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
- .new(app, header:) ⇒ RequestId constructor
Instance Method Summary
Constructor Details
.new(app, header:) ⇒ RequestId
# File 'actionpack/lib/action_dispatch/middleware/request_id.rb', line 20
def initialize(app, header:) @app = app @header = header end
Instance Method Details
#call(env)
[ GitHub ]# File 'actionpack/lib/action_dispatch/middleware/request_id.rb', line 25
def call(env) req = ActionDispatch::Request.new env req.request_id = make_request_id(req.headers[@header]) @app.call(env).tap { |_status, headers, _body| headers[@header] = req.request_id } end