sidekiq if defined?(Sidekiq)
+
   # Ensures that a master key has been made available in either ENV["RAILS_MASTER_KEY"]
   # or in config/master.key. This key is used to decrypt credentials (and other encrypted files).
   # config.require_master_key = true

config/initializers/sidekiq.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+if defined?(Sidekiq)
+  require 'sidekiq/web'
+
+  Sidekiq::Web.use(Rack::Auth::Basic) do |_, password|
+    next true if Rails.env.development?
+
+    ActiveSupport::SecurityUtils.secure_compare(
+      Digest::SHA256.hexdigest(password),
+      Digest::SHA256.hexdigest(ENV.fetch('SIDEKIQ_BASIC_AUTH_PASSWORD'))
+    )
+  end
+
+  Sidekiq.strict_args!
+end

config/routes.rb

@@ -2,6 +2,7 @@
 
 Rails.application.routes.draw do
   mount LetterOpenerWeb::Engine, at: '/letter_opener' if Rails.env.development?
+  mount Sidekiq::Web => '/sidekiq' if defined?(Sidekiq)
 
   root 'dashboard#index'
 

config/sidekiq.yml

@@ -0,0 +1,6 @@
+queues:
+  - [default, 1]
+  - [mailers, 1]
+
+production:
+  :concurrency: 15