class Rails::Application
-
Run
config.after_initialize
callbacks.
10. Runconfig.before_eager_load
andeager_load!
ifeager_load
istrue
.
9. Build the middleware stack and runto_prepare
callbacks.
8. CustomRailtie#initializers
added by railties, engines, and applications are executed.
One by one, each engine sets up its load paths and routes, and runs itsconfig/initializers/*
files.
7. RunRailtie#initializer
defined by railties, engines, and application.
6. Runconfig.before_initialize
callbacks.
5. Loadconfig/environments/ENV.rb
.
4. Runconfig.before_configuration
callbacks.
3. DefineRails.application
asclass MyApp::Application < Rails::Application
.
2.require
railties and engines.
1.require "config/boot.rb"
to set up load paths.
the booting process goes like this:
process. From the moment you requireconfig/application.rb
in your app,
The application is also responsible for setting up and executing the booting
== Booting process
The Application is also responsible for building the middleware stack.
== Middlewares
whenever the files change in development.
The application object is also responsible for holding the routes and reloading routes
== Routes
Check Rails::Application::Configuration to see them all.logger
, and so forth.cache_classes
,consider_all_requests_local
,filter_parameters
,
the application object has several specific configurations, for example
Besides providing the same configuration as Rails::Engine and Rails::Railtie,
== Configuration
are executed (check Rails::Application::Finisher).
Rails::Application::Bootstrap) and finishing initializers, after all the others
initializers. It also executes some bootstrap initializers (check
Rails::Application is responsible for executing all railties and engines
== Initialization
An Engine with the responsibility of coordinating the whole boot process.
def self.add_lib_to_load_path!(root) # :nodoc:
you need to load files in lib/ during the application configuration as well.
Rails application, you will need to add lib to $LOAD_PATH on your own in case
are changing config.root inside your application definition or having a custom
Notice this method takes into consideration the default root path. So if you
end
config.i18n.backend = MyBackend
require "my_backend" # in lib/my_backend
class MyApplication < Rails::Application
configuration.
allowing the developer to load classes in lib and use them during application
This method is called just after an application inherits from Rails::Application,
def self.add_lib_to_load_path!(root) # :nodoc: path = File.join root, "lib" if File.exist?(path) && !$LOAD_PATH.include?(path) $LOAD_PATH.unshift(path) end end
def build_middleware
def build_middleware config.app_middleware + super end
def build_request(env)
def build_request(env) req = super env["ORIGINAL_FULLPATH"] = req.fullpath env["ORIGINAL_SCRIPT_NAME"] = req.script_name req end
def coerce_same_site_protection(protection)
def coerce_same_site_protection(protection) protection.respond_to?(:call) ? protection : proc { protection } end
def config # :nodoc:
def config # :nodoc: @config ||= Application::Configuration.new(self.class.find_root(self.class.called_from)) end
def config_for(name, env: Rails.env)
Rails.application.config_for(:example)[:foo][:bar]
# development environment
qux: 2
bar:
foo:
development:
baz: 1
bar:
foo:
shared:
# config/example.yml
# merged with the environment configuration
# You can also store configurations in a shared section which will be
end
config.middleware.use ExceptionNotifier, config_for(:exception_notification)
Rails.application.configure do
# config/environments/production.rb
namespace: my_app_development
url: http://localhost:3001
development:
namespace: my_app_production
url: http://127.0.0.1:8080
production:
# config/exception_notification.yml:
Examples:
Convenience for loading config/foo.yml for the current Rails env.
def config_for(name, env: Rails.env) yaml = name.is_a?(Pathname) ? name : Pathname.new("#{paths["config"].existent.first}/#{name}.yml") if yaml.exist? require "erb" all_configs = ActiveSupport::ConfigurationFile.parse(yaml).deep_symbolize_keys config, shared = all_configs[env.to_sym], all_configs[:shared] if shared config = {} if config.nil? && shared.is_a?(Hash) if config.is_a?(Hash) && shared.is_a?(Hash) config = shared.deep_merge(config) elsif config.nil? config = shared end end if config.is_a?(Hash) config = ActiveSupport::OrderedOptions.new.update(config) end config else raise "Could not load configuration. No such file - #{yaml}" end end
def console(&blk)
Sends any console called in the instance of a new application up
def console(&blk) self.class.console(&blk) end
def create(initial_variable_values = {}, &block)
def create(initial_variable_values = {}, &block) new(initial_variable_values, &block).run_load_hooks! end
def credentials
config/credentials/#{environment}.key for the current
+config.credentials.key_path+ will point to either
or from the file specified by +config.credentials.key_path+. By default,
The encryption key is taken from either ENV["RAILS_MASTER_KEY"],
does not exist.
+production+ environment), or +config/credentials.yml.enc+ if that file
environment (for example, +config/credentials/production.yml.enc+ for the
config/credentials/#{environment}.yml.enc for the current
By default, +config.credentials.content_path+ will point to either
credentials file specified by +config.credentials.content_path+.
Returns an ActiveSupport::EncryptedConfiguration instance for the
def credentials @credentials ||= encrypted(config.credentials.content_path, key_path: config.credentials.key_path) end
def default_middleware_stack # :nodoc:
def default_middleware_stack # :nodoc: default_stack = DefaultMiddlewareStack.new(self, config, paths) default_stack.build_stack end
def eager_load!
def eager_load! Rails.autoloaders.each(&:eager_load) end
def encrypted(path, key_path: "config/master.key", env_key: "RAILS_MASTER_KEY")
command. (See the output of bin/rails encrypted:edit --help for
Encrypted files can be edited with the bin/rails encrypted:edit
# => 123
my_config.foo.bar
# => "foo:\n bar: 123\n"
my_config.read
my_config = Rails.application.encrypted("config/my_config.enc")
ENV["RAILS_MASTER_KEY"], or from the +config/master.key+ file.
file. By default, the encryption key is taken from either
Returns an ActiveSupport::EncryptedConfiguration instance for an encrypted
def encrypted(path, key_path: "config/master.key", env_key: "RAILS_MASTER_KEY") ActiveSupport::EncryptedConfiguration.new( config_path: Rails.root.join(path), key_path: Rails.root.join(key_path), env_key: env_key, raise_if_missing_key: config.require_master_key ) end
def env_config
Stores some of the Rails initial environment parameters which
def env_config @app_env_config ||= super.merge( "action_dispatch.parameter_filter" => config.filter_parameters, "action_dispatch.redirect_filter" => config.filter_redirect, "action_dispatch.secret_key_base" => secret_key_base, "action_dispatch.show_exceptions" => config.action_dispatch.show_exceptions, "action_dispatch.show_detailed_exceptions" => config.consider_all_requests_local, "action_dispatch.log_rescued_responses" => config.action_dispatch.log_rescued_responses, "action_dispatch.logger" => Rails.logger, "action_dispatch.backtrace_cleaner" => Rails.backtrace_cleaner, "action_dispatch.key_generator" => key_generator, "action_dispatch.http_auth_salt" => config.action_dispatch.http_auth_salt, "action_dispatch.signed_cookie_salt" => config.action_dispatch.signed_cookie_salt, "action_dispatch.encrypted_cookie_salt" => config.action_dispatch.encrypted_cookie_salt, "action_dispatch.encrypted_signed_cookie_salt" => config.action_dispatch.encrypted_signed_cookie_salt, "action_dispatch.authenticated_encrypted_cookie_salt" => config.action_dispatch.authenticated_encrypted_cookie_salt, "action_dispatch.use_authenticated_cookie_encryption" => config.action_dispatch.use_authenticated_cookie_encryption, "action_dispatch.encrypted_cookie_cipher" => config.action_dispatch.encrypted_cookie_cipher, "action_dispatch.signed_cookie_digest" => config.action_dispatch.signed_cookie_digest, "action_dispatch.cookies_serializer" => config.action_dispatch.cookies_serializer, "action_dispatch.cookies_digest" => config.action_dispatch.cookies_digest, "action_dispatch.cookies_rotations" => config.action_dispatch.cookies_rotations, "action_dispatch.cookies_same_site_protection" => coerce_same_site_protection(config.action_dispatch.cookies_same_site_protection), "action_dispatch.use_cookies_with_metadata" => config.action_dispatch.use_cookies_with_metadata, "action_dispatch.content_security_policy" => config.content_security_policy, "action_dispatch.content_security_policy_report_only" => config.content_security_policy_report_only, "action_dispatch.content_security_policy_nonce_generator" => config.content_security_policy_nonce_generator, "action_dispatch.content_security_policy_nonce_directives" => config.content_security_policy_nonce_directives, "action_dispatch.permissions_policy" => config.permissions_policy, ) end
def find_root(from)
def find_root(from) find_root_with_flag "config.ru", from, Dir.pwd end
def generate_development_secret
def generate_development_secret if secrets.secret_key_base.nil? key_file = Rails.root.join("tmp/development_secret.txt") if !File.exist?(key_file) random_key = SecureRandom.hex(64) FileUtils.mkdir_p(key_file.dirname) File.binwrite(key_file, random_key) end secrets.secret_key_base = File.binread(key_file) end secrets.secret_key_base end
def generators(&blk)
Sends any generators called in the instance of a new application up
def generators(&blk) self.class.generators(&blk) end
def helpers_paths # :nodoc:
def helpers_paths # :nodoc: config.helpers_paths end
def inherited(base)
def inherited(base) super Rails.app_class = base add_lib_to_load_path!(find_root(base.called_from)) ActiveSupport.run_load_hooks(:before_configuration, base) end
def initialize(initial_variable_values = {}, &block)
def initialize(initial_variable_values = {}, &block) super() @initialized = false @reloaders = [] @routes_reloader = nil @app_env_config = nil @ordered_railties = nil @railties = nil @message_verifiers = {} @ran_load_hooks = false @executor = Class.new(ActiveSupport::Executor) @reloader = Class.new(ActiveSupport::Reloader) @reloader.executor = @executor @autoloaders = Rails::Autoloaders.new # are these actually used? @initial_variable_values = initial_variable_values @block = block end
def initialize!(group = :default) # :nodoc:
group is :default
Initialize the application passing the given group. By default, the
def initialize!(group = :default) # :nodoc: raise "Application has been already initialized." if @initialized run_initializers(group, self) @initialized = true self end
def initialized?
def initialized? @initialized end
def initializer(name, opts = {}, &block)
Rails::Initializable module. Each Rails::Application class has its own
Sends the initializers to the +initializer+ method defined in the
def initializer(name, opts = {}, &block) self.class.initializer(name, opts, &block) end
def initializers # :nodoc:
def initializers # :nodoc: Bootstrap.initializers_for(self) + railties_initializers(super) + Finisher.initializers_for(self) end
def instance
def instance super.run_load_hooks! end
def isolate_namespace(mod)
def isolate_namespace(mod) self.class.isolate_namespace(mod) end
def key_generator
def key_generator # number of iterations selected based on consultation with the google security # team. Details at https://github.com/rails/rails/pull/6952#issuecomment-7661220 @caching_key_generator ||= ActiveSupport::CachingKeyGenerator.new( ActiveSupport::KeyGenerator.new(secret_key_base, iterations: 1000) ) end
def message_verifier(verifier_name)
# => 'my sensible data'
Rails.application.message_verifier('sensitive_data').verify(message)
message = Rails.application.message_verifier('sensitive_data').generate('my sensible data')
==== Examples
* +verifier_name+ - the name of the message verifier.
==== Parameters
verifiers passing the +verifier_name+ argument.
It is recommended not to use the same verifier for different things, so you can get different
This verifier can be used to generate and verify signed messages in the application.
Returns a message verifier object.
def message_verifier(verifier_name) @message_verifiers[verifier_name] ||= begin secret = key_generator.generate_key(verifier_name.to_s) ActiveSupport::MessageVerifier.new(secret) end end
def migration_railties # :nodoc:
+railties_order+.
copying migrations from railties ; we need them in the order given by
While running initializers we need engines in reverse order here when
and the order specified by the +railties_order+ config.
Return an array of railties respecting the order they're loaded
def migration_railties # :nodoc: ordered_railties.flatten - [self] end
def ordered_railties # :nodoc:
Returns the ordered railties for this application considering railties_order.
def ordered_railties # :nodoc: @ordered_railties ||= begin order = config.railties_order.map do |railtie| if railtie == :main_app self elsif railtie.respond_to?(:instance) railtie.instance else railtie end end all = (railties - order) all.push(self) unless (all + order).include?(self) order.push(:all) unless order.include?(:all) index = order.index(:all) order[index] = all order end end
def railties_initializers(current) # :nodoc:
def railties_initializers(current) # :nodoc: initializers = [] ordered_railties.reverse.flatten.each do |r| if r == self initializers += current else initializers += r.initializers end end initializers end
def rake_tasks(&block)
If you try to define a set of Rake tasks on the instance, these will get
def rake_tasks(&block) self.class.rake_tasks(&block) end
def reload_routes!
def reload_routes! routes_reloader.reload! end
def require_environment! # :nodoc:
def require_environment! # :nodoc: environment = paths["config/environment"].existent.first require environment if environment end
def routes_reloader # :nodoc:
def routes_reloader # :nodoc: @routes_reloader ||= RoutesReloader.new end
def run_console_blocks(app) # :nodoc:
def run_console_blocks(app) # :nodoc: railties.each { |r| r.run_console_blocks(app) } super end
def run_generators_blocks(app) # :nodoc:
def run_generators_blocks(app) # :nodoc: railties.each { |r| r.run_generators_blocks(app) } super end
def run_load_hooks! # :nodoc:
def run_load_hooks! # :nodoc: return self if @ran_load_hooks @ran_load_hooks = true @initial_variable_values.each do |variable_name, value| if INITIAL_VARIABLES.include?(variable_name) instance_variable_set("@#{variable_name}", value) end end instance_eval(&@block) if @block self end
def run_runner_blocks(app) # :nodoc:
def run_runner_blocks(app) # :nodoc: railties.each { |r| r.run_runner_blocks(app) } super end
def run_server_blocks(app) # :nodoc:
def run_server_blocks(app) # :nodoc: railties.each { |r| r.run_server_blocks(app) } super end
def run_tasks_blocks(app) # :nodoc:
def run_tasks_blocks(app) # :nodoc: railties.each { |r| r.run_tasks_blocks(app) } super load "rails/tasks.rb" task :environment do ActiveSupport.on_load(:before_initialize) { config.eager_load = config.rake_eager_load } require_environment! end end
def runner(&blk)
Sends any runner called in the instance of a new application up
def runner(&blk) self.class.runner(&blk) end
def secret_key_base
then +credentials.secret_key_base+, and finally +secrets.secret_key_base+. For most applications,
In all other environments, we look for it first in ENV["SECRET_KEY_BASE"],
temporary file in tmp/development_secret.txt.
In development and test, this is randomly generated and stored in a
including the ones that sign and encrypt cookies.
is used to create all ActiveSupport::MessageVerifier and ActiveSupport::MessageEncryptor instances,
The secret_key_base is used as the input secret to the application's key generator, which in turn
def secret_key_base if Rails.env.development? || Rails.env.test? secrets.secret_key_base ||= generate_development_secret else validate_secret_key_base( ENV["SECRET_KEY_BASE"] || credentials.secret_key_base || secrets.secret_key_base ) end end
def secrets
def secrets @secrets ||= begin secrets = ActiveSupport::OrderedOptions.new files = config.paths["config/secrets"].existent files = files.reject { |path| path.end_with?(".enc") } unless config.read_encrypted_secrets secrets.merge! Rails::Secrets.parse(files, env: Rails.env) # Fallback to config.secret_key_base if secrets.secret_key_base isn't set secrets.secret_key_base ||= config.secret_key_base secrets end end
def server(&blk)
Sends any server called in the instance of a new application up
def server(&blk) self.class.server(&blk) end
def to_app # :nodoc:
def to_app # :nodoc: self end
def validate_secret_key_base(secret_key_base)
def validate_secret_key_base(secret_key_base) if secret_key_base.is_a?(String) && secret_key_base.present? secret_key_base elsif secret_key_base raise ArgumentError, "`secret_key_base` for #{Rails.env} environment must be a type of String`" else raise ArgumentError, "Missing `secret_key_base` for '#{Rails.env}' environment, set this string with `bin/rails credentials:edit`" end end
def watchable_args # :nodoc:
API.
directories-extensions suitable for ActiveSupport::FileUpdateChecker
Returns an array of file paths appended with a hash of
def watchable_args # :nodoc: files, dirs = config.watchable_files.dup, config.watchable_dirs.dup ActiveSupport::Dependencies.autoload_paths.each do |path| File.file?(path) ? files << path.to_s : dirs[path.to_s] = [:rb] end [files, dirs] end