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Class: Rails::HealthController

Relationships & Source Files
Super Chains via Extension / Inclusion / Inheritance
Class Chain:
Instance Chain:
self, ::ActionController::Base, ::ActionController::ParamsWrapper, ::ActionController::Instrumentation, ::ActionController::Rescue, ::ActiveSupport::Rescuable, ::ActionController::Logging, ::ActionController::DefaultHeaders, ::ActionController::HttpAuthentication::Token::ControllerMethods, ::ActionController::HttpAuthentication::Digest::ControllerMethods, ::ActionController::HttpAuthentication::Basic::ControllerMethods, ::ActionController::DataStreaming, ::ActionController::Streaming, ::ActionController::RequestForgeryProtection, ::AbstractController::Callbacks, ::ActiveSupport::Callbacks, ::ActionController::FormBuilder, ::ActionController::ParameterEncoding, ::ActionController::StrongParameters, ::ActionController::MimeResponds, ::ActionController::Caching, ::ActionController::EtagWithFlash, ::ActionController::EtagWithTemplateDigest, ::ActionController::ConditionalGet, ::ActionController::Head, ::ActionController::Renderers::All, ::ActionController::Renderers, ::ActionController::Rendering, ::ActionView::Layouts, ::ActionView::Rendering, ::ActionController::Redirecting, ::ActiveSupport::Benchmarkable, ::ActionController::UrlFor, ::AbstractController::UrlFor, ::ActionDispatch::Routing::UrlFor, ::ActionDispatch::Routing::PolymorphicRoutes, ::ActionController::Helpers, ::AbstractController::Helpers, ::ActiveSupport::Deprecation::DeprecatedConstantAccessor, ::AbstractController::Translation, ::AbstractController::Rendering, ::ActionView::ViewPaths, ::ActionController::Metal, ::AbstractController::Base, ::ActiveSupport::Configurable
Inherits: ActionController::Base
Defined in: railties/lib/rails/health_controller.rb

Overview

Built-in Health Check Endpoint

Rails also comes with a built-in health check endpoint that is reachable at the /up path. This endpoint will return a 200 status code if the app has booted with no exceptions, and a 500 status code otherwise.

In production, many applications are required to report their status upstream, whether it’s to an uptime monitor that will page an engineer when things go wrong, or a load balancer or Kubernetes controller used to determine a pod’s health. This health check is designed to be a one-size fits all that will work in many situations.

While any newly generated Rails applications will have the health check at /up, you can configure the path to be anything you’d like in your "config/routes.rb":

Rails.application.routes.draw do
  get "healthz" => "rails/health#show", as: :rails_health_check
end

The health check will now be accessible via the /healthz path.

NOTE: This endpoint does not reflect the status of all of your application’s dependencies, such as the database or redis cluster. Replace "rails/health#show" with your own controller action if you have application specific needs.

Think carefully about what you want to check as it can lead to situations where your application is being restarted due to a third-party service going bad. Ideally, you should design your application to handle those outages gracefully.

Constant Summary

::AbstractController::Rendering - Included

DEFAULT_PROTECTED_INSTANCE_VARIABLES

::ActionController::Redirecting - Included

ILLEGAL_HEADER_VALUE_REGEX

::ActionController::Rendering - Included

RENDER_FORMATS_IN_PRIORITY

::ActionController::Renderers - Included

RENDERERS

::ActiveSupport::Callbacks - Included

CALLBACK_FILTER_TYPES

::ActionController::RequestForgeryProtection - Included

AUTHENTICITY_TOKEN_LENGTH, CSRF_TOKEN, GLOBAL_CSRF_TOKEN_IDENTIFIER, NULL_ORIGIN_MESSAGE

::ActionController::ParamsWrapper - Included

EXCLUDE_PARAMETERS

::ActionController::Base - Inherited

MODULES, PROTECTED_IVARS

Class Attribute Summary

::ActionController::Metal - Inherited

::AbstractController::Base - Inherited

.abstract?
.supports_path?

Returns true if the given controller is capable of rendering a path.

Class Method Summary

::ActionController::Base - Inherited

.without_modules

Shortcut helper that returns all the modules included in ::ActionController::Base except the ones passed as arguments:

::ActionController::Metal - Inherited

.action

Returns a Rack endpoint for the given action name.

.controller_name

Returns the last part of the controller’s name, underscored, without the ending Controller.

.dispatch

Direct dispatch to the controller.

.make_response!,
.middleware

The middleware stack used by this controller.

.new,
.use

Pushes the given Rack middleware and its arguments to the bottom of the middleware stack.

::AbstractController::Base - Inherited

.abstract,
.abstract!

Define a controller as abstract.

.action_methods

A list of method names that should be considered actions.

.clear_action_methods!

action_methods are cached and there is sometimes a need to refresh them.

.controller_path

Returns the full controller name, underscored, without the ending Controller.

.internal_methods

A list of all internal methods for a controller.

.method_added

Refresh the cached action_methods when a new action_method is added.

::ActiveSupport::DescendantsTracker - Extended

descendants

See additional method definition at line 109.

subclasses

Instance Attribute Summary

::ActionController::Instrumentation - Included

::ActionController::Rescue - Included

#rescue_handlers, #rescue_handlers?,
#show_detailed_exceptions?

Override this method if you want to customize when detailed exceptions must be shown.

::ActionController::RequestForgeryProtection - Included

#_helper_methods, #_helper_methods?, #raise_on_missing_callback_actions,
#any_authenticity_token_valid?

Checks if any of the authenticity tokens from the request are valid.

#marked_for_same_origin_verification?

If the verify_authenticity_token before_action ran, verify that JavaScript responses are only served to same-origin GET requests.

#non_xhr_javascript_response?

Check for cross-origin JavaScript responses.

#protect_against_forgery?

Checks if the controller allows forgery protection.

#valid_request_origin?

Checks if the request originated from the same origin by looking at the Origin header.

#verified_request?

Returns true or false if a request is verified.

::AbstractController::Callbacks - Included

::ActionController::StrongParameters - Included

#params

Returns a new ::ActionController::Parameters object that has been instantiated with the request.parameters.

#params=

Assigns the given value to the params hash.

::ActionController::EtagWithFlash - Included

::ActionController::EtagWithTemplateDigest - Included

::ActionController::Renderers::All - Included

::ActionView::Layouts - Included

#action_has_layout=,
#action_has_layout?

Controls whether an action should be rendered using a layout.

::ActionView::Rendering - Included

::ActionController::Redirecting - Included

::AbstractController::UrlFor - Included

::ActionController::Helpers - Included

::ActionView::ViewPaths - Included

::ActionController::Metal - Inherited

#content_type, #headers, #location, #media_type, #middleware_stack, #middleware_stack?, #params, #params=,
#performed?

Tests if render or redirect has already happened.

#request

:attr_reader: request.

#response

:attr_reader: response.

#response=

Assign the response and mark it as committed.

#response_body=, #session, #status

::AbstractController::Base - Inherited

#action_name

Returns the name of the action this controller is processing.

#formats

Returns the formats that can be processed by the controller.

#performed?

Tests if a response body is set.

#response_body

Returns the body of the HTTP response sent by the controller.

Instance Method Summary

::ActionController::Instrumentation - Included

#redirect_to, #render, #send_data, #send_file,
#append_info_to_payload

Every time after an action is processed, this method is invoked with the payload, so you can add more information.

#cleanup_view_runtime

A hook which allows you to clean up any time, wrongly taken into account in views, like database querying time.

::ActiveSupport::Rescuable - Included

#rescue_with_handler

Delegates to the class method, but uses the instance as the subject for rescue_from handlers (method calls, instance_exec blocks).

::ActionController::HttpAuthentication::Token::ControllerMethods - Included

#authenticate_or_request_with_http_token

Authenticate using an HTTP Bearer token, or otherwise render an HTTP header requesting the client to send a Bearer token.

#authenticate_with_http_token

Authenticate using an HTTP Bearer token.

#request_http_token_authentication

Render an HTTP header requesting the client to send a Bearer token for authentication.

::ActionController::HttpAuthentication::Digest::ControllerMethods - Included

#authenticate_or_request_with_http_digest

Authenticate using an HTTP Digest, or otherwise render an HTTP header requesting the client to send a Digest.

#authenticate_with_http_digest

Authenticate using an HTTP Digest.

#request_http_digest_authentication

Render an HTTP header requesting the client to send a Digest for authentication.

::ActionController::HttpAuthentication::Basic::ControllerMethods - Included

::ActionController::DataStreaming - Included

#send_data

Sends the given binary data to the browser.

#send_file

Sends the file.

::ActionController::RequestForgeryProtection - Included

#commit_csrf_token, #initialize, #reset_csrf_token, #compare_with_global_token, #compare_with_real_token, #csrf_token_hmac,
#form_authenticity_param

The form’s authenticity parameter.

#form_authenticity_token

Creates the authenticity token for the current request.

#global_csrf_token, #handle_unverified_request,
#mark_for_same_origin_verification!

GET requests are checked for cross-origin JavaScript after rendering.

#mask_token, #normalize_action_path, #per_form_csrf_token, #real_csrf_token,
#request_authenticity_tokens

Possible authenticity tokens sent in the request.

#unmask_token,
#valid_authenticity_token?

Checks the client’s masked token to see if it matches the session token.

#valid_per_form_csrf_token?,
#verify_authenticity_token

The actual before_action that is used to verify the CSRF token.

#verify_same_origin_request

If verify_authenticity_token was run (indicating that we have forgery protection enabled for this request) then also verify that we aren’t serving an unauthorized cross-origin response.

#xor_byte_strings

::ActiveSupport::Callbacks - Included

#run_callbacks

Runs the callbacks for the given event.

::ActionController::FormBuilder - Included

#default_form_builder

Default form builder for the controller.

::ActionController::MimeResponds - Included

#respond_to

Without web-service support, an action which collects the data for displaying a list of people might look something like this:

::ActionController::ConditionalGet - Included

#expires_in

Sets the Cache-Control header, overwriting existing directives.

#expires_now

Sets an HTTP 1.1 Cache-Control header of no-cache.

#fresh_when

Sets the etag, last_modified, or both on the response, and renders a 304 Not Modified response if the request is already fresh.

#http_cache_forever

Cache or yield the block.

#no_store

Sets an HTTP 1.1 Cache-Control header of no-store.

#stale?

Sets the etag and/or last_modified on the response and checks them against the request.

::ActionController::Head - Included

#head

Returns a response that has no content (merely headers).

::ActionController::Renderers - Included

#_render_to_body_with_renderer,
#render_to_body

Called by render in ::AbstractController::Rendering which sets the return value as the response_body.

::ActionController::Rendering - Included

#render

Renders a template and assigns the result to self.response_body.

#render_to_string

Similar to #render, but only returns the rendered template as a string, instead of setting self.response_body.

::ActionView::Rendering - Included

::ActionController::Redirecting - Included

#redirect_back

Soft deprecated alias for #redirect_back_or_to where the fallback_location location is supplied as a keyword argument instead of the first positional argument.

#redirect_back_or_to

Redirects the browser to the page that issued the request (the referrer) if possible, otherwise redirects to the provided default fallback location.

#redirect_to

Redirects the browser to the target specified in options.

#url_from

Verifies the passed location is an internal URL that’s safe to redirect to and returns it, or nil if not.

::ActiveSupport::Benchmarkable - Included

#benchmark

Allows you to measure the execution time of a block in a template and records the result to the log.

::ActionController::UrlFor - Included

::AbstractController::UrlFor - Included

::ActionDispatch::Routing::UrlFor - Included

#initialize,
#route_for

Allows calling direct or regular named route.

#url_for

Generate a URL based on the options provided, default_url_options, and the routes defined in config/routes.rb.

#url_options

Hook overridden in controller to add request information with default_url_options.

#_routes_context, #_with_routes

::ActionDispatch::Routing::PolymorphicRoutes - Included

#polymorphic_path

Returns the path component of a URL for the given record.

#polymorphic_url

Constructs a call to a named RESTful route for the given record and returns the resulting URL string.

::ActionController::Helpers - Included

#helpers

Provides a proxy to access helper methods from outside the view.

::AbstractController::Helpers - Included

::AbstractController::Translation - Included

#l
#localize

Delegates to I18n.localize.

#t
#translate

Delegates to I18n.translate.

::AbstractController::Rendering - Included

#render

Normalizes arguments and options, and then delegates to render_to_body and sticks the result in self.response_body.

#render_to_body

Performs the actual template rendering.

#render_to_string

Similar to #render, but only returns the rendered template as a string, instead of setting self.response_body.

#rendered_format

Returns Content-Type of rendered content.

#view_assigns

This method should return a hash with assigns.

#_normalize_args

Normalize args by converting render "foo" to render action: "foo" and render "foo/bar" to render file: "foo/bar".

#_normalize_options

Normalize options.

#_process_options

Process extra options.

::ActionView::ViewPaths - Included

#any_templates?,
#append_view_path

Append a path to the list of view paths for the current LookupContext.

#details_for_lookup,
#lookup_context

LookupContext is the object responsible for holding all information required for looking up templates, i.e. view paths and details.

#prepend_view_path

Prepend a path to the list of view paths for the current LookupContext.

#template_exists?

::ActionController::Metal - Inherited

#controller_name

Delegates to the class’s .controller_name.

#reset_session,
#url_for

Basic url_for that can be overridden for more robust functionality.

::AbstractController::Base - Inherited

#action_methods

Delegates to the class’s .action_methods.

#available_action?

Returns true if a method for the action is available and can be dispatched, false otherwise.

#controller_path

Delegates to the class’s .controller_path.

#process

Calls the action going through the entire Action Dispatch stack.

::ActiveSupport::Configurable - Included

#config

Reads and writes attributes from a configuration OrderedOptions.

Constructor Details

This class inherits a constructor from ActionController::Metal

Instance Method Details

#show

[ GitHub ]

  
# File 'railties/lib/rails/health_controller.rb', line 38

def show
  render_up
end