123456789_123456789_123456789_123456789_123456789_

Class: ActionDispatch::RequestId

Relationships & Source Files
Inherits: Object
Defined in: actionpack/lib/action_dispatch/middleware/request_id.rb

Overview

Makes a unique request id available to the action_dispatch.request_id env variable (which is then accessible through Request#request_id or the alias Request#uuid) and sends the same id to the client via the X-Request-Id header.

The unique request id is either based on the X-Request-Id header in the request, which would typically be generated by a firewall, load balancer, or the web server, or, if this header is not available, a random uuid. If the header is accepted from the outside world, we sanitize it to a max of 255 chars and alphanumeric and dashes only.

The unique request id can be used to trace a request end-to-end and would typically end up being part of log files from multiple pieces of the stack.

Class Method Summary

Instance Method Summary

Constructor Details

.new(app, header:) ⇒ RequestId

[ GitHub ] 

  


# File 'actionpack/lib/action_dispatch/middleware/request_id.rb', line 25



def initialize(app, header:)
  @app = app
  @header = header
  @env_header = "HTTP_#{header.upcase.tr("-", "_")}"
end


  







Instance Method Details



  

    #call(env)  
  

  [ GitHub ]


  

  


# File 'actionpack/lib/action_dispatch/middleware/request_id.rb', line 31



def call(env)
  req = ActionDispatch::Request.new env
  req.request_id = make_request_id(req.get_header(@env_header))
  @app.call(env).tap { |_status, headers, _body| headers[@header] = req.request_id }
end


  








  

    #internal_request_id   (private)
  

  [ GitHub ]


  

  


# File 'actionpack/lib/action_dispatch/middleware/request_id.rb', line 46



def internal_request_id
  SecureRandom.uuid
end


  








  

    #make_request_id(request_id)   (private)
  

  [ GitHub ]


  

  


# File 'actionpack/lib/action_dispatch/middleware/request_id.rb', line 38



def make_request_id(request_id)
  if request_id.presence
    request_id.gsub(/[^\w\-@]/, "").first(255)
  else
    internal_request_id
  end
end