chore(rails): migrate core settings to Rails credentials

- migrate db, recaptcha, redis, smtp credentials
- migrate cache_store from unmaintained redis_store to redis_cache_store

Author: adi-herwana-nus

config/cable.yml

@@ -8,5 +8,5 @@ test:
 
 production:
   adapter: redis
-  url: <%= ENV.fetch("REDIS_URL") { "redis://localhost:6379/1" } %>
+  url: redis://:<%= Rails.application.credentials.dig(:redis, :password) %>@<%= ENV['REDIS_HOST'] %>:6379
   channel_prefix: application_production

config/database.yml

@@ -6,6 +6,7 @@ default: &default
 development:
   <<: *default
   database: coursemology
+  host: localhost
 
 # Warning: The database defined as "test" will be erased and
 # re-generated from your development database when you run "rake".
@@ -17,3 +18,15 @@ test:
 production:
   <<: *default
   database: coursemology
+  host: <%= ENV["DB_HOST"] %>
+  username: <%= Rails.application.credentials.dig(:production_database, :username) %>
+  password: <%= Rails.application.credentials.dig(:production_database, :password) %>
+  pool: <%= ENV["RAILS_MAX_THREADS"] || 5 %>
+  port: <%= ENV["DB_PORT"] || 5432 %>
+
+maintenance:
+  <<: *default
+  database: coursemology
+  host: <%= ENV["DB_HOST"] %>
+  username: <%= Rails.application.credentials.dig(:maintenance_database, :username) %>
+  password: <%= Rails.application.credentials.dig(:maintenance_database, :password) %>

config/environments/production.rb

@@ -26,7 +26,7 @@
   # NGINX, varnish or squid.
   # config.action_dispatch.rack_cache = true
   # We will configure the host from the environment.
-  config.action_mailer.default_url_options = { host: ENV.fetch('RAILS_HOSTNAME') }
+  config.action_mailer.default_url_options = { host: ENV['RAILS_HOSTNAME'] }
 
   # 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).
@@ -134,7 +134,7 @@
   # config.active_record.database_resolver = ActiveRecord::Middleware::DatabaseSelector::Resolver
   # config.active_record.database_resolver_context = ActiveRecord::Middleware::DatabaseSelector::Resolver::Session
   #
-  config.x.default_host = ENV.fetch('RAILS_HOSTNAME')
+  config.x.default_host = ENV['RAILS_HOSTNAME']
   config.active_job.queue_adapter = :sidekiq
 
   # Rails 6.0.5.1 security patch

config/environments/test.rb

@@ -27,7 +27,6 @@
   # Show full error reports and disable caching.
   config.consider_all_requests_local       = true
   config.action_controller.perform_caching = false
-  config.cache_store = :null_store
 
   # Raise exceptions instead of rendering exception templates.
   config.action_dispatch.show_exceptions = false

config/initializers/action_cable.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+Rails.application.configure do
+  config.action_cable.mount_path = '/cable'
+  # config.action_cable.url = 'ws://example.com:28080'
+  config.action_cable.allowed_request_origins = [/^(https?:\/\/)?([^.\/]+\.)?#{ENV['RAILS_HOSTNAME']}/]
+end

config/initializers/cache_store.rb

@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+Rails.application.configure do
+  config.cache_store = :redis_cache_store, {
+    host: ENV['REDIS_HOST'],
+    port: 6379,
+    db: 0,
+    password: Rails.application.credentials.dig(:redis, :password),
+    namespace: 'cache',
+    expires_in: 90.minutes
+  }
+
+  config.session_store :redis_store,
+                       servers: {
+                         host: ENV['REDIS_HOST'],
+                         port: 6379,
+                         db: 0,
+                         password: Rails.application.credentials.dig(:redis, :password),
+                         namespace: 'session'
+                       },
+                       expire_after: 240.minutes
+end

config/initializers/mini_profiler.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+# Enables rack_mini_profiler for all requests in production
+# For use in our own staging environment, where RAILS_ENV=production
+
+Rails.application.config.after_initialize do
+  ApplicationController.class_eval do
+    before_action :enable_miniprofiler
+
+    def enable_miniprofiler
+      return unless current_user&.administrator?
+
+      Rack::MiniProfiler.authorize_request
+    end
+  end
+end

config/initializers/rack_mini_profiler.rb

@@ -1,3 +1,9 @@
 # frozen_string_literal: true
-# TODO: Remove this once fully SPA
-Rack::MiniProfiler.config.position = 'top-right'
+# Set Redis storage for Rack Mini Profiler.
+# https://github.com/MiniProfiler/rack-mini-profiler#storage
+
+Rack::MiniProfiler.config.storage_options = {
+  host: ENV['REDIS_HOST'],
+  password: Rails.application.credentials.dig(:redis, :password)
+}
+Rack::MiniProfiler.config.storage = Rack::MiniProfiler::RedisStore

config/initializers/recaptcha.rb

@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 Recaptcha.configure do |config|
   if Rails.env.production?
-    config.site_key = ENV['GOOGLE_RECAPTCHA_SITE_KEY']
-    config.secret_key = ENV['GOOGLE_RECAPTCHA_SECRET_KEY']
+    config.site_key = Rails.application.credentials.dig(:google_recaptcha, :site_key)
+    config.secret_key = Rails.application.credentials.dig(:google_recaptcha, :secret_key)
   else
     # The following keys are for test and development environments only.
     # You will always get No CAPTCHA and all verification requests will pass.

config/initializers/redis.rb

@@ -2,6 +2,6 @@
 
 redis_host = ENV['REDIS_HOST']
 redis_port = 6379
-redis_password = ENV['REDIS_PASS']
+redis_password = Rails.application.credentials.dig(:redis, :password)
 
 REDIS = Redis.new(host: redis_host, port: redis_port, password: redis_password, db: 0)