diff options
Diffstat (limited to 'actionpack/lib/action_dispatch/middleware/request_id.rb')
-rw-r--r-- | actionpack/lib/action_dispatch/middleware/request_id.rb | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/actionpack/lib/action_dispatch/middleware/request_id.rb b/actionpack/lib/action_dispatch/middleware/request_id.rb new file mode 100644 index 0000000000..6fff94707c --- /dev/null +++ b/actionpack/lib/action_dispatch/middleware/request_id.rb @@ -0,0 +1,36 @@ +require 'securerandom' +require 'active_support/core_ext/string/access' +require 'active_support/core_ext/object/blank' + +module ActionDispatch + # 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. + class RequestId + def initialize(app) + @app = app + end + + def call(env) + env["action_dispatch.request_id"] = external_request_id(env) || internal_request_id + @app.call(env).tap { |status, headers, body| headers["X-Request-Id"] = env["action_dispatch.request_id"] } + end + + private + def external_request_id(env) + if request_id = env["HTTP_X_REQUEST_ID"].presence + request_id.gsub(/[^\w\-]/, "").first(255) + end + end + + def internal_request_id + SecureRandom.uuid + end + end +end |