class Rapporteur::Checker
The center of the Rapporteur
library, Checker
manages holding and running the custom checks, holding any application error messages, and provides the controller with that data for rendering.
Attributes
Public Class Methods
# File lib/rapporteur/checker.rb, line 11 def initialize @check_list = CheckList.new reset end
Public Instance Methods
Public: Add a pre-built or custom check to your status endpoint. These checks are used to test the state of the world of the application, and need only respond to `#call`.
Once added, the given check will be called and passed an instance of this checker. If everything is good, do nothing! If there is a problem, use `add_error` to add an error message to the checker.
Examples
Rapporteur.add_check { |checker| checker.add_error(:luck, :bad) if rand(2) == 1 }
Returns self. Raises ArgumentError if the given check does not respond to call.
# File lib/rapporteur/checker.rb, line 33 def add_check(object_or_nil_with_block = nil, &block) if block_given? check_list.add(block) elsif object_or_nil_with_block.respond_to?(:call) check_list.add(object_or_nil_with_block) else raise ArgumentError, 'A check must respond to #call.' end self end
Public: Add an error message to the checker in order to have it rendered in the status request.
It is suggested that you use I18n and locale files for these messages, as is done with the pre-built checks. If you're using I18n, you'll need to define `rapporteur.errors.<your key>.<your message>`.
name - A Symbol which indicates the attribute, name, or other identifier
for the check being run.
message - A String/Symbol/Proc to identify the message to provide in a
check failure situation. A String is presented as given. A Symbol will attempt to translate through I18n or default to the String-form of the symbol. A Proc which will be called and the return value will be presented as returned.
i18n_options - A Hash of options (likely variable key/value pairs) to
pass to I18n during translation.
Examples
checker.add_error(:you, "failed.") checker.add_error(:using, :i18n_key_is_better) checker.add_error(:using, :i18n_with_variable, :custom_variable => 'pizza') en: rapporteur: errors: using: i18n_key_is_better: 'Look, localization!' i18n_with_variable: 'Look, %{custom_variable}!'
Returns self.
# File lib/rapporteur/checker.rb, line 117 def add_error(name, message, i18n_options = {}) errors.add(name, message, i18n_options) self end
Public: Adds a status message for inclusion in the success response.
name - A String containing the name or identifier for your message. This
is unique and may be overriden by other checks using the name message name key.
message - A String/Symbol/Proc containing the message to present to the
user in a successful check sitaution. A String is presented as given. A Symbol will attempt to translate through I18n or default to the String-form of the symbol. A Proc which will be called and the return value will be presented as returned.
Examples
checker.add_message(:repository, 'git@github.com/user/repo.git') checker.add_message(:load, 0.934) checker.add_message(:load, :too_high, :measurement => '0.934')
Returns self.
# File lib/rapporteur/checker.rb, line 144 def add_message(name, message, i18n_options = {}) messages.add(name, message, i18n_options) self end
Internal: Returns a hash of messages suitable for conversion into JSON.
# File lib/rapporteur/checker.rb, line 152 def as_json(_args = {}) messages.to_hash end
Public: Empties all configured checks from the checker. This may be useful for testing and for cases where you might've built up some basic checks but for one reason or another (environment constraint) need to start from scratch.
Returns self.
# File lib/rapporteur/checker.rb, line 51 def clear check_list.clear self end
Internal: Used by Rails' JSON serialization to render error messages.
# File lib/rapporteur/checker.rb, line 159 def errors Thread.current[:rapporteur_errors] ||= MessageList.new(:errors) end
Public: Checks
can call this method to halt any further processing. This is useful for critical or fatal check failures.
For example, if load is too high on a machine you may not want to run any other checks.
Returns true.
# File lib/rapporteur/checker.rb, line 65 def halt! @halted = true end
Internal: Used by Rails' JSON serialization.
# File lib/rapporteur/checker.rb, line 166 def read_attribute_for_serialization(key) messages[key] end
Public: This is the primary execution point for this class. Use run to exercise the configured checker and collect any application errors or data for rendering.
Returns self.
# File lib/rapporteur/checker.rb, line 75 def run reset check_list.each do |object| object.call(self) break if @halted end self end
Private Instance Methods
# File lib/rapporteur/checker.rb, line 176 def messages Thread.current[:rapporteur_messages] ||= MessageList.new(:messages) end
# File lib/rapporteur/checker.rb, line 180 def reset @halted = false messages.clear errors.clear end