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Diffstat (limited to 'guides/source/configuring.md')
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1 files changed, 157 insertions, 58 deletions
diff --git a/guides/source/configuring.md b/guides/source/configuring.md index 43c2ac6827..e1c9fad232 100644 --- a/guides/source/configuring.md +++ b/guides/source/configuring.md @@ -1,4 +1,4 @@ -**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON https://guides.rubyonrails.org.** Configuring Rails Applications ============================== @@ -69,7 +69,7 @@ These configuration methods are to be called on a `Rails::Railtie` object, such * `config.beginning_of_week` sets the default beginning of week for the application. Accepts a valid week day symbol (e.g. `:monday`). -* `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, or an object that implements the cache API. Defaults to `:file_store`. +* `config.cache_store` configures which cache store to use for Rails caching. Options include one of the symbols `:memory_store`, `:file_store`, `:mem_cache_store`, `:null_store`, `:redis_cache_store`, or an object that implements the cache API. Defaults to `:file_store`. * `config.colorize_logging` specifies whether or not to use ANSI color codes when logging information. Defaults to `true`. @@ -86,6 +86,8 @@ application. Accepts a valid week day symbol (e.g. `:monday`). end ``` +* `config.disable_sandbox` controls whether or not someone can start a console in sandbox mode. This is helpful to avoid a long running session of sandbox console, that could lead a database server to run out of memory. Defaults to false. + * `config.eager_load` when `true`, eager loads all registered `config.eager_load_namespaces`. This includes your application, engines, Rails frameworks, and any other registered namespace. * `config.eager_load_namespaces` registers namespaces that are eager loaded when `config.eager_load` is `true`. All namespaces in the list must respond to the `eager_load!` method. @@ -104,9 +106,9 @@ application. Accepts a valid week day symbol (e.g. `:monday`). * `config.filter_parameters` used for filtering out the parameters that you don't want shown in the logs, such as passwords or credit card -numbers. By default, Rails filters out passwords by adding `Rails.application.config.filter_parameters += [:password]` in `config/initializers/filter_parameter_logging.rb`. Parameters filter works by partial matching regular expression. +numbers. It also filters out sensitive values of database columns when call `#inspect` on an Active Record object. By default, Rails filters out passwords by adding `Rails.application.config.filter_parameters += [:password]` in `config/initializers/filter_parameter_logging.rb`. Parameters filter works by partial matching regular expression. -* `config.force_ssl` forces all requests to be served over HTTPS by using the `ActionDispatch::SSL` middleware, and sets `config.action_mailer.default_url_options` to be `{ protocol: 'https' }`. This can be configured by setting `config.ssl_options` - see the [ActionDispatch::SSL documentation](http://api.rubyonrails.org/classes/ActionDispatch/SSL.html) for details. +* `config.force_ssl` forces all requests to be served over HTTPS by using the `ActionDispatch::SSL` middleware, and sets `config.action_mailer.default_url_options` to be `{ protocol: 'https' }`. This can be configured by setting `config.ssl_options` - see the [ActionDispatch::SSL documentation](https://api.rubyonrails.org/classes/ActionDispatch/SSL.html) for details. * `config.log_formatter` defines the formatter of the Rails logger. This option defaults to an instance of `ActiveSupport::Logger::SimpleFormatter` for all modes. If you are setting a value for `config.logger` you must manually pass the value of your formatter to your logger before it is wrapped in an `ActiveSupport::TaggedLogging` instance, Rails will not do it for you. @@ -119,12 +121,11 @@ defaults to `:debug` for all environments. The available log levels are: `:debug * `config.logger` is the logger that will be used for `Rails.logger` and any related Rails logging such as `ActiveRecord::Base.logger`. It defaults to an instance of `ActiveSupport::TaggedLogging` that wraps an instance of `ActiveSupport::Logger` which outputs a log to the `log/` directory. You can supply a custom logger, to get full compatibility you must follow these guidelines: * To support a formatter, you must manually assign a formatter from the `config.log_formatter` value to the logger. * To support tagged logs, the log instance must be wrapped with `ActiveSupport::TaggedLogging`. - * To support silencing, the logger must include `LoggerSilence` and `ActiveSupport::LoggerThreadSafeLevel` modules. The `ActiveSupport::Logger` class already includes these modules. + * To support silencing, the logger must include `ActiveSupport::LoggerSilence` module. The `ActiveSupport::Logger` class already includes these modules. ```ruby class MyLogger < ::Logger - include ActiveSupport::LoggerThreadSafeLevel - include LoggerSilence + include ActiveSupport::LoggerSilence end mylogger = MyLogger.new(STDOUT) @@ -136,6 +137,10 @@ defaults to `:debug` for all environments. The available log levels are: `:debug * `config.reload_classes_only_on_change` enables or disables reloading of classes only when tracked files change. By default tracks everything on autoload paths and is set to `true`. If `config.cache_classes` is `true`, this option is ignored. +* `config.credentials.content_path` configures lookup path for encrypted credentials. + +* `config.credentials.key_path` configures lookup path for encryption key. + * `secret_key_base` is used for specifying a key which allows sessions for the application to be verified against a known secure key to prevent tampering. Applications get a random generated key in test and development environments, other environments should set one in `config/credentials.yml.enc`. * `config.public_file_server.enabled` configures Rails to serve static files from the public directory. This option defaults to `true`, but in the production environment it is set to `false` because the server software (e.g. NGINX or Apache) used to run the application should serve static files instead. If you are running or testing your app in production mode using WEBrick (it is not recommended to use WEBrick in production) set the option to `true.` Otherwise, you won't be able to use page caching and request for files that exist under the public directory. @@ -201,8 +206,6 @@ The full set of methods that can be used in this block are as follows: * `helper` defines whether or not to generate helpers. Defaults to `true`. * `integration_tool` defines which integration tool to use to generate integration tests. Defaults to `:test_unit`. * `system_tests` defines which integration tool to use to generate system tests. Defaults to `:test_unit`. -* `javascripts` turns on the hook for JavaScript files in generators. Used in Rails for when the `scaffold` generator is run. Defaults to `true`. -* `javascript_engine` configures the engine to be used (for eg. coffee) when generating assets. Defaults to `:js`. * `orm` defines which orm to use. Defaults to `false` and will use Active Record by default. * `resource_controller` defines which generator to use for generating a controller when using `rails generate resource`. Defaults to `:controller`. * `resource_route` defines whether a resource route definition should be generated @@ -211,7 +214,7 @@ The full set of methods that can be used in this block are as follows: * `stylesheets` turns on the hook for stylesheets in generators. Used in Rails for when the `scaffold` generator is run, but this hook can be used in other generates as well. Defaults to `true`. * `stylesheet_engine` configures the stylesheet engine (for eg. sass) to be used when generating assets. Defaults to `:css`. * `scaffold_stylesheet` creates `scaffold.css` when generating a scaffolded resource. Defaults to `true`. -* `test_framework` defines which test framework to use. Defaults to `false` and will use Minitest by default. +* `test_framework` defines which test framework to use. Defaults to `false` and will use minitest by default. * `template_engine` defines which template engine to use, such as ERB or Haml. Defaults to `:erb`. ### Configuring Middleware @@ -275,7 +278,7 @@ config.middleware.delete Rack::MethodOverride All these configuration options are delegated to the `I18n` library. -* `config.i18n.available_locales` whitelists the available locales for the app. Defaults to all locale keys found in locale files, usually only `:en` on a new application. +* `config.i18n.available_locales` defines the permitted available locales for the app. Defaults to all locale keys found in locale files, usually only `:en` on a new application. * `config.i18n.default_locale` sets the default locale of an application used for i18n. Defaults to `:en`. @@ -307,7 +310,7 @@ All these configuration options are delegated to the `I18n` library. ### Configuring Active Model -* `config.active_model.i18n_full_message` is a boolean value which controls whether the `full_message` error format can be overridden at the attribute or model level in the locale files. This is `false` by default. +* `config.active_model.i18n_customize_full_message` is a boolean value which controls whether the `full_message` error format can be overridden at the attribute or model level in the locale files. This is `false` by default. ### Configuring Active Record @@ -374,7 +377,7 @@ All these configuration options are delegated to the `I18n` library. Defaults to `false`. * `config.active_record.use_schema_cache_dump` enables users to get schema cache information - from `db/schema_cache.yml` (generated by `bin/rails db:schema:cache:dump`), instead of + from `db/schema_cache.yml` (generated by `rails db:schema:cache:dump`), instead of having to send a query to the database to get this information. Defaults to `true`. @@ -382,27 +385,13 @@ The MySQL adapter adds one additional configuration option: * `ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans` controls whether Active Record will consider all `tinyint(1)` columns as booleans. Defaults to `true`. -The SQLite3Adapter adapter adds one additional configuration option: - -* `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer` -indicates whether boolean values are stored in sqlite3 databases as 1 and 0 or -'t' and 'f'. Leaving `ActiveRecord::ConnectionAdapters::SQLite3Adapter.represent_boolean_as_integer` -set to false is deprecated. SQLite databases have used 't' and 'f' to serialize -boolean values and must have old data converted to 1 and 0 (its native boolean -serialization) before setting this flag to true. Conversion can be accomplished -by setting up a Rake task which runs - - ```ruby - ExampleModel.where("boolean_column = 't'").update_all(boolean_column: 1) - ExampleModel.where("boolean_column = 'f'").update_all(boolean_column: 0) - ``` - - for all models and all boolean columns, after which the flag must be set to true -by adding the following to your `application.rb` file: +The PostgreSQL adapter adds one additional configuration option: - ```ruby - Rails.application.config.active_record.sqlite3.represent_boolean_as_integer = true - ``` +* `ActiveRecord::ConnectionAdapters::PostgreSQLAdapter.create_unlogged_tables` + controls whether database tables created should be "unlogged," which can speed + up performance but adds a risk of data loss if the database crashes. It is + highly recommended that you do not enable this in a production environment. + Defaults to `false` in all environments. The schema dumper adds two additional configuration options: @@ -436,7 +425,7 @@ The schema dumper adds two additional configuration options: * `config.action_controller.per_form_csrf_tokens` configures whether CSRF tokens are only valid for the method/action they were generated for. -* `config.action_controller.default_protect_from_forgery` determines whether forgery protection is added on `ActionController:Base`. This is false by default, but enabled when loading defaults for Rails 5.2. +* `config.action_controller.default_protect_from_forgery` determines whether forgery protection is added on `ActionController:Base`. This is false by default. * `config.action_controller.relative_url_root` can be used to tell Rails that you are [deploying to a subdirectory](configuring.html#deploy-to-a-subdirectory-relative-url-root). The default is `ENV['RAILS_RELATIVE_URL_ROOT']`. @@ -444,7 +433,7 @@ The schema dumper adds two additional configuration options: * `config.action_controller.action_on_unpermitted_parameters` enables logging or raising an exception if parameters that are not explicitly permitted are found. Set to `:log` or `:raise` to enable. The default value is `:log` in development and test environments, and `false` in all other environments. -* `config.action_controller.always_permitted_parameters` sets a list of whitelisted parameters that are permitted by default. The default values are `['controller', 'action']`. +* `config.action_controller.always_permitted_parameters` sets a list of permitted parameters that are permitted by default. The default values are `['controller', 'action']`. * `config.action_controller.enable_fragment_cache_logging` determines whether to log fragment cache reads and writes in verbose format as follows: @@ -516,6 +505,9 @@ Defaults to `'signed cookie'`. signed and encrypted cookies use the AES-256-GCM cipher or the older AES-256-CBC cipher. It defaults to `true`. +* `config.action_dispatch.use_cookies_with_metadata` enables writing + cookies with the purpose and expiry metadata embedded. It defaults to `true`. + * `config.action_dispatch.perform_deep_munge` configures whether `deep_munge` method should be performed on the parameters. See [Security Guide](security.html#unsafe-query-generation) for more information. It defaults to `true`. @@ -591,7 +583,7 @@ Defaults to `'signed cookie'`. The default setting is `true`, which uses the partial at `/admin/articles/_article.erb`. Setting the value to `false` would render `/articles/_article.erb`, which is the same behavior as rendering from a non-namespaced controller such as `ArticlesController`. * `config.action_view.raise_on_missing_translations` determines whether an - error should be raised for missing translations. + error should be raised for missing translations. This defaults to `false`. * `config.action_view.automatically_disable_submit_tag` determines whether `submit_tag` should automatically disable on click, this defaults to `true`. @@ -604,12 +596,28 @@ Defaults to `'signed cookie'`. * `config.action_view.default_enforce_utf8` determines whether forms are generated with a hidden tag that forces older versions of Internet Explorer to submit forms encoded in UTF-8. This defaults to `false`. -* `config.action_view.finalize_compiled_template_methods` determines - whether the methods on `ActionView::CompiledTemplates` that templates - compile themselves to are removed when template instances are - destroyed by the garbage collector. This helps prevent memory leaks in - development mode, but for large test suites, disabling this option in - the test environment can improve performance. This defaults to `true`. + +### Configuring Action Mailbox + +`config.action_mailbox` provides the following configuration options: + +* `config.action_mailbox.logger` contains the logger used by Action Mailbox. It accepts a logger conforming to the interface of Log4r or the default Ruby Logger class. The default is `Rails.logger`. + + ```ruby + config.action_mailbox.logger = ActiveSupport::Logger.new(STDOUT) + ``` + +* `config.action_mailbox.incinerate_after` accepts an `ActiveSupport::Duration` indicating how long after processing `ActionMailbox::InboundEmail` records should be destroyed. It defaults to `30.days`. + + ```ruby + # Incinerate inbound emails 14 days after processing. + config.action_mailbox.incinerate_after = 14.days + ``` + +* `config.action_mailbox.queues.incineration` accepts a symbol indicating the Active Job queue to use for incineration jobs. It defaults to `:action_mailbox_incineration`. + +* `config.action_mailbox.queues.routing` accepts a symbol indicating the Active Job queue to use for routing jobs. It defaults to `:action_mailbox_routing`. + ### Configuring Action Mailer @@ -690,6 +698,8 @@ There are a number of settings available on `config.action_mailer`: * `config.action_mailer.perform_caching` specifies whether the mailer templates should perform fragment caching or not. By default this is `false` in all environments. +* `config.action_mailer.delivery_job` specifies delivery job for mail. Defaults to `ActionMailer::DeliveryJob`. + ### Configuring Active Support @@ -707,7 +717,7 @@ There are a few configuration options available in Active Support: * `config.active_support.use_sha1_digests` specifies whether to use SHA-1 instead of MD5 to generate non-sensitive digests, such as the ETag header. Defaults to false. -* `config.active_support.use_authenticated_message_encryption` specifies whether to use AES-256-GCM authenticated encryption as the default cipher for encrypting messages instead of AES-256-CBC. This is false by default, but enabled when loading defaults for Rails 5.2. +* `config.active_support.use_authenticated_message_encryption` specifies whether to use AES-256-GCM authenticated encryption as the default cipher for encrypting messages instead of AES-256-CBC. This is false by default. * `ActiveSupport::Logger.silencer` is set to `false` to disable the ability to silence logging in a block. The default is `true`. @@ -717,13 +727,13 @@ There are a few configuration options available in Active Support: * `ActiveSupport::Deprecation.silence` takes a block in which all deprecation warnings are silenced. -* `ActiveSupport::Deprecation.silenced` sets whether or not to display deprecation warnings. +* `ActiveSupport::Deprecation.silenced` sets whether or not to display deprecation warnings. The default is `false`. ### Configuring Active Job `config.active_job` provides the following configuration options: -* `config.active_job.queue_adapter` sets the adapter for the queueing backend. The default adapter is `:async`. For an up-to-date list of built-in adapters see the [ActiveJob::QueueAdapters API documentation](http://api.rubyonrails.org/classes/ActiveJob/QueueAdapters.html). +* `config.active_job.queue_adapter` sets the adapter for the queuing backend. The default adapter is `:async`. For an up-to-date list of built-in adapters see the [ActiveJob::QueueAdapters API documentation](https://api.rubyonrails.org/classes/ActiveJob/QueueAdapters.html). ```ruby # Be sure to have the adapter's gem in your Gemfile @@ -774,6 +784,8 @@ There are a few configuration options available in Active Support: * `config.active_job.custom_serializers` allows to set custom argument serializers. Defaults to `[]`. +* `config.active_job.return_false_on_aborted_enqueue` change the return value of `#enqueue` to false instead of the job instance when the enqueuing is aborted. Defaults to `false`. + ### Configuring Action Cable * `config.action_cable.url` accepts a string for the URL for where @@ -785,6 +797,9 @@ main application. You can set this as nil to not mount Action Cable as part of your normal Rails server. +You can find more detailed configuration options in the +[Action Cable Overview](action_cable_overview.html#configuration). + ### Configuring Active Storage @@ -805,15 +820,21 @@ normal Rails server. config.active_storage.paths[:ffprobe] = '/usr/local/bin/ffprobe' ``` -* `config.active_storage.variable_content_types` accepts an array of strings indicating the content types that Active Storage can transform through ImageMagick. The default is `%w(image/png image/gif image/jpg image/jpeg image/vnd.adobe.photoshop image/vnd.microsoft.icon)`. +* `config.active_storage.variable_content_types` accepts an array of strings indicating the content types that Active Storage can transform through ImageMagick. The default is `%w(image/png image/gif image/jpg image/jpeg image/pjpeg image/tiff image/vnd.adobe.photoshop image/vnd.microsoft.icon)`. * `config.active_storage.content_types_to_serve_as_binary` accepts an array of strings indicating the content types that Active Storage will always serve as an attachment, rather than inline. The default is `%w(text/html text/javascript image/svg+xml application/postscript application/x-shockwave-flash text/xml application/xml application/xhtml+xml)`. -* `config.active_storage.queue` can be used to set the name of the Active Job queue used to perform jobs like analyzing the content of a blob or purging a blog. +* `config.active_storage.queues.analysis` accepts a symbol indicating the Active Job queue to use for analysis jobs. When this option is `nil`, analysis jobs are sent to the default Active Job queue (see `config.active_job.default_queue_name`). + + ```ruby + config.active_storage.queues.analysis = :low_priority + ``` + +* `config.active_storage.queues.purge` accepts a symbol indicating the Active Job queue to use for purge jobs. When this option is `nil`, purge jobs are sent to the default Active Job queue (see `config.active_job.default_queue_name`). ```ruby - config.active_storage.queue = :low_priority + config.active_storage.queues.purge = :low_priority ``` * `config.active_storage.logger` can be used to set the logger used by Active Storage. Accepts a logger conforming to the interface of Log4r or the default Ruby Logger class. @@ -829,6 +850,47 @@ text/javascript image/svg+xml application/postscript application/x-shockwave-fla The default is 5 minutes. +* `config.active_storage.routes_prefix` can be used to set the route prefix for the routes served by Active Storage. Accepts a string that will be prepended to the generated routes. + + ```ruby + config.active_storage.routes_prefix = '/files' + ``` + + The default is `/rails/active_storage` + +### Results of `load_defaults` + +#### With '5.0': + +- `config.action_controller.per_form_csrf_tokens`: `true` +- `config.action_controller.forgery_protection_origin_check`: `true` +- `ActiveSupport.to_time_preserves_timezone`: `true` +- `config.active_record.belongs_to_required_by_default`: `true` +- `config.ssl_options`: `{ hsts: { subdomains: true } }` + +#### With '5.1': + +- `config.assets.unknown_asset_fallback`: `false` +- `config.action_view.form_with_generates_remote_forms`: `true` + +#### With '5.2': + +- `config.active_record.cache_versioning`: `true` +- `action_dispatch.use_authenticated_cookie_encryption`: `true` +- `config.active_support.use_authenticated_message_encryption`: `true` +- `config.active_support.use_sha1_digests`: `true` +- `config.action_controller.default_protect_from_forgery`: `true` +- `config.action_view.form_with_generates_ids`: `true` + +#### With '6.0': + +- `config.action_view.default_enforce_utf8`: `false` +- `config.action_dispatch.use_cookies_with_metadata`: `true` +- `config.action_mailer.delivery_job`: `"ActionMailer::MailDeliveryJob"` +- `config.active_job.return_false_on_aborted_enqueue`: `true` +- `config.active_storage.queues.analysis`: `:active_storage_analysis` +- `config.active_storage.queues.purge`: `:active_storage_purge` + ### Configuring a Database Just about every Rails application will interact with a database. You can connect to the database by setting an environment variable `ENV['DATABASE_URL']` or by using a configuration file called `config/database.yml`. @@ -907,8 +969,16 @@ development: $ echo $DATABASE_URL postgresql://localhost/my_database -$ bin/rails runner 'puts ActiveRecord::Base.configurations' -{"development"=>{"adapter"=>"postgresql", "host"=>"localhost", "database"=>"my_database"}} +$ rails runner 'puts ActiveRecord::Base.configurations' +#<ActiveRecord::DatabaseConfigurations:0x00007fd50e209a28> + +$ rails runner 'puts ActiveRecord::Base.configurations.inspect' +#<ActiveRecord::DatabaseConfigurations:0x00007fc8eab02880 @configurations=[ + #<ActiveRecord::DatabaseConfigurations::UrlConfig:0x00007fc8eab020b0 + @env_name="development", @spec_name="primary", + @config={"adapter"=>"postgresql", "database"=>"my_database", "host"=>"localhost"} + @url="postgresql://localhost/my_database"> + ] ``` Here the adapter, host, and database match the information in `ENV['DATABASE_URL']`. @@ -924,8 +994,16 @@ development: $ echo $DATABASE_URL postgresql://localhost/my_database -$ bin/rails runner 'puts ActiveRecord::Base.configurations' -{"development"=>{"adapter"=>"postgresql", "host"=>"localhost", "database"=>"my_database", "pool"=>5}} +$ rails runner 'puts ActiveRecord::Base.configurations' +#<ActiveRecord::DatabaseConfigurations:0x00007fd50e209a28> + +$ rails runner 'puts ActiveRecord::Base.configurations.inspect' +#<ActiveRecord::DatabaseConfigurations:0x00007fc8eab02880 @configurations=[ + #<ActiveRecord::DatabaseConfigurations::UrlConfig:0x00007fc8eab020b0 + @env_name="development", @spec_name="primary", + @config={"adapter"=>"postgresql", "database"=>"my_database", "host"=>"localhost", "pool"=>5} + @url="postgresql://localhost/my_database"> + ] ``` Since pool is not in the `ENV['DATABASE_URL']` provided connection information its information is merged in. Since `adapter` is duplicate, the `ENV['DATABASE_URL']` connection information wins. @@ -940,8 +1018,16 @@ development: $ echo $DATABASE_URL postgresql://localhost/my_database -$ bin/rails runner 'puts ActiveRecord::Base.configurations' -{"development"=>{"adapter"=>"sqlite3", "database"=>"NOT_my_database"}} +$ rails runner 'puts ActiveRecord::Base.configurations' +#<ActiveRecord::DatabaseConfigurations:0x00007fd50e209a28> + +$ rails runner 'puts ActiveRecord::Base.configurations.inspect' +#<ActiveRecord::DatabaseConfigurations:0x00007fc8eab02880 @configurations=[ + #<ActiveRecord::DatabaseConfigurations::UrlConfig:0x00007fc8eab020b0 + @env_name="development", @spec_name="primary", + @config={"adapter"=>"sqlite3", "database"=>"NOT_my_database"} + @url="sqlite3:NOT_my_database"> + ] ``` Here the connection information in `ENV['DATABASE_URL']` is ignored, note the different adapter and database name. @@ -979,7 +1065,7 @@ If you choose to use MySQL or MariaDB instead of the shipped SQLite3 database, y ```yaml development: adapter: mysql2 - encoding: utf8 + encoding: utf8mb4 database: blog_development pool: 5 username: root @@ -989,6 +1075,16 @@ development: If your development database has a root user with an empty password, this configuration should work for you. Otherwise, change the username and password in the `development` section as appropriate. +NOTE: If your MySQL version is 5.5 or 5.6 and want to use the `utf8mb4` character set by default, please configure your MySQL server to support the longer key prefix by enabling `innodb_large_prefix` system variable. + +Advisory Locks are enabled by default on MySQL and are used to make database migrations concurrent safe. You can disable advisory locks by setting `advisory_locks` to `false`: + +```yaml +production: + adapter: mysql2 + advisory_locks: false +``` + #### Configuring a PostgreSQL Database If you choose to use PostgreSQL, your `config/database.yml` will be customized to use PostgreSQL databases: @@ -1001,12 +1097,13 @@ development: pool: 5 ``` -Prepared Statements are enabled by default on PostgreSQL. You can disable prepared statements by setting `prepared_statements` to `false`: +By default Active Record uses database features like prepared statements and advisory locks. You might need to disable those features if you're using an external connection pooler like PgBouncer: ```yaml production: adapter: postgresql prepared_statements: false + advisory_locks: false ``` If enabled, Active Record will create up to `1000` prepared statements per database connection by default. To modify this behavior you can set `statement_limit` to a different value: @@ -1065,7 +1162,7 @@ Imagine you have a server which mirrors the production environment but is only u That environment is no different than the default ones, start a server with `rails server -e staging`, a console with `rails console -e staging`, `Rails.env.staging?` works, etc. -### Deploy to a subdirectory (relative url root) +### Deploy to a subdirectory (relative URL root) By default Rails expects that your application is running at the root (eg. `/`). This section explains how to run your application inside a directory. @@ -1144,6 +1241,8 @@ Using Initializer Files After loading the framework and any gems in your application, Rails turns to loading initializers. An initializer is any Ruby file stored under `config/initializers` in your application. You can use initializers to hold configuration settings that should be made after all of the frameworks and gems are loaded, such as options to configure settings for these parts. +NOTE: There is no guarantee that your initializers will run after all the gem initializers, so any initialization code that depends on a given gem having been initialized should go into a `config.after_initialize` block. + NOTE: You can use subfolders to organize your initializers if you like, because Rails will look into the whole file hierarchy from the initializers folder on down. TIP: While Rails supports numbering of initializer file names for load ordering purposes, a better technique is to place any code that need to load in a specific order within the same file. This reduces file name churn, makes dependencies more explicit, and can help surface new concepts within your application. @@ -1351,7 +1450,7 @@ Custom configuration You can configure your own code through the Rails configuration object with custom configuration under either the `config.x` namespace, or `config` directly. The key difference between these two is that you should be using `config.x` if you -are defining _nested_ configuration (ex: `config.x.nested.nested.hi`), and just +are defining _nested_ configuration (ex: `config.x.nested.hi`), and just `config` for _single level_ configuration (ex: `config.hello`). ```ruby |