Class: Rack::RequestId

Inherits:
Object
  • Object
show all
Defined in:
lib/rack/request_id.rb

Overview

Public: Rack middleware that stores the Heroku-Request-Id header in a thread local variable.

Heroku has a labs feature called request_id, which can be used to tracking a request through the system.

app - The Rack app.

Examples

use Rack::LogRequestId

logger.info "request_id=#{Thread.current[:request_id]} Hello world"
# => request_id=a08a6712229fb991c0e5026c246862c7 Hello world

Constant Summary collapse

REQUEST_HEADER = 
'HTTP_HEROKU_REQUEST_ID'.freeze
RESPONSE_HEADER = 
'X-Request-Id'.freeze

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ RequestId

Returns a new instance of RequestId.



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# File 'lib/rack/request_id.rb', line 21

def initialize(app, options = {})
  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/rack/request_id.rb', line 25

def call(env)
  ::RequestId.request_id = env[REQUEST_HEADER]
  status, headers, body = @app.call(env)
  headers[RESPONSE_HEADER] ||= ::RequestId.request_id
  [status, headers, body]
ensure
  ::RequestId.request_id = nil
end