- Defined in:
Makes a unique request id available to the action_dispatch.request_id env variable (which is then accessible through ActionDispatch::Request#uuid) and sends the same id to the client via the X-Request-Id header.
The unique request id is either based off 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.
Instance Method Summary collapse
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# File 'lib/action_dispatch/middleware/request_id.rb', line 16 def initialize(app) @app = app end
Instance Method Details
#call(env) ⇒ Object
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# File 'lib/action_dispatch/middleware/request_id.rb', line 20 def call(env) env["action_dispatch.request_id"] = external_request_id(env) || internal_request_id status, headers, body = @app.call(env) headers["X-Request-Id"] = env["action_dispatch.request_id"] [ status, headers, body ] end