Module: Rails::Instrumentation::Utils

Defined in:
lib/rails/instrumentation/utils.rb

Class Method Summary collapse

Class Method Details

.register_subscriber(full_name: '', event_name: '', handler_module: nil) ⇒ Object

calls a handler function with name ‘event’ on the handler module. For example, if the handler module is ActionViewSubscriber and the event hook is ‘render_template.action_controller’, full_name is ‘render_template.action_controller’ and event_name is ‘render_template’



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# File 'lib/rails/instrumentation/utils.rb', line 11

def register_subscriber(full_name: '', event_name: '', handler_module: nil)
  ::ActiveSupport::Notifications.subscribe(full_name) do |*args|
    event = ::ActiveSupport::Notifications::Event.new(*args)
    handler_module.send(event_name, event)
  end
end

.tag_error(span, payload) ⇒ Object

according to the ActiveSupport::Notifications documentation, exceptions will be indicated with the presence of the :exception and :exception_object keys. These will be tagged and logged according to the OpenTracing specification.



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# File 'lib/rails/instrumentation/utils.rb', line 38

def tag_error(span, payload)
  if payload.key? :exception_object
    span.record_exception(payload[:exception_object])
  else
    exception = payload[:exception]
    span.set_tag(:error, true)
    span.set_tag(:'sfx.error.kind', exception[0]) 
    span.set_tag(:'sfx.error.message', exception[1])
  end
end

.trace_notification(event:, tags: []) ⇒ Object

takes and event and some set of tags from a handler, and creates a span with the event’s name and the start and finish times.



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# File 'lib/rails/instrumentation/utils.rb', line 20

def trace_notification(event:, tags: [])
  tags = ::Rails::Instrumentation::TAGS.clone.merge(tags)

  span = ::Rails::Instrumentation.tracer.start_span(event.name,
                                                    tags: tags,
                                                    start_time: event.time)

  # tag transaction_id
  span.set_tag('transaction.id', event.transaction_id)
  tag_error(span, event.payload) if event.payload.key? :exception

  span.finish(end_time: event.end)
end